BB0141NE
ZP-BB04E
MOM200A/600A
15
5 APPLICATION ExAMPLES
Measuring resistance at
bus-bar joints
Important
Read the manual and comply with the
Safety instructions before using the micro-
ohmmeter.
Always comply with local safety regula-
tions.
Fig. 3
1]
Make certain the mains are de-energized and
the test object is grounded.
2]
Keep the micro-ohmmeter disconnected from
the mains while making connections.
3]
Ground the micro-ohmmeter.
4]
Connect the micro-ohmmeter’s current cables
to the test object, see fig. 3. Do not connect
the sensing cables. Measurement will be
done manually using an external portable
voltmeter.
5]
Connect the micro-ohmmeter to the mains.
6]
Turn on the ON/OFF switch.
7]
MOM200A
: Select the desired current (100 A
for example) using the "Test current switch".
MOM600A
: Select the desired current (100 A
for example) using the proper "Test current
push button".
8]
Clear, 0-set, the instrument by turning the
knob (16) on the variable transformer down
to "0", whereupon it will enter the current-
generation mode and LED (12) will light up.
9]
Increase the current as close as possible
(±1 A) to the desired value (100 A in this case,
which was the current you just selected). Set
the current accurately using the digital meas-
uring instrument.
10]
Using an external voltmeter, measure the
voltage drop (voltage) across each contact
element within every section of the bus-bar
being tested. The multimeter must be set to
DC and to measure voltage. You must calcu-
late the actual resistance yourself.
Example
: If the voltage drop is 0.0067 V at
a current of 100 A, the resistance will be
0.0067/100 ohms, i.e. 67 microohms.
11]
Turn off and disconnect the micro-ohmmeter
from the mains before doing any disconnec-
tion work or moving any cables or wiring.
