2017 NEC Requirement Guidelines for the Installation of Listed Less-Flammable Liquid-Filled Transformers

These guidelines represent Eaton's understanding and interpretation of the National Electrical Code, UL Classification of Envirotemp FR3 Fluid and FM Global Property Loss Prevention Data Sheets 5-4 - Transformers, Approved Transformer Fluids Standard 6933, FM Approved Transformer Standard 3990 and IEEE standards in effect at the time of this publication. It does not necessarily represent the position of Eaton on the protection and installation of less-flammable transformers.

Eaton

2017 NEC Requirement Guidelines for the Installation of ...

4 Reference Data TD900001EN Effective January 2019 wwwrrr 2017 O r Trrrs * Refer to NFPA 220 for definition of non-combustible or limited combustible Type I and II building construction .

2017-nec-requirement-guidelines-for-installation-of-listed-less-flammable-liquid-filled-transformers-td900001en
2017 NEC Requirement Guidelines Reference Data TD900001EN

COOPER POWER

Effective January 2019 Supersedes March 2011 (R900-20-13)

SERIES

2017 NEC Requirement Guidelines for the Installation of Listed Less-Flammable Liquid-Filled Transformers
General requirements General NEC Transformer Installation Requirements:.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 3 NESC (ANSI C2) Recognition:.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 3
Indoor installation options Table 1: NEC Section 450.23 Requirements ­ Indoor Installations.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 4 Type I and Type II building definition .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 4 NFPA 450.26 information .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 4 Example of indoor installation.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 5
Outdoor installation options Outdoor installation option .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 6 Table 2: NEC Section 450.23 Requirements - Outdoor installations.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 6 NFPA 450.27 information .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 6 Outdoor installation using Conventional Mineral Oil, per IEEE 979. .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 6
Listing options for indoor installations Listing options.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 7 Listing Option A ­ UL Requirements. 8 Table 3: UL® Classification Marking..  8 Fire protection for indoor transformers.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 9 Table 4: Recommended construction for transformer buildings and rooms.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 9 Listing Option B ­ FM Requirements..  10 FM Approved Transformer.. 10 Table 5: FM Pressure Relief Device Required Ratings..  11 Table 6: FM Maximum I2t Let Through Required Ratings.. 11
Listing options for outdoor installations Listing options.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  . 12 Listing Option A ­ UL Requirements. 13 Listing Option B ­ FM Requirements..  13 Separation Distance..  14 Table 7: Separation for exposure protection of main building walls..  14 Table 8: Separation and extent of 2-hour fire barrier for protection of main building walls.. 15 Table 9: Transformer fire exposure to non-combustible building roof where separation from wall is based on 3-hour fire barrier or water spray protection.. 16 Table 10: Minimum separation distance between adjacent transformers.. 16 Outdoors On or Adjacent to Combustible Buildings or Combustible Materials..  17
UL Listing Requirement Highlights for Indoor Installations - Appendix 1 19
UL Listing Requirement Highlights for Outdoor Installations - Appendix 2  20
UL Classified Less-Flammable Liquid & UL Listed & Classified Transformers - Appendix 3  21
FM Listing Requirement Highlights for Indoor Installations - Appendix 4 28
FM Listing Requirement Highlights for Outdoor Installations - Appendix 5 29

These guidelines represent Eaton's understanding and interpretation of the National Electrical Code®, UL® Classification of EnvirotempTM FR3TM Fluid and FM Global Property Loss Prevention Data Sheets 5-4 - Transformers, Approved Transformer Fluids Standard 6933, FM Approved Transformer Standard 3990 and IEEE standards in effect at the time of this publication. It does not necessarily represent the position of Eaton on the protection and installation of less-flammable transformers.

Reference Data TD900001EN
Effective January 2019

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2017 Code Options for the Installation of Listed Less-Flammable Liquid-Filled Transformers

Reference Data TD900001EN
Effective January 2019

General requirements
NEC (NFPA 70) Recognition: These guidelines focus on the requirements of Section 450.23 of the 2017 National Electrical Code (NEC) for the installation of Less-Flammable LiquidInsulated Transformers. Less-flammable liquids are used in transformers where an extra margin of fire safety is important. Typical applications include installations indoors, on rooftops, near buildings, bush and forest fire prone areas and in pedestrian traffic areas.
Less-flammable liquids, also known as high fire point liquids, are transformer dielectric coolants that have a minimum fire point of 300°C. Commonly used fire resistant coolants include high molecular weight hydrocarbons (HMWH), dimethysiloxane, synthetic esters (Envirotemp 200 fluid), and natural esters (Envirotemp FR3 fluid). Two Nationally Recognized Testing Laboratories (NRTL)* Underwriters Laboratories (UL) and FM Global (FM) currently list less-flammable liquids. They also list less-flammable liquid-filled transformers.
Less-flammable liquid-filled transformers were formally recognized by the NEC for indoor installations in 1978. In 1990, the NEC integrated specific less-flammable transformer requirements for outdoor installations into Section 450.23, in effect recognizing less-flammable transformers as inherently safer than conventional oil-filled transformers. Less-flammable transformers, long recognized as an additional safeguard for indoor installations, are becoming increasingly recognized for outdoor installations as well.
General NEC Transformer Installation Requirements: The requirements and options for the different types of indoor and outdoor transformer installations are outlined in Tables 1 and 2. These guidelines also summarize the UL Classification and FM Global Approved installation requirements for less-flammable liquid referred to as "listing" requirements in NEC 450.23.
NEC Section 450.28, Modification of Transformers, requires that when modifications are made to transformers in existing installations that change the transformer type, the transformers must be marked to show the type of insulating liquid installed and the installations must comply with current requirements of the NEC. Examples of changes include replacing a complete transformer (retrofitting) or replacement of the fluid only (retrofilling). Askarel (PCB) and conventional mineral oil-filled transformers can be retrofitted or retrofilled using some types of less-flammable liquids like natural esters. Section 110.34 sets minimum clear work space d imensions around transformers.

NNote:
The intention of this guide is focused on the NEC requirements for the installation of transformers. However, the user of the Guide should be aware that not all transformer installations are under the jurisdiction to require compliance to NEC, such as the NESC, the National Electrical Safety Code. Transformer owned and operated by electric Utilities typically follow the NESC guidelines.
NESC (ANSI C2) Recognition: Utility-owned transformer installations are typically subject to the requirements of the National Electrical Safety Code (NESC), ANSI C2, in lieu of the NEC. Since 1993, the NESC has also recognized the use of less-flammable transformer liquid as an optional fire safeguard for indoor and outdoor transformer installations in Section 152. Other optional fire safeguard methods that may be applied, depending on the degree of fire hazard p resent in the installation, are separation from combustible materials or structures, liquid c onfinement, fire resistant barriers or enclosures, or extinguishing systems.

NNote: EnvirotempTM and FR3TM are licensed trademarks of Cargill, Incorporated.

*Refer to Occupational Safety & Health Administration (OSHA) for complete listing of NRTLs.

2017 Code Options for the Installation of Listed Less-Flammable Liquid-Filled Transformers

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Reference Data TD900001EN
Effective January 2019

Indoor installation options
(Refer to Appendices 1 and 4)
450.23 Less-Flammable Liquid-Insulated Transformers. Transformers insulated with less-flammable liquids that have a fire point of not less than 300°C shall be permitted to be installed in accordance with 450.23(A) or 450.23(B). ***
Table 1. NEC Section 450.23 Requirements ­ (A) Indoor installation. Indoor installations shall be permitted in accordance with one of the following:
(1) In Type I or Type II buildings*, in areas where all of the following requirements are met:
a. The transformer is rated 35,000 volts or less.
b. No combustible materials are stored.
c. A liquid confinement area is provided.
d. The installation complies with all the restrictions provided for in the listing of the liquid.
Informational note: Such restrictions may include, but are not limited to: maximum pressure of the tank, use of a pressure relief valve, appropriate fuse types and proper sizing of overcurrent protection.
(2) e. With an automatic fire extinguishing system and a liquid confinement area, provided the transformer is rated 35,000 volts or less.
(3) f. In accordance with 450.26**
Type I and Type II building definition
Type I ­ Fire-resistive
This concrete and steel structure, called fire resistive when first built at the turn of the century, is supposed to confine a fire by its construction. This type of construction in which the building elements are of non-combustible materials, such as concrete and steel. The roof is also of non-combustible material, such as concrete or steel.
Type II ­ Non-combustible
This type of building has steel or concrete walls, floors, and structural framework similar to type I construction; however, the roof covering material is combustible. The roof covering of a type II building can be a layer of asphalt waterproofing, with a combustible felt paper covering. Another layer of asphalt may be mopped over the felt paper.
NFPA 450.26 information
450.26 Oil-insulated transformers installed indoors.

Oil insulated transformers installed indoors shall be installed in a vault constructed as specified in Part III of this article.
Exception No. 1: Where the total capacity does not exceed 112½ kVA, the vault specified in Part III of this article shall be permitted to be constructed of reinforced concrete that is less than 100 mm (4 in.) thick.
Exception No. 2: Where the nominal voltage does not exceed 1000 volts, a vault shall not be required if suitable arrangements are made to prevent a transformer oil fire from igniting other materials and the total capacity in one location does not exceed 10 kVA in a section of the building classified as combustible or 75 kVA where the surrounding structure is classified as fireresistant construction.
Exception No. 3: Electric furnace transformers that have a total rating not exceeding 75 kVA shall be permitted to be installed without a vault in a building or room of fire-resistant construction, provided suitable arrangements are made to prevent a transformer oil fire from spreading to other combustible material.
Exception No. 4: A transformer that has a total rating not exceeding 75 kVA and a supply voltage of 1000 volts or less that is an integral part of charged-particle-accelerating equipment shall be permitted to be install without a vault in a building or room of non-combustible or fire-resistant construction, providing suitable arrangements are made to prevent a transformer oil fire from spreading to other combustible material.
Exception No. 5: Transformers shall be permitted to be installed in a detached building that does not comply with Part III of this article if neither the building nor its content present a fire hazard to any other building or property, and if the building is used only in supplying electric service and the interior is accessible only to qualified persons.
Exception No. 6: Oil insulated transformers shall be permitted to be used without a vault in portable or mobile surface mining equipment (such as electric excavator) if each of the following conditions are met:
· Provisions are made for draining leaking fluid to the ground
· Safe egress is provided for personnel
· A minimum of 6 mm (1/4 in) steel barrier is provided for personnel protection

* Refer to NFPA 220 for definition of non-combustible or limited combustible Type I and II building construction.
** No additional NEC article 450.23 safeguards are required if one or more of Exceptions 1 - 6 of Section 450.26, Oil-Insulated Transformers Installed Indoors apply.
*** S ection 450.23 (A) published in the 2017 NEC by NFPA included an editorial error in the numbering. This error was corrected by Errata No. 70-17-6 dated July 5, 2018. The strikethroughs shown reflect the corrections NFPA issued with Errata 70-17-6. There were no requirement changes intended to this Section in the 2017 NEC from the 2014 NEC.

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2017 Code Options for the Installation of Listed Less-Flammable Liquid-Filled Transformers

Example ­ Option (A)(1), indoor installation rated  35 kV
Without a vault in Type I or II building*, non-combustible materials with liquid containment pan.

Reference Data TD900001EN
Effective January 2019

*Refer to NFPA 220 for more information about Type I and Type II building construction.

2017 Code Options for the Installation of Listed Less-Flammable Liquid-Filled Transformers

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Reference Data TD900001EN
Effective January 2019

Outdoor installation options
(Refer to Appendices 2 and 5)
Outdoor installations using less-flammable liquid-insulated transformers must comply with NEC section 450.23, which defines the requirements for the two installations options as detailed in Table 2:
Table 2. NEC Section 450.23 Requirements ­ Less-flammable liquid filled transformers shall be permitted to be installed outdoors, attached to, adjacent to, or on the roof of building, where installed according with (1) or (2).
1. For Type I or Type II buildings*, the installation shall comply with all the restrictions provided for in the listing of the liquid.
2. Informational note No. 1: Installations adjacent to combustible material, fire escapes or door and window openings may require additional safeguards such as those listed in 450.27.
Informational note No. 2: Such restrictions may include, but are not limited to: maximum pressure of the tank, use of a pressure relief valve, appropriate fuse types and proper sizing of overcurrent protection.
Or
2. In accordance with 450.27.
3. Informational note No. 1: As used in this section, Type I and Type II buildings refers to Type I and Type II building construction as defined in NFPA 220-2015, Standard on Types of Building Construction. Combustible materials refers to those materials not classified as non-combustible or limited-combustible as defined in NFPA 220-2015, Standard on Types of Building construction.
Informational note No. 2: See definition of Listed in Article 100.
450.27 Oil-insulated transformers installed outdoors.
Combustible material, combustible buildings and parts of buildings, fire escapes, and door and window openings shall be safeguarded from fires originating in oil-insulated transformers installed on roofs, attached to or adjacent to a building or combustible material.
In case where the transformer installation presents a fire hazard, one or more of the following safeguards shall be applied according to the degree of hazard involved:
· Space separation
· Fire resistant barriers
· Automatic fire suppression systems
· Enclosures that confine the oil of a rupture transformer tank

Oil enclosures shall be permitted to consist of fire-resistant dikes, curbed areas or basins, or trenches filled with coarse, crushed stone. Oil enclosures shall be provided with trapped drains where the exposure and the quantity of oil involved are such that removal of oil is important.
Informational Note: For additional information on transformers installed on poles or structures or underground, see ANSI C2-2007, National Electrical Safety Code.
*Refer to NFPA 220 for more information about Type I and Type II building construction.
As in indoor installations, less-flammable liquid-insulated transformers are increasingly recognized as an additional safeguard by insurance underwriters and specifiers for outdoor applications. The degree of fire safety will be significantly increased when a transformer is filled with less-flammable liquid instead of conventional mineral oil. Transformers installed according to the listing requirements of less-flammable liquids will provide an even greater margin of safety.
Outdoor Installations Using Conventional Mineral Oil, per IEEE 979
Spatial separation of outdoor mineral-oil-insulated equipment
Electrical equipment installed outdoors and containing mineral oil should be separated from other equipment, buildings, and the adjacent property line to minimize the impact of a major fire. Spatial separation is an effective method for reducing fire spread or damage from mineral-oil-filled equipment fires.
There are two methods for determining acceptable minimum separation distances. Prescriptive guidelines are presented in 7.2 followed by a performance-based alternative discussed in 7.3. The prescriptive method is most commonly used, but this method may not provide adequate protection for all site conditions. The performance-based method indicates a level of protection that more accurately models the specific site conditions.
Per Section 1.3 General: The predominant dielectric insulating fluid for transformers is mineral oil, and mineral oil constitutes one of the primary fire hazards in the substation. Consequently, much of this guide addresses hazards and protection measures based on mineral oil fires. There are several alternative fluids with improved fire safety properties (higher flash and fire points), known as "less-flammable" dielectric fluids, which have been introduced. Many of these fluids have been recognized as reducing the hazard and the risk of a fire occurring relative to mineral oil. Use of a "less flammable" fluid is one means to reduce the risk of fire at a substation. See 8.4.2 and A.21 for additional information on these fluids.

* Refer to NFPA 220 for definition of non-combustible or limited combustible Type I and II building construction.
** Per NFPA 220, the definition of combustible material refers to material not classified as non-combustible or limited-combustible.

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2017 Code Options for the Installation of Listed Less-Flammable Liquid-Filled Transformers

Reference Data TD900001EN
Effective January 2019

Example of Outdoors on or adjacent to Type I and Type II buildings non-combustible building* and no combustible material stored in the area

NEC Options for Transformer Listing **
Indoor installation
At the time of the publication of this Guide, two nationally recognized testing entities list less-flammable insulating liquids and publish their respective listing requirements:
A. Underwriters Laboratories classifications
B. FM Global Approvals
It is optional which of the listings are used to comply with 450.23.
For indoor installations, if the transformers are provided with less-flammable liquid insulation and are installed without a vault in a Type I or Type II non-combustible building* where no combustible material is storage, it requires:
1) A liquid confinement area be provided.
Liquid containment may include:
- Containment pan
- Curbing
- Room containment (e.g. door sill)
2) The transformer be filled with a listed less-flammable insulating liquid with a minimum of 300°C fire point.
3) The installation complies with all restrictions provided for in the listing of the liquid.
Or
A liquid confinement area, as indicated above and an automatic fire extinguishing system.
If the transformer has a non-listed insulating liquid, provide individual containment for the content of the transformer to prevent spills from flowing to another transformers or important equipment in the room.
Or
It must be installed in a vault complying with the NEC 450 Part III, Transformer vaults.
Section 450.26 may be followed in lieu of any requirements listed in Section 450.23. Exceptions to vault requirements are listed.
Points in Section 450.26 are also valid for less-flammable liquid-filled installations. Construction requirements for vaults are detailed in Part III of Article 450.
Section 450.42 in Part III, Transformer Vaults, allows an exception to the 3-hour vault requirement permitting a 1-hour rated fire resistant rated room if equipped with an automatic extinguishing system.

*Refer to NFPA 220 for more information about Type I and Type II building construction.
**No additional NEC article 450.23 safeguards are required if one or more of exceptions 1-6 of Section 450.26, Oil-insulated transformers installed indoors apply.

2017 Code Options for the Installation of Listed Less-Flammable Liquid-Filled Transformers

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Reference Data TD900001EN
Effective January 2019

Listing option ­ A
Underwriters Laboratories Requirements*
The UL Classification of less-flammable liquids per the NEC Section 450.23 for 3-Phase 45-10,000 kVA transformers requires:
· Transformers be equipped with tanks capable of withstanding 12 psig without rupture.
· Transformers be equipped with pressure relief devices with minimum pressure relief capacity per the UL Classification Marking.
· Transformer primaries be protected with overcurrent protection options per the UL Classification Marking.
Overcurrent Protection Option I, available exclusively with Envirotemp FR3 Fluid's UL Classification, allows internal expulsion fuses (e.g. bay-o-net fuses) only if in series with current limiting fuses. Overcurrent Protection Option II allows stand-alone expulsion fuses, but they must be located o utside the transformer tank.
To specify a UL Classified Envirotemp FR3 fluid-filled transformer for a specific kVA rating, refer to the UL Classification Marking for the fluid shown in Table 3.

Table3. UL Classification Marking for Envirotemp FR3 Fluid (EOVK.MH10678)
"Envirotemp® FR3." Classed 4 to 5 less hazardous than paraffin oil with respect to fire hazard. Flash point (closed cup) 255°C (491°F). Fire point 358°C (676°F). Ignition temperature 428°C (802°F). Also Classified as a "less-flammable liquid" as specified in the National Electric Code when used in 3-phase transformers, 45 through 10,000 kVA with the following "use restrictions":
A. F or use only in 3-phase transformers having tanks capable of withstanding an internal pressure of 12 psig without rupture.
B. R equired use of pressure relief devices on transformer tank in accordance with the following tabulation to limit internal pressure buildup and prevent tank rupture due to gas generation under low current arcing faults, and
C. R equired use of current limiting fusing in the transformer primary having I2t characteristics not exceeding the values in the following tabulation. Underfluid expulsion fuses may be used in series with the current-limiting fuses, in accordance with the manufacturer's protection scheme, or
D. R equired use of overcurrent protection in the transformer primary having I2t characteristics not exceeding the values in the following tabulation. If the fuse is designed to vent during operation (such as an expulsion fuse), it shall be located external to the transformer tank.

* UL EOVK - Transformer Fluids

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Transformer 3-Phase Transformer Rating kVA
45

Required Protection

Required Prc

Required Current Limiting Fusing (+) Maximum I2t (A2s)

Or Required Overcurrent Protection (+) Maximum I2t (A2s)

Minimum Required Pressure Relief Capacity, (++) SCFM at 15 psi

500,000

700,000

35

75

500,000

800,000

35

112.5

550,000

900,000

35

150

600,000

1,000,000

50

225

650,000

1,200,000

100

300

750,000

1,400,000

100

500

900,000

1,900,000

350

750

1,100,000

2,200,000

350

1,000

1,250,000

3,400,000

350

1,500

1,500,000

4,500,000

700

2,000

1,750,000

6,000,000

700

2,500

2,000,000

7,500,000

5,000

3,000

2,250,000

9,000,000

5,000

3,750

2,500,000

11,000,000

5,000

5,000

3,000,000

14,000,000

5,000

7,500

3,000,000

14,000,000

5,000

10,000

3,000,000

14,000,000

5,000

(+) T his is an additional requirement to the overcurrent protection required in accordance with Section 450.3 of the current National Electrical Code®.
(++) Opening pressure, 10 psig maximum.

2017 Code Options for the Installation of Listed Less-Flammable Liquid-Filled Transformers

Reference Data TD900001EN
Effective January 2019
Fire protection for indoor transformers (FM requirement)
If transformers cannot be located outdoors in accordance with section 2.3 of the FM DS 5-4, provide a detached dedicated building or room with location and construction safeguards as described in Fig. 1 and Table 1 (Reference to Fig. 2a and Table 4 of the FM DS 5-4). This applies to dry or liquid filled insulated transformers.

Fig 1. Locations from Transformer buildings and rooms* Table 4. Recommended construction for transformer buildings and rooms**

Transformer type Dry or gas insulateda FM approved or equivalentc

Fluid type Not applicable FM approved liquid FM approved liquids
Non approved liquids

Fluid volume in largest transformer Not applicable Anyd Anyd
Less than 100 gal (380 L)d
More than 100 gal (380 L)d

Room or building fire rating Non combustible Non combustible One-hour fire-rated Non combustible One-hour fire-rated

Fire protection for transformer liquids Noneb
Noneb
Noneb Per section 2.2.3e Noneb

Three-hour fire-rated with subdivisions if multiple transformersf
Three-hour fire-rated with multiple transformers and no subdivision
One-hour fire-rated with single transformer

Noneb Per section 2.2.3e Per section 2.2.3e

a With no oil-filled bushings, oil-filled tap changer or other oil-filled accessories that could increase the fire hazard
b See also Section 2.2.3.4 for protection of combustibles other than transformer liquids
c Section 3.3 describes FM approved and equivalent transformers
d Provide liquid spill containment in accordance with section 2.2.1.5
e Automatic sprinklers, foam-water sprinklers or water mist. Also provide emergency drainage for sprinklers discharge per Section 2.2.1.6
f Subdivide room or building with three-hour fire-rated construction for each transformer if multiple transformers are present

* Fig. 1 is based on the information provided on Fig. 2a of the FM document DS 5-4 dated 10-2017. ** Table 4 is based on the information provided on Table 4 of the FM document DS 5-4 dated 10-2017.

2017 Code Options for the Installation of Listed Less-Flammable Liquid-Filled Transformers

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Reference Data TD900001EN
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Listing option - B
FM Global Requirements

The FM indoor installation requirements for all transformer and fluid types are given in FM Global Property Loss Prevention Data Sheets 5-4 - Transformers (LPD). Specific requirements for lessflammable liquid-insulated transformers are included. Refer to Section 2.2.1.2 of FM LPD for special installation requirements for network transformers.
General transformer requirements are as follows:
· Minimum 3 ft. clear from building walls, and
· Liquid containment provisions, and
· Room fire resistance rating based on fluid and transformer type, and
· Room ventilation, if necessary, to prevent non-thermal damage, and
· Smoke detection with alarm in the electrical room.
Less-flammable liquid-filled transformers must comply with one of the following:
· Be FM Approved or equivalent,
Or · Be located in a room with a one hour fire resistance rating,
Or · Have automatic sprinklers above the transformer and 20 ft.
beyond with a discharge density of 0.20 gpm/sq. ft.
FM Approved Transformer:
Less-flammable liquid-filled transformers rated 5 through 10,000 kVA must be equipped with specific design and protection features to be FM Approved or equivalent. Key characteristics of this protection system are fire properties of the liquid, the ability to mechanically withstand pressure generated by a low level electrical fault and the ability of electrical p rotection to clear a fault before tank rupture.

According to FM Global Standard 3990 dated 1-2018, the key protection features are as listed below. Refer to the FM standard for complete requirements:
· The transformer tank rupture strength shall be a m inimum of 15 psig for rectangular and 20 psig for cylindrical tanks. All transformer tanks shall be designed to withstand a pressure of 7 psig without p ermanent distortion, And
· The transformer tank shall be provided with a p ressure relief device to vent internal over-pressures. The device must be capable of venting a minimum s pecified flow rate, based on the kVA as noted in Table 4 and Section 3.2.3 of the FM Global Standard 3990. Proper pressure venting coordinated with proper tank pressure withstand rating has proven highly effective in preventing tank rupture from overpressure due to internal fault currents below the trip rating of primary circuit current limiting fuses, And
· The unit is filled with an FM Global Less-Flammable liquid* to reduce the probability of ignition of the liquid. Less-Flammable liquids, also known as high fire point or fire resistant liquids, are dielectric coolants that have a minimum fire point of 300 °C per the ASTM D92 Open Cup Test Method, And
· The primary circuit shall have over-current protection which limits the let-through current (I2t) to a specified maximum value as listed in Table 5 and in Section 3.2.5 of the FM Global Standard 3990. Current-limiting fusing and its functional equivalents are designed to interrupt a high current internal fault before the tank withstand pressure level is reached. If protection is designed to vent gas during operation, such as with expulsion fuses, this protection shall be located outside the transformer tank. Exception: E nvirotemp FR3 fluidimmersed expulsion fusing (e.g. bay-o-net) may be mounted in the transformer tank if in series and properly coordinated with current limiting fusing, And
· The transformer shall have an additional nameplate with the FM Global mark with the following data: tank pressure rating, fuse part number, pressure relief device part number, and requirements particular to the type of installation.

* For a listing of FM Global Less-Flammable liquids, refer to the Less Flammable Fluids section of the FM Global Approval Guide - Electrical Equipment.

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Reference Data TD900001EN
Effective January 2019

Listing option - B
FM Global Requirements (continued)

· For grounded wye secondary windings of 150 volts or more and rated at 1,000 or more nominal amperes, a n otification tag shall be provided by the manufacturer, secured to the low voltage neutral bushing, advising that the transformer installation requires ground fault relay protection prior to energization (if not installed at time of manufacturing), Indoor units greater than 500 kVA should be provided with alarm contacts on the pressure relief device and units greater than 2500 kVA, in all locations shall be equipped with alarm contacts on the pressure relief device and a rapid-rise relay, And
· Three-phase pad-mounted and substation transformers shall be equipped with an oil level gauge. Additionally, all transformers rated 750 kVA or higher shall be equipped with a liquid temperature indicator and pressure-vacuum gauge, And
· Transformers shall be capable of passing Basic Lightning Impulse Insulation Level (BIL) testing at a minimum tilt of 15° from vertical.
Table 5: FM Pressure Relief Device Required Ratings

kVA Rating 3-Phase (1-Phase) 112.5 (37.5) 150 (50) 300 (100) 1,000 (333) 2,000 (667) 10,000 (3,333) Over 10000 KVA (3333 1Ø)

Flow Rate SCFM @ 15psi (103 pKa) 35 50 100 350 700 5,000 12600

NNote: For kVA ratings not listed use next highest rating in table.

Table6. FM Maximum I2t Let Through Required Ratings

kVA Rating 3-Phase (1-Phase) 45 (15) 75 (25) 112.5 (37.5) 150 (50) 225 (75) 300 (100) 500 (167) 750 (250) 1,000 (333) 1,500 (500) 2,000 (667) 2,500 (833) 3,000 (1,000) 3,750 (1,250) 5,000 (1,667) 7,500 (2,500) 10,000 (3,333) and over

Current Limiting Fusing 500,000 500,000 550,000 600,000 650,000 750,000 900,000 1,100,000 1,250,000 1,500,000 1,750,000 2,000,000 2,250,000 2,500,000 3,000,000 3,000,000 3,000,000

Other Protection
700,000 800,000 900,000 1,000,000 1,200,000 1,400,000 1,900,000 2,200,000 3,400,000 4,500,000 6,000,000 7,500,000 9,000,000 11,000,000 14,000,000 14,000,000 14,000,000

NNote: For kVA ratings not listed use next lowest rating in table.

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NEC Options for Transformer Listing Outdoor installations
The NEC allows two different options for the listing of the installed liquid transformers:
(A) Underwriters Laboratories; or
(B) FM Global
For outdoor installations, the FM approval indicates that the Spill containment requirements for environmental protection and related regulations are outside the scope of the DS 5-4. Some considerations can still be consider for spillage.
1. If an accidental release of transformer fluid could expose a main building or adjacent equipment or storage, provide the liquid filled transformer with a spill containment
2. Design the spill containment system in accordance with Chapter 7 of IEEE STD 980.
Or
It must be installed in accordance with NEC section 450.27, oil insulated transformers installed outdoors, i.e. space separation, fire barriers or water spray systems
Less-flammable liquid-insulated transformers are permitted to be installed outdoors, attached to, on, or adjacent to non-combustible* buildings. The installation must comply with the requirements of a recognized listing of the fluid.

A fine print note states that combustible material**, combustible buildings, fire escapes and door and window openings may require additional safeguarding, as describe in Section 450.27. Fine Print Notes (FNP) are defined in Section 90.5 as informational only and are not enforceable as code requirements

*Refer to NFPA 220 for definition of non-combustible or limited combustible Type I and II building construction. **Per NFPA 220, the definition of cumbustible material refers to material not classified as non-combustible or limited-combustible.

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Reference Data TD900001EN
Effective January 2019

Listing option - A
Underwriters Laboratories Requirements

Listing option - B
FM Global Requirements

The same UL Classification of less-flammable liquids per the NEC Section 450.23 for 3-Phase 45-10,000 kVA transformers applies to both indoor and outdoor applications and requires:
· Transformers be equipped with tanks capable of withstanding 12 psig without rupture, And
· Transformers be equipped with pressure relief devices with minimum pressure relief capacity per the UL Classification Marking, And
· Transformer primaries be protected with overcurrent protection options per the UL Classification Marking.
Overcurrent Protection Option I, available exclusively with Envirotemp FR3 Fluid's UL Classification, allows internal expulsion fuses (e.g. bay-o-net fuses) in series with current limiting fuses. Overcurrent Protection Option II allows standalone expulsion fuses, but they must be located outside the transformer tank.
To specify a UL Classified Envirotemp FR3 fluid-filled transformer for a specific kVA rating, refer to the UL Classification Marking for the fluid shown in Table 3.

The outdoor installation requirements according to FM Global Property Loss Prevention Data Sheets 5-4 - Transformers consist of requirements for transformer and fluid types. Specific requirements for less-flammable liquid-insulated transformers are included.
FM outdoor installation requirements are based on the FM Approval Status of the transformer and both the volume and FM Approval Status of the fluid. If transformers filled with conventional mineral oil or non-approved fluids would expose buildings and equipment to a release of oil, the transformer must comply with FM LPD requirements. This may include containment, separation distances, fire barriers, or water spray systems. Installation of FM Approved transformers or transformers with FM Approved less-flammable liquids must comply with FM LPD requirements for containment and separation distances. The FM LPD provides detailed requirements for fire barriers in Section 2.3.1.1.1 and water spray exposure protection in Section 2.3.2.1.
Fluid containment requirements as detailed in Section 2.3.1.4 of the FM LPD are:
· Provide a liquid containment when accidental release of fluid could expose the main building, adjacent equipment or storage
· Design the containment per IEEE 980
· Where water spray is provided, install additional containment or direct discharge water, this per DS 7-83
· Provide system for removal of rainwater from the containment area
· Extend containment perimeter at least 5 ft for transformers with up to 1000 gal and 8 ft for transformers with more than 1000 gal
· Provide containment system for roof-mounted liquid-filled transformer

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Reference Data TD900001EN
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Listing option - B
FM Global Requirements (continued)
Separation Distance: Separation distance requirements are based on whether the transformer is FM Approved or equivalent, or the volume of fluid, and if the fluid is FM Approved. For FM listed less-flammable liquid as well as the non-approved FM transformer, the horizontal distance is measured from closest inside edge of the spill containment barrier area and the 2 hour fire barrier.
Per Approval standard 3990 dated 1-2018, the transformer must be located 5 ft (1.5 m) from doors, fire escapes and windows

Fig 2. Minimum horizontal sepration distance between outdoor liquid insulated transformer and exposed walls of main building*

Table 7. Separation for exposure protection of main building walls (see Fig. 2) **

Fluid or transformer type

Fluid volume, gal (m3)

Minimum horizontal distance from containment to expose building wall (dimension X in fig 2)

Non-combustible wall 1 2-hour fire-rated wall ft (m) ft (m)

Combustible wall 1 ft (m)

FM approved transformer or equivalent

Per approval listing

3 (0.9)

3 (0.9)

3 (0.9)

FM approved liquid in non-approved < 10,000 (38)

transformer

>10,000 (3.8)

5 (1.5) 5 (1.5)

5 (1.5) 5 (1.5)

25 (7.6) 50 (15.2)

<500 (1.9)

5 (1.5)

15 (4.6)

25 (7.6)

Non-approved transformer liquid

<5000 (1.9 ­ 19)

15 (4.6)

25 (7.6)

50 (15.2)

>5000 (19)

25 (7.6)

50 (15.2)

100 (30.5)

1 For definition of combustible and non-combustible construction material, see Appendix A of DS 1-1. Fire safe building construction and materials

* Figure 2 is based on the information provided on Fig. 2b of the FM document DS 5-4 dated 10-2017. ** Table 7 is based on the information provided on Table 5 of the FM document DS 5-4 dated 10-2017.

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Listing option - B
FM Global Requirements (continued)

Reference Data TD900001EN
Effective January 2019

Fig 3. Use of 2-hour fire barriers and separation distances for protection of exposed main building walls*

Table 8. Separation and extent of 2-hour fire barrier for protection of Main building walls (for dimensions refer to fig. 3) **

Fluid type

Fluid volume, gal (m3)

Separation and extent of 2-hour fire barrier

Dimensions 1,2 (See fig. 3)

Non-combustible wall 3 ft (m)

Combustible wall 3 ft (m)

X

5 (1.5)

5 (1.5)

< 10,000 (38)

Y

5 (1.5)

25 (7.6)

FM approved transformer fluid

Z

25 (7.6)

25 (7.6)

X

15 (4.6)

15 (4.6)

>10,000 (3.8)

Y

15 (4.6)

50 (15.2)

Z

50 (15.2)

50 (15.2)

X

5 (1.5)

5 (1.5)

<500 (1.9)

Y

15 (4.6)

25 (7.6)

Z

25 (7.6)

25 (7.6)

X

Non-approved transformer liquid

5000 (1.9 ­ 19)

Y

Z

15 (4.6) 25 (7.6) 50 (15.2)

15 (4.6) 50 (15.2) 50 (15.2)

X

25 (7.6)

25 (7.6)

>5000 (19)

Y

50 (15.2)

100 (30.5)

Z

100 (30.5)

100 (30.5)

1 For definition of combustible and non-combustible construction material, see Appendix A of DS 1-1. Fire safe building construction and materials

2 Barrier vertical extent is dimension Z in the Table of the building height plus 30 in. (0.75 m) parapet, whichever is less.

3 For definitions of combustible and non-combustible construction material, see Appendix A of DS 1-1, Fire Building Construction and Materials

* Figure 3 is based on the information provided on Fig. 2c of the FM document DS 5-4 dated 10-2017. ** Table 8 is based on the information provided on Table 6 of the FM document DS 5-4 dated 10-2017.

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Reference Data TD900001EN
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Listing option - B
FM Global Requirements (continued)

Fig 4. Determination of exposed roof area*

Table 9. Transformer fire exposure to non-combustible building roof where separation from wall is based on 3-hour fire barrier or water spray protection **

Liquid type Non-approved transformer fluid

Maximum liquid volume Gal (m3) <1000 (3.8) Any 1000 ­ 5000 (3.8 ­ 19) 1000 ­ 5000 (3.8 ­ 19) >5000 (19)

Building height ft (m) Any 50 (15) 25 (7.5) <25 (7.5) <50 (15)

W (see fig. 4) ft (m) Not exposed Not exposed Not exposed 15 (4.5) 25 (7.5)

Table 10. Minimum separation distance between adjacent transformers

Liquid type FM approved transformer fluid
Non-approved transformer fluid

FM Approved transformer or Equivalent Yes No No N/A N/A N/A

Liquid Volume gal (m3) N/A <10000 (38) >10000 (38) <500 (1.9) 500 - <5000 (19) >5000 (19)

Distance ft (m) 3 (0.9) 5 (1.5) 25 (7.6) 5 (1.5) 25 (7.6) 50 (15.2)

* Figure 4 is based on the information provided on Fig. 2d of the FM document DS 5-4 dated 10-2017. ** Table 9 is based on the information provided on Table 7 of the FM document DS 5-4 dated 10-2017.

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Outdoors on or adjacent to combustible buildings or combustible materials
Installation type
For installations other than Type I and Type II* buildings or for installations that do not comply with all the restrictions provided for in the listing of the liquid.
NEC requirement
· Per NEC Section 450.27, Oil-Insulated Transformers Installed Outdoors.
Section 450.23 refers to Section 450.27, Oil Insulated Transformers Outdoors, for installation requirements when lessflammable liquid-filled transformers are installed on or adjacent to combustible buildings or near combustible materials. As for conventional oil-filled transformers, it requires the safeguarding of combustible material, combustible buildings, fire escapes and door and window openings. Recognized safeguards include space separation, fire barriers, spray extinguishing systems and confinement areas for spilled fluid. The NEC requires that one or more of the above safeguards be applied according to the degree of fire hazard p resent in cases where the installation presents a fire hazard. Obviously, less-flammable liquid-filled transformers significantly reduce the possibility that the installation presents a fire hazard compared to c onventional mineral oil.

Reference Data TD900001EN
Effective January 2019

*Refer to NFPA 220 for definition of non-combustible or limited combustible Type I and II building construction.

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Appendix 1 - Indoor installations per UL listing requirements
Less-Flammable Liquid-Insulated Transformers Compliance to NEC Section 450.23 per UL Listing Requirement Highlights

Reference Data TD900001EN
Effective January 2019

Transformer  35 kV and Liquid Confinement Area Available Yes
Non-Combustible Building (Type I or Type II)* and
No Combustibles in the Area Yes
UL Classified Transformer Fluid**
Yes

No No No

Automatic Fire

Extinguishing

No

System Available

Yes Yes

In Accordance with One or More of the Exceptions of NEC
450.26

No

Installation Incorporates UL Classification** Marking
Requirements
Yes or

No or

Vault Requirements Per NEC 450, Part III

UL OPTION I · Pressure Relief Device ·M inimum 12 psig Tank Pressure
Rupture Withstand ·P rimary Current Limiting Fusing
Per UL Classification Marking.**
Yes

UL OPTION II · Pressure Relief Device ·M inimum 12 psig Tank Pressure Rupture
Withstand ·O vercurrent Protection Per UL Classification
Marking.** NOTE: Devices that vent during operation such as bay-o-net fuses may not be liquid-immersed.
Yes

NEC Code Requirements UL Listing Requirements

COMPLIANCE WITH
NEC 450.23

UL Classified Transformer Fluids:** Cargill Envirotemp FR3 Fluid (natural ester), Option I or Option II Dow Corning® 561 (silicone), Option II only

* Refer to NFPA 220 for definition of non-combustible Type I and II building construction ** Transformer Fluids (EOVK), Underwriters Laboratories Certifications Directory

NNote: UL Classification Dielectric Mediums (EOUV) states that "Liquids intended for use as dielectric and cooling mediums in electrical transformers are covered under Transformer Fluids (EOVK).

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Reference Data TD900001EN
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Appendix 2 - Outdoor installations per UL listing requirements
Less-Flammable Liquid-Insulated Transformers Compliance to NEC Section 450.23 per UL Listing Requirement Highlights

Non-Combustible Building

(Type I or Type II)* and

No

No Combustibles in the Area

Yes

UL Classified Less-Flammable Liquid**

No

Yes

Installation Incorporates UL

Classification** Marking

No

Requirements

or

or

Requirements Per NEC 450.27 If installation presents fire hazard one or more of the following safeguards shall be applied: · Space Separation · Fire Barriers · Automatic Water Spray · Enclosure
Yes

UL OPTION I · Pressure Relief Device ·M inimum 12 psig Tank Pressure
Rupture Withstand ·P rimary Current Limiting Fusing
Per UL Classification Marking.**
Yes
NEC Code Requirements UL Listing Requirements

UL OPTION II · Pressure Relief Device ·M inimum 12 psig Tank Pressure Rupture
Withstand ·Overcurrent Protection
Per UL Classification Marking.** NOTE: Devices that vent during operation such as bay-o-net fuses may not be liquidimmersed.
Yes

COMPLIANCE WITH
NEC 450.23

UL Classified Transformer Fluids:* Cargill Envirotemp FR3 Fluid (natural ester), Option I or Option II Dow Corning® 561 (silicone), Option II only
* R efer to NFPA 220 for definition of non-combustible Type I and II building construction
** Transformer Fluids (EOVK), Underwriters Laboratories Certifications Directory
NNote: UL Classification Dielectric Mediums (EOUV) states that "Liquids intended for use as dielectric and cooling mediums in electrical transformers are covered under Transformer Fluids (EOVK)."

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Reference Data TD900001EN
Effective January 2019

Appendix 3

UL Classified Less-Flammable Liquids & UL Listed & Classified Transformers
Important Information to Assure Code Compliance Part A: Dielectric liquids
Not all UL Classified dielectric liquids applied in transformers meet NEC Section 450.23 requirements.
Simply specifying that a transformer be filled with a UL Classified dielectric liquid is not sufficient to assure the transformer meets NEC Section 450.23 listing requirements.
UL has two classification categories for dielectric liquids: · EOUV: Dielectric Mediums (See page 24 for EOUV.guideinfo)
· EOVK: Transformer Fluids (See page 26 for EOVK.guideinfo)
To assure compliance with NEC Section 450.23 listing requirements of UL, the dielectric liquid must be Classified as an EOVK Transformer Fluid as detailed in Part A2 of this appendix.
Part A1: UL Classification EOUV Dielectric Mediums This category is a fire hazard rating only. All Classified Dielectric Mediums have the same fire hazard ratings, "Classed 4 to 5 less hazardous paraffin oil in respect to fire hazard". Included in the EOUV Classification are requirements for minimum ignition temperature, fire point, and closed cup flash point. This Classification makes no reference to NEC 450.23, and does not classify the fluid as a "less-flammable liquid" in accordance with Section 450.23.

Table A1 - UL Classified EOUV Dielectric Mediums

EOUV Dielectric Medium

Type

Cargill Incorporated Envirotemp FR3

natural ester

Momentive Performance Materials SF97-50 Sopus Products Diala® HFX DSI Ventures Beta®

silicone HMWH HMWH

Dielectricos Vegatales SAS

Natural Ester

Dong Nam Petroleum Ind. Co Ltd

Natural Ester

Dow Silicone Co Ltd

silicone

Dow Silicone Corp

silicone

M&I Materials Ltd

Synthetic Ester

Prolec GE International SRL de CV

Natural Ester

Savita Polymer Limited

Natural Ester

Yi Chiu Chemical & Technical Co Ltd

Insulating Oil

This category covers liquids intended for use as dielectric and cooling mediums. Liquids intended for use as dielectric and cooling mediums in electrical transformers are covered under Transformer Fluids (EOVK).

Part A2: UL Classification EOVK Transformer Fluids

In addition to giving the requirements for minimum ignition temperature, fire point, and closed cup flash point, this category gives the UL Use Restrictions required for compliance with NEC 450.23 for the listed less flammable fluids.
Table A2 gives the fluids listed in the UL Directory having EOVK Classification.
Table A2 - UL Classified EOVK Transformer Fluids

EOVK Transformer Fluids

Type

Cargill Incorporated Envirotemp FR3 fluid

natural ester

Dow Corning 561

silicone

This category covers liquids intended for use as dielectric and cooling mediums in electrical transformers.

 This list includes all the insulating liquid manufacturers listed by UL and FM Global as of the date of this publication. Refer to UL and FM Global for the latest lists.

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Reference Data TD900001EN
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Appendix 3 (continued)

UL Classified Less-Flammable Liquids & UL Listed & Classified Transformers
Important Information to Assure Code Compliance Part B: UL Listed Transformers
Not all UL Listed and classified transformers meet NEC Section 450.23 requirements.
Simply specifying that a transformer be UL Listed is not sufficient to assure the transformers meet NEC Section 450-23 listing requirements.
To assure UL Listed transformers meet NEC Section 450-23 requirements, the transformer must use an EOVK Transformer Fluid or EOUV dielectric medium and meet its Use Restrictions (see Part A2).
Part B1: XPLH Transformers, Distribution, Liquid-filled Type, Over 600 Volts
UL transformer listing requirements, detailed in UL GuideInfo XPLH, allow the use of mineral oil and other transformer coolants regardless of Classification status. These transformers are required to comply with various IEEE C57.12.00 standards listed in the XPLH.GuideInfo sheet. This guide states that transformers with the UL Listing mark are: "intended for installations with the requirements of NFPA 70, National Electrical Code". Table B1 shows the manufacturers of UL Listed liquid-insulated transformers.

Table B1 - UL XPLH Listed Transformers
XPLH Transformer Manufacturers EATON Cooper Power Series ABB Inc, South Boston VA ABB Inc, Jefferson City MO GE Co., Shreveport LA Howard Industries Inc, Laurel, MS Prolec GE, Monterrey MX Virginia Transformer Corp, Roanoke VA ERMCO, Dyersburg, TN Maddox Industrial Transformer LLC, Mauldin, SC Niagara Transformer Corp., Buffalo, NY Schneider Electric USA, Nashville, TN Siemens Energy INC, Richland, MS Solomon Corporation, Solomon, KS Southwest Electric, Oklahoma City, OK Sunbelt Transformer INC, Temple, TX Vantran Industries INC, Waco, TX HC Transformer and Switchgear, Torrance, CA WEG Transformers USA, Washington, MO
These transformers will display a single UL Listing Mark, the UL symbol, together with the word "LISTED," a control number, and the product name "Liquid-Filled Distribution Transformer" as in Figure B1.

LISTED XPLH.E234598 LiquidFilled Distribution Xfmr
Figure B1 ­ Example transformer mark for a UL Listed ANSI-compliant transformer.

 This list includes all the insulating liquid manufacturers listed by UL and FM Global as of the date of this publication. Refer to UL and FM Global for the latest lists.

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Appendix 3 (continued)

Reference Data TD900001EN
Effective January 2019

UL Classified Less-Flammable Liquids & UL Listed & Classified Transformers
Important Information to Assure Code Compliance Part A: Dielectric Coolants
Part B2: UL Listed and Classified Transformers for use as LessFlammable Liquid-Insulated Transformer In Accordance With Sec. 450.23 of the NEC **
UL uses the same XPLH GuideInfo sheet noted above for transformers intended to meet the requirements of NEC section 450.23. However, the sub-header "USE AND INSTALLATION" adds the following requirements:
· Transformer must be provided with UL Classified "LessFlammable Liquid, having a fire point of not less than 300°C"
· Transformer must be Marked to:
· identify the product name and flammability rating of the liquid
· indicate whether the liquid may evolve flammable gases when decomposed by an electric arc (as applicable)
· list all the use restrictions provided for in the UL Classification of the liquid.
A UL Listed and Classified Transformer must display both a Listing mark and a Classification mark. See Figure B2.

LISTED XPLH.E234598 Liquid-Filled Distribution Xfmr
ALSO CLASSIFIED FOR USE AS LESSFLAMMABLE LIQUID-INSULATED TRANSFORMER IN ACCORDANCE WITH SEC. 450-23 OF THE NATIONAL ELECTRICAL CODE (NEC) AND MARKED USE RESTRICTIONS ON THE TRANSFORMER
Figure B2 Example transformer mark for a UL Listed and Classified transformer filled with an UL EOVK Transformer Fluid and complying with its Use Requirements.
Eaton manufacturers UL Listed and Classified Transformers for use as less-flammable liquid-insulated transformers in accordance with NEC Section 450.23. UL does not currently publish which transformer manufacturers offer the dual marking. Purchasers and users should confirm their UL Listed transformers also are UL Classified and the units have both respective UL logos for units that are intended for use in complying with NEC Section 450.23.
The transformer listing by UL should be referred to as an "UL Listed And Classified Transformer for Use as Less-Flammable Liquid-Insulated Transformer in Accordance with Sec. 450.23 of The National Electric Code (NEC)".

** The source of the information of this section is the UL online certification Directory, XPHL.GuideInfo -Transformers, Distribution, Liquid-filled Type, Over 600 Volts on October 18, 2016. Copyright © Underwriters Laboratories Inc®.

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Reference Data TD900001EN
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Appendix 3 (continued)

UL Classified Less-Flammable Liquids & UL Listed & Classified Transformers

Important Information to Assure Code Compliance EOUV.GuideInfo Dielectric Mediums USE

This category covers liquids intended for use as dielectric and cooling mediums. The liquids are not intended to replace mineral oil unless equipment is also designed for the specific liquid.
These products have been Certified as to their fire hazard only, using Underwriters Laboratories' method for Classification of the fire hazard of liquids. They have been rated on a numerical scale of hazard ranging from 0 to 100 as indicated in the table below:

General classification Diethyl ether Gassoline Between gasoline and ethyl alcohol Between ethyl alcohol and gasoline Ethyl alcohol Between ethyl alcohol and kerosene Between kerosene and ethyl alcohol Kerosene Between kerosene and paraffin oil Paraffin oil Less hazardous than paraffin oil Water or nonflammable

Numerical classification 100 90 to 100 80 to 90 70 to 80 60 to 70 50 to 60 40 to 50 30 to 40 20 to 30 10 to 20 0 to 10 0 or nonflammable

NNote: Dielectric media/transformer fluids including mineral oil, natural and synthetic esters, silicone oil and refined petroleum oil exhibiting flammability temperature limits > 464°F (240°C) may be assigned a Numerical Fire Hazard Rating of "4-5 Less Hazardous than paraffin oil."

Related products Liquids intended for use as dielectric and cooling mediums in electrical transformers are covered under Transformer Fluids (EOVK).
Additional information For additional information, see Electrical Equipment for Use in Ordinary Locations (AALZ) and Flammable and Combustible Liquids and Gases Equipment (AAPQ).
Requirements The basic standard used to investigate products in this category is ANSI/UL 340 "Tests for Comparative Flammability of Liquids."
UL Mark The Certification Mark of Underwriters Laboratories Inc. on the product container is the only method provided by UL to identify products manufactured under its Classification and Follow-Up Service. The Certification Mark for these products includes the UL symbol, the word ""CERTIFIED" and "SAFETY", the geographical identifier(s) and the file number.
Additional Certification Markings
Products covered under this category are additionally marked with the following information:
AS TO FIRE HAZARD ONLY
These products may also be marked with the following statement:
MAY EVOLVE FLAMMABLE GASES WHEN DECOMPOSED BY AN ELECTRIC ARC
Alternate UL Mark
The Classification Mark of UL on the product container is the only method provided by UL to identify products manufactured under its Classification and Follow-Up Service. The Classification Mark for these products includes the UL symbol, the word "CLASSIFIED" above the UL symbol (as illustrated in the Introduction of this Directory), and the following additional information:

[PRODUCT IDENTITY] CLASSED ____ AS TO FIRE HAZARD ONLY Control No.

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Appendix 3 (continued)
UL Classified Less-Flammable Liquids & UL Listed & Classified Transformers
Important Information to Assure Code Compliance EOUV.GuideInfo Dielectric Mediums USE
The Classification Mark may also include the following statement as appropriate:
MAY EVOLVE FLAMMABLE GASES WHEN DECOMPOSED BY AN ELECTRIC ARC
UL, in performing its function in accordance with its objectives, does not assume or undertake to discharge any responsibility of the manufacturer or any other party. UL shall not incur any obligation or liability for any loss, expense or damages, including incidental or consequential damages, arising out of or in connection with the use, interpretation of, or reliance upon this Guide information
Last Updated on 2017-08-28
Notice of Disclaimer
The appearance of a company's name or product in this database does not in itself assure that products so identified have been manufactured under UL's Follow-Up Service. Only those products bearing the UL Mark should be considered to be Certified and covered under UL's Follow-Up Service. Always look for the Mark on the product.
UL permits the reproduction of the material contained in the Online Certification Directory subject to the following conditions:
The Guide Information, Assemblies, Constructions, Designs, Systems, and/or Certifications (files) must be presented in their entirety and in a non-misleading manner, without any manipulation of the data (or drawings). 2. The statement "Reprinted from the Online Certifications Directory with permission from UL" must appear adjacent to the extracted material. In addition, the reprinted material must include a copyright notice in the following format: "© 2018 UL LLC".
The source of the information of this section is the UL online certification Directory,
http://productspec.ul.com/document.php?id=EOUV.GuideInfo

Reference Data TD900001EN
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Appendix 3 (continued)

UL Classified Less-Flammable Liquids & UL Listed & Classified Transformers

Related products
Liquids intended for use as dielectric and cooling mediums are covered under Dielectric Mediums (EOUV).

Important Information to Assure Code Compliance EOVK.GuideInfo Transformer Fluids (Dielectric Mediums) Transformer Fluids USE

This category covers liquids intended for use as dielectric and cooling mediums in electrical transformers.
These products have been Certified as to their fire hazard only, using Underwriters Laboratories' method for Classification of the fire hazard of liquids. They have been rated on a numerical scale of hazard ranging from 0 to 100 as indicated in the table below:

General classification Diethyl ether Gassoline Between gasoline and ethyl alcohol Between ethyl alcohol and gasoline

Numerical classification 100 90 to 100 80 to 90 70 to 80

Use restrictions
Products Classified as "less-flammable liquid" may have use restrictions on the product container. Certain fluids have fuse use restrictions which require that the fuse must be either a type which does not vent under normal operation, or it must be installed external to the transformer tank.
Additional information
For additional information, see Electrical Equipment for Use in Ordinary Locations (AALZ) and Flammable and Combustible Liquids and Gases Equipment (AAPQ).
Requirements
The basic standard used to investigate products in this category is ANSI/UL 340 "Tests for Comparative Flammability of Liquids."
These products are also certified as a "less-flammable liquid" or "nonflammable liquid" in accordance with Sections 450.23 or 450.24 of ANSI/NFPA 70, "National Electrical Code."

Ethyl alcohol Between ethyl alcohol and kerosene Between kerosene and ethyl alcohol Kerosene Between kerosene and paraffin oil Paraffin oil

60 to 70 50 to 60 40 to 50 30 to 40 20 to 30 10 to 20

UL mark
The Certification Mark of Underwriters Laboratories Inc. on the product container is the only method provided by UL to identify products manufactured under its Certification and Follow-Up Service. The Certification Mark for these products includes the UL symbol, the word "CERTIFIED" and "SAFETY", the geographical identifier(s) and a file number.

Less hazardous than paraffin oil

0 to 10

Additional Certification Markings

Water or nonflammable

0 or nonflammable

Products covered under this category are additionally marked with the following information:

NNote: Dielectric media/transformer fluids including mineral oil, natural and synthetic esters, silicone oil and refined petroleum oil exhibiting flammability temperature limits > 464°F (240°C) may be assigned a Numerical Fire Hazard Rating of "4-5 Less Hazardous than paraffin oil."

AS TO FIRE HAZARD ONLY
These products may also be marked with one or more of the following statements:
MAY EVOLVE FLAMMABLE GASES WHEN DECOMPOSED BY AN ELECTRIC ARC

ALSO CERTIFIED AS A "LESS-FLAMMABLE LIQUID" IN COMPLIANCE WITH THE NATIONAL ELECTRICAL CODE

WITH "USE RESTRICTIONS"

ALSO CERTIFIED AS A "NONFLAMMABLE LIQUID" IN COMPLIANCE WITH THE NATIONAL ELECTRICAL CODE WITH "USE RESTRICTIONS"

Alternate UL Mark

The Classification Mark of UL on the product container is the only method provided by UL to identify products manufactured under its Classification and Follow-Up Service. The Classification Mark for these products includes the UL symbol, the word "CLASSIFIED" above the UL symbol (as illustrated in the Introduction of this Directory), and the following additional information:

For the original info see the following link http://productspec. ul.com/document.php?id=EOvk.GuideInfo

[PRODUCT IDENTITY] CLASSED ____ AS TO FIRE HAZARD ONLY Control No.

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Appendix 3 (continued)
UL Classified Less-Flammable Liquids & UL Listed & Classified Transformers
Important Information to Assure Code Compliance EOVK.GuideInfo Transformer Fluids (Dielectric Mediums) Transformer Fluids USE
The Classification Mark may also include the following statement as appropriate:
MAY EVOLVE FLAMMABLE GASES WHEN DECOMPOSED BY AN ELECTRIC ARC
Also classified as a "less-flammable liquid"
In compliance with the national electrical code
With the following "use restrictions"
Also classified as a "nonflammable liquid"
In compliance with the national electrical code
With the following "use restrictions"
UL, in performing its functions in accordance with its objectives, does not assume or undertake to discharge any responsibility of the manufacturer or any other party. UL shall not incur any obligation or liability for any loss, expense or damages, including incidental or consequential damages, arising out of or in connection with the use, interpretation of, or reliance upon this Guide Information.
Last Updated on 2017-08-28
Notice of Disclaimer The appearance of a company's name or product in this database does not in itself assure that products so identified have been manufactured under UL's Follow-Up Service. Only those products bearing the UL Mark should be considered to be Certified and covered under UL's Follow-Up Service. Always look for the Mark on the product.
UL permits the reproduction of the material contained in the Online Certification Directory subject to the following conditions:
The Guide Information, Assemblies, Constructions, Designs, Systems, and/or Certifications (files) must be presented in their entirety and in a non-misleading manner, without any manipulation of the data (or drawings). 2. The statement "Reprinted from the Online Certifications Directory with permission from UL" must appear adjacent to the extracted material. In addition, the reprinted material must include a copyright notice in the following format: "© 2018 UL LLC".
The source of the information of this section is the UL online certification Directory,
http://productspec.ul.com/document.php?id=EOvk.GuideInfo

Reference Data TD900001EN
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Reference Data TD900001EN
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Appendix 4 - Indoor installations per FM listing requirements
Less-Flammable Liquid-Insulated Transformers Compliance to NEC Section 450.23 per FM Listing Requirement Highlights

Transformer  35 kV and Liquid Confinement Area Available

No

Yes

Non-Combustible Building

(Type I or Type II)* and No

No

Combustibles in the Area

Automatic Fire

Extinguishing

No

System Available

Yes

Yes

FM Approved

Less-Flammable Liquid**

No

Yes

In Accordance With One

Yes

Or More of the

Exceptions of NEC

450.26

No

Installation Incorporates

No

FM LPD Sheet*** Requirements

Yes

Vault Requirements per NEC 450, Part III
Yes

FM Approved Transformer** or

Equivalent includes

a) Tank Rupture Strength

b) Tank Pressure Relief

Yes

c) Low Current Fault Protection

d) High Current Fault Protection

e) Approved Less-Flammable Liquid

COMPLIANCE WITH
NEC 450.23

NEC Code Requirements FM Listing Requirements

FM Approved Fluids include:  Cargill Envirotemp FR3 Fluid (natural ester) M&I Materials MIDEL® 7131 (synthetic ester) Shell Diala® HFX (fire resistant hydrocarbon)
Dow Chemical L-305, Y-7582 (silicone) DSI Alpha-1TM, Beta® (hydrocarbon) Dow Corning® 561 (silicone)
Momentive Performance Mat SF97-50
Prolec GE Int'l VG-100
* R efer to NFPA 220 for definition of non-combustible Type I and II building construction.
** FM Global Approval Guide. *** FM Global Property Loss Prevention Data Sheets 5-4 -- Transformers.

FM Approved Transformers include:  EATON Cooper Power Series ABB Siemens Eaton Cutler-Hammer GE Energy Square-D Prolec GE Int'l Wilson Transformer
 This list includes all the insulating liquid manufacturers listed by UL and FM Global as of the date of this publication. Refer to UL and FM Global for the latest lists.

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Appendix 5 - Outdoor installations per FM listing requirements
Less-Flammable Liquid-Insulated Transformers Compliance to NEC Section 450.23 per FM*** Listing Requirement Highlights

Reference Data TD900001EN
Effective January 2019

Non-Combustible Building

(Type I or Type II)* and

No

No Combustibles in the Area

Yes

FM Approved Less-Flammable Liquid**

No

Yes

Installation Incorporates FM LPD Sheet*** Requirements
Yes
Requirements per Liquid Listing
See Page 19 for FM Requirements Detail

No

NEC Code Requirements FM Listing Requirements

Requirements Per NEC 450.27

If installation presents fire hazard

Yes

COMPLIANCE WITH

one or more of the following

Yes

safeguards shall be applied: · Space Separation

NEC 450.23

· Fire Barriers

· Automatic Water Spray

· Enclosure

FM Approved Fluids include: ** Cargill Envirotemp FR3 Fluid (natural ester) M&I Materials MIDEL® 7131 (synthetic ester) Shell Diala® HFX (fire resistant hydrocarbon) Dow Chemical L-305, Y-7582 (silicone) DSI Alpha-1TM, Beta® (hydrocarbon) Dow Corning® 561 (silicone) Momentive Performance Mat SF97-50 Prolec GE Int'l VG-100

FM Approved Transformers include: ** EATON Cooper Power Series ABB Siemens Eaton Cutler-Hammer
* R efer to NFPA 220 for definition of non-combustible Type I and II building construction
** F M Global Approval Guide *** FM Global Property Loss Prevention Data Sheets 5-4 -- Transformers

NNote: NEC Section 110.3 (b) applies if the listing chosen for compliance specifically addresses outdoor application.

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Appendix 5 - Outdoor installations per FM listing requirements (continued)
Less-Flammable Liquid-Insulated Transformers Compliance to NEC Section 450.23 per FM Listing

FM Requirements Detail for outdoor installations

Yes

FM Approved Less-flammable liquid*

No

More than 500

No

gallons?

Spill exposure to building (ground

Yes

sloping toward building or level

Yes

No

US EPA Environmental Technology verification**
status for ready biodegradation

More than

Yes

500 gallons?

No

Containment per FM LPD***
Section 2.3.1.4
Yes

Yes

Containment per FM LPD*** Section 2.3.1.4

FM approved transformer* or
equivalent

Yes No

Yes
Minimum separation distance per FM LPD*** Section 2.3.1.1.1 Tables 5 & 6 · 3 feet horizontal · 25-50 feet vertical (depending on fluid volume)

Minimum separation distance per FM LPD*** Section 2.3.1.1.1, Tables 5 &
6 · 5-50 feet horizontal
(depending on fluid volume) · 25-100 feet vertical
(depending on fluid volume)

FM LPD*** Installation options for Mineral Oil or Non approved fluid · Minimum separation distance per Section
2.3.1.1.1 Tables 5 & 6 · 5-100 feet horizontal · 25-100 feet vertical OR · Fire barriers per Section 2.3.1.1.2 OR · Water Spray protection per Section
2.3.1.1.2
Yes

Yes

Yes

COMPLIANCE WITH NEC 450.23

* FM Global Approval Guide.
** E nvironmental Technology Verification Program, U.S. Environmental Protection Agency (Envirotemp FR3 fluid and BIOTEMP® fluid have ETV status for Ready Biodegradation).
*** FM Global Property Loss Prevention Data Sheets 5-4 -- Transformers.

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Notes

Reference Data TD900001EN
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Reference Data TD900001EN
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Eaton 1000 Eaton Boulevard Cleveland, OH 44122 United States Eaton.com
Eaton's Power Systems Division 2300 Badger Drive Waukesha, WI 53188 United States Eaton.com/cooperpowerseries
© 2019 Eaton All Rights Reserved Printed in USA Publication No. TD900001EN / CSSC-5936 January 2019

Eaton is a registered trademark.
All other trademarks are property of their respective owners.

For Eaton`s Cooper Power series product information call 1-877-277-4636 or visit: www.eaton.com/cooperpowerseries.


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