Fluke 43B
Applications Manual
40
Checking Current and Current Imbalance
After checking voltage imbalance, check for current and current imbalance.
Unbalanced currents cause overheating and reduce motor life. Also single
phasing (complete loss of power on one of the phases feeding the motor) may
cause overheating in the two other phase windings.
1
Open the main menu.
2
3
Make connections as shown below. Run the motor at full load.
If no current is present, you may assume an open fuse or winding.
Write down the current reading (A
1
).
4
Repeat this measurement for phase 2 and phase 3. Write down the
values for A
2
and A
3
.
VOLTS
/
AMPS
/
HERTZ
Summary of Contents for 43B
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