When things are tight,
reach for the Fluke T5
Application Note
No matter what the electrical
dilemma is, the solution always
depends on basic electrical principles: Ohm’s Law and V = IR,
where V is voltage, I is current,
and R is resistance. Enter the
Fluke T5-1
000.
Yes, the T5 is a general purpose volts-ohms-amps electrical
tester that measures ac and dc
voltage, and resistance values up
,000
to 1
stationary open jaws slide around
Ω. However: Onc
e its
a conductor, the T5 safely
measures ac current up to 100 A
without clamping the jaws shut
or breaking the circuit.
That “OpenJaw” technolog
allows the T5 to make highly
curate measurements in envi-
ac
ronments that would drive other
clampmeters into early retirement.
y
No extra hands needed
The T5 is one very compact little
meter. Easily cradled in one
hand, the T5 has a test lead slot
in its back, making the meter an
“extended handle” for the probe
and leaving the technician’s
other hand free to place the other
lead. It also features a large,
easy-to-read digital display and a
hold feature for checking the
value away from the “reading”
position. And like other Fluke
tools, the T5 automatically shuts
off after 45 minutes, prolonging
battery life, and is built to withstand falls. According to Duane
Smith, Senior Product Spec
at Fluke, “While we k
can handle falling off a ladder,
ive g
e is ver
ific Ltd
v
., a lumb
’t want to carry
emmer sa
’ve seen it sur
we
drops than that in the real
world.”
Convenienc
to Dale K
ber and head electrician at
Crow
in Mar
of in-plant troubleshooting. I own
several Fluke meters but there
one I carr
the time: the T5-1000. It’s an
awesome meter for a troubleshooter who doesn
a lot of tools around a large facility like our mill,” K
emmer, FlukePlus mem
ac
n P
ille, WA USA. “I do a lot
ysv
y in my hip pocket all
ialist
now the T5
reater
y important
er mill
’s
.
ys
-
Using the tester as an extended “handle” for either probe allows convenient two-hand operation.
From the Fluke Digital Library @ www.fluke.com/library
The “rocket,” as he calls his
T5, can be used almost everywhere in this facility, which has
a wide variety of electrical
devices from computers to large
horsepower motors. Most of the
machiner
planers, kilns, etc) is large.
Controls range from computers to
standard PLCs. “I end up using
the ‘rocket’ 90 % of the time,” he
adds. “I can operate it with one
hand and switch from volts to
amps to continuity with my
thumb. Being able to switch
measurements so easily speeds
up the troubleshooting proc
wrights at the Crown Pacific
fac
guys. I use the T5 in my training
to illustrate how to make basic
electrical measurements. It’s a
great teaching tool,” he says.
y (debarkers, saws,
ess.”
Mr. Kemmer also trains mill-
ility. “These are real hands-on
Fixed jaws go where
others can’t
The T5 can check current up
to 100 A without breaking the
circuit, simply by sliding its
fixed jaws around the connector.
It does this by measuring the flux
density around the conductor.
As Paul Knapp, electrical
foreman at Minneapolis-St. Paul
Airport (MSP), puts it, “All the
electrician needs to do is pull the
wire away from the wall far
enough to get it between the
jaws. Nothing needs to open or
close. The T5 works no matter
how much moisture, mud, dirt, or
ol from de-ic
glyc
encounters on the wires in the
airport’s lighting manholes or
taxi bases
proved troublesome when their
jaw ends corroded, often rendering them difficult to use or
entirely inoperative. This has
never been a problem with the
Fluke tool — it
ing operations it
. Moveable-jaw meters
’s impressive.”
Applications
The T5 does everything a standard clampmeter does, except measure dc current.
General applications
Check if a circuit is live before beginning work
•
Check individual voltages (either ac or dc)
•
Determine component resistances up to 1000 ohms.
•
Check circuit continuity
•
Residential applications
Measure loads on a branch circuit at a service panel
•
Measure the load side voltage of a circuit breaker or fuse
•
Map outlets to breakers
•
Industrial applications
Check circuit loading at panelboards (including feeder cables, branch circuits, and
•
neutrals) and the integ
Check for leakage currents in branch c
•
supply wire are placed in the T5’s jaws the reading should be zero. A reading other
than zero indicates that leakage current is returning on another path and, therefore, a
y load or poor insulation condition exists
leak
Motor measurements including loading value, current balance and for troubleshooting
•
control circuitry
The T5 is also handy when it comes to checking control functions during large
machinery installations. According to Kevin Gallimore, owner of Gallimore Services,
“When installing a machine and checking its sequencing, the small stationary jaws of
the T5 make it easy to check current flow and verify operation. Troubleshooting large
machines and distributed installation like HVAC systems can require two men on walkie
talkies, but with a T5, I can do much of it from the control panel.”
rity of a grounding circuit
ircuits. When both a neutral and corresponding
In order to make accurate current measurements using the T5, the
conductor should pass through the throat of jaws and parallel to its
axis as shown, in this example from the Minneapolis Airport. When
testing for the presenc
prior to b
the jaws is slightly less critical since no reading is expected for a
non-energized circuit.
2 Fluke Corporation When things are tight, reach for the Fluke T5
inning electrical repairs, plac
eg
e of power in a c
ircuit to verif
ement of the c
y that it is off
onductor in
Making electrical measurements with
the T5
oltage measurements
V
1. Turn the selector to the V. The meter automatically selects the correct internal circuitry
depending on the type of voltage being
measured. For volts dc and ac, the T5-600 is
rated for 600 V CAT III and the T5-1000 is rated
for 1,000 V CAT III or 600 V CAT IV.
2. Touch the probe tips to the circuit across the
load or power source in parallel to the circuit.
Either probe can be fitted into the back of the
meter for easy two-handed operation.
3. Record the reading, making note of the units of
measurement
.
4. If you can’t read the display, press the HOLD
button to freeze it, remove the meter from the
live circuit, and then check the value.
Resistance measurements
1. Turn off power in the circuit to be tested.
2. Turn the selector to
Ω.
3. Touch the probe tips across the designated
component or portion of the circuit.
4. Record the reading.
Continuity
Continuity is a quick go/no-go resistance test that
distinguishes between an open and closed circuit.
The T5 continuity tester beeps when it detects a
closed circuit (resistance less than 25 Ω) — no
reading is required — and when it encounters an
open circuit (resistance greater than 1000
Ω), “OL”
appears in the display.
Current measurements
1. Turn the selector to A.
e the jaw
Plac
2.
s of the meter around the c
tor. The conductor should be no larger than 0.5
in. diameter.
The conductor should pass through the sensor
3.
zone (noted by the circle at the base of the jaw
opening) and parallel to the axis of the slotted
opening. In a situation where checking for a
“hot” conductor is more important than the
absolute ampere reading, exact placement of the
jaws around the conductor is less important.
4. View the reading. Note that the HOLD function
can be used on all measurements as necessary.
3 Fluke Corporation When things are tight, reach for the Fluke T5
onduc-
Guidelines for working safely
High voltages and currents present in electrical power sys
tems can cause serious injury or death by electrocution or
burns. Only trained, experienced electrical or maintenance
technicians should test or modify electrical systems.
Never work alone.
•
Use caution when working above 30 Vac rms, 42 Vac
•
peak, or 60 V dc.
Do not use the tester around explosive gas, vapor, or
•
dust.
Do not use a tester if it is damaged or operating abnor-
•
mally. Before each use inspect the tester and tester
leads. Make sure the battery door is closed and latched.
Look for cracks, missing plastic, exposed metal, or damaged insulation. Replace damaged test leads before
using the tester. Verify its operation by measuring a
known voltage.
Replace batteries as soon as the low battery indicator in
•
the display appears.
Do not apply more than the rated voltage, as marked on
•
the tester, between terminals or between any terminal
and earth ground.
Use appropriate safety equipment such as safety glasses,
•
insulated gloves, mats, etc.
When using probes, keep finger behind the finger
•
guards.
Always connect the common lead before connecting the
•
live lead. Always disconnect the live lead first.
Make certain that all power has been turned off, locked,
•
and tagged out in any situation where direct contact
with circuit components is possible.
Do not use instruments on applications for which they
•
are not intended. Also be aware that if equipment is
used in a manner not specified by the manufacturer, the
protection provided by the equipment may be impaired.
Refer meter servicing to qualified personnel.
•
Clean the meter case with a damp cloth and detergent.
•
o not use abrasives or solvents
D
Fluke. Keeping your world
Fluke Corporation
PO Box 9090, Everett, WA USA 98206
Fluke Europe B.V.
O Box 1
P
Eindhoven, The Netherlands
For more information call:
In the U
Fax (425) 446-5116
In Europe/M-East/Africa (31 40) 2 675 200 or
ax (31 40) 2 675 222
F
In Canada (8
Fax (905) 890-6866
From other countries +1 (425) 446-5500 or
Fax +1 (425) 446-5116
eb ac
W
©2004 Fluke Corporation
Printed in U.S.A. 10/2004 2402573 A-US-N Rev A
.
up and running.
D
02 B
86, 56
1
00) 443-5853 or
. (8
.A
.S
KE or
LU
F
00) 36-
cess: http://www.fluke.com
. All rights reser
ved
.
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