Fluke 902 Application Note


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Application Note
From the Fluke Digital Library @ www.fluke.com/library
Eric Sundby is a service
foreman, MacDonald-Miller Facility
Tools: Fluke 902 True-rms HVAC
Clamp Meter
Voltage and current tests,
phase imbalances in both voltage
and current, and surface temperature
Standardizing on clamp
meters for HVAC service
MacDonald-Miller Facility
Solutions is a leading construc-
tion, engineering, control sys-
tems and building services firm
headquartered in Seattle, WA.
The company’s Building Services
group is the largest commercial
HVAC service company in the
Northwest, with offices located
throughout Western Washington
and into Oregon. They provide
maintenance, repair, overhaul,
and installation of everything
from centrifugal and reciprocat-
ing refrigeration systems to elec-
tronic building control systems.
They also perform air balancing,
chemical treatment of water
systems, plumbing, and electri-
cal services and have extensive
experience with specialized
applications such as clean rooms,
computer rooms, research labs,
and medical and testing facilities.
Eric Sundby is a service fore-
man in the Everett, WA office;
he supervises ten field techni-
cians who work on all aspects
of HVAC, doing heating, cooling
and associated measurements,
electrical test on motors pumps,
compressors, electric boilers, fur-
naces and flame signals and the
list goes on.
The facilities cover “pretty
much everything commercial,”
says Sundby, from retail strip
malls to light commercial struc-
tures to high-rises to biotech
facilities, including hospitals,
medical facilities and clean
rooms used in research and
development. They also work
on cell sites, cell towers, switch
stations and telecommunication
MacDonald-Miller has stan-
dardized on the Fluke 902 Clamp
Meter for daily maintenance
work, using 80 of the instru-
ments for the day-in, day-out
voltage, current and temperature
readings. “For the day-to-day
stuff the Fluke 902 is pretty much
our workhorse,” says Sundby.
In addition to a 902, each
technician carries his or her
choice of personal instruments;
Sundby carries Fluke Model 77
and 23 Digital Multimeters, and a
52 temperature probe “for doing
other things, when I need to get
a little more technical.” Several
technicians also have calibra-
tors that make it possible to test
4 mA to 20 mA and low voltage
0 V to 10 V dc, 2 V dc to 10 V dc
signals. The company also has
some Fluke 789 meters in ser-
vice for control work and trouble
Checking temperature differences
across the exchanger, very verify
chiller barrel performance.
2 Fluke Corporation Standardizing on clamp meters for HVAC service
Picking a meter
MacDonald-Miller didn’t choose
the 902 on a whim. They did
their research, looking for a utili-
tarian meter that would make
the measurements needed, that
would be reliable (“these guys
trust the meters with their lives,”
says Sundby), that would handle
the day-to-day banging around
common to field maintenance,
and that would handle the envi-
ronment. While not the deciding
factor, cost was important as
well, considering the number of
meters involved.
All in a day’s work
While it would be difficult to
define a typical day for Sundby’s
crew—“Nothing is ever really
typical, because we’re so well
versed,” he explains—a typi-
cal job with rotating equipment
involves using the 902 to do
voltage and current tests, and
phase imbalances in both volt-
age and current. Measurements
on the rest of an HVAC system
include temperatures on pres-
sure, suction, discharge and
liquid refrigerant lines. “We do
delta Ts across the evaporator
coils and across the condenser
coils, and we check suction tem-
perature, discharge and liquid
temperatures,” Sundby explains.
“We use the 902 for that, too,
because it’s our all-in one; they
just switch a lead and they can
change to their temperature and
they got surface probes they use
and off they go.”
Knowledge is power
The regularity of maintenance
work is the source of much of
its effectiveness. As technicians
work on motors, says Sundby,
they make records of the reading
they take and enter them into a
database for predictive mainte-
nance purposes. “We try to trend
it, we try to keep a running log
on what equipment looks like,
and if we start seeing failures
we’re trying to predict failures,”
he explains.
They would like to implement
a full asset management system
that would collect equipment
history and also connect to the
accounting software and con-
struction departments, and have
been working at it for several
years. There’s still a ways to go
to gaining that edge, but predic-
tive maintenance goes on all the
same. “For the most part the guys
are consistent on their work-
load,” he explains. “They kind of
remember and they know what’s
been going on; they start watch-
ing for that trend of motors going
downhill and that type of thing.”
Good work takes training
Maintenance work on com-
mercial and industrial HVAC
equipment is not a trivial task,
and making sure the people
who do it are up to the task
involves more than just provid-
ing them with the proper test
instruments. Most newly-hired
technicians are graduates of
a two-year associate’s degree
program at a community college
or tech school, Sundby explains.
When they’re hired by Mac-
Donald-Miller or another union
contractor they enter a union
apprenticeship program that lasts
for four years—or five, for those
who don’t have that associate’s
degree. And even after six years
the training doesn’t stop. The
company maintains a large train-
ing facility in Seattle. “We put
on three-hour classes twice a
week.” says Sundby. “The guys
come in at night and get fed and
get to learn about new products
and testing and programming,
whatever it happens to be,” from
refrigeration to safety. In addi-
tion, suppliers conduct classes on
everything from meters to vari-
able frequency drives.
You’d think that union wages,
a solid company and a job that
can’t be outsourced overseas
would attract lots of applicants,
but Sundby reports that it’s get-
ting more and more difficult to
find qualified people. He’d like
to see more encouragement for
young people to consider alter-
natives to a four-year college
program. As he says, “not every-
body’s going to be happy with a
desk job.”
After all, Sundby says, part of
what’s made this country great
“is manpower, and labor, and
quality work.”
Liquid line temperature measurements for subcooling.
3 Fluke Corporation Standardizing on clamp meters for HVAC service
Growing green facilities
MacDonald-Miller has another, greener arm
of the business. Led by Perry England, the
sustainable, eco-friendly Building Performance
group helps customers plan, build, retrofit,
and maintain building environmental systems
for maximum efficiency and reliability.
Following LEED, Green Globes, Lean
Design, and other practices, the group has
built a uniquely integrated understanding of
green building automation technologies. Some
classic reliability practices transfer over, such
as preventive maintenance and equipment
modernization. What’s different is the layer of
documentation and highly networked tools for
data analysis and trending. England says the
change makes good business sense.
Customers are demanding green building
efficiency and changes in financial lending
models increasingly support it.
Safety first
Safety is an area of increasing
concern for everyone involved
in electrical work. Sundby cites
increasing emphasis on the
requirements of the NFPA 70E
Standard for Electrical Safety
in the Workplace. The standard
covers electrical safety require-
ments for employees involved
in the installation of electric
conductors, electric equipment,
signaling and communications
conductors and equipment, and
raceways. A big part of it is con-
cerned with protection against
Arc-Flash. While the standard
has been around since 1996,
Sundby says, it has moved to
the forefront, starting with a
change in clothing. Polyester is
out, and flame retardant cotton is
in, along with the proper gloves.
Lockout/Tagout is getting more
attention as well, but the work
that the MacDonald-Miller field
techs do involves live equipment:
“You can’t do too much testing on
equipment that’s sitting there,”
he says.
MacDonald-Miller’s servicing
operation must handle a wide
variety of tasks on different types
of equipment. By standardizing
on just a few Fluke instruments
and by providing its people
with strong training and support
the company has been able to
increase the effectiveness of its
operations and cut costs at the
same time. All in all, it’s a win-
win situation.
Taking current measurements at a 480 V chiller control, looking for
phase imbalances.
Fluke Corporation
PO Box 9090, Everett, WA 98206 U.S.A.
Fluke Europe B.V.
PO Box 1186, 5602 BD
Eindhoven, The Netherlands
For more information call:
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Web access: http://www.fluke.com
©2008 Fluke Corporation.
Specifications subject to change without notice.
Printed in U.S.A. 7/2008 3358336 AW-EN-N Rev A
Modification of this document is not permitted
without written permission from Fluke Corporation.
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