Maytag MFR Series Service Manual page 158

5. Remove the cover of the inverter to gain
access to the motor connections on the
right side and the input power connections
on the left side.
E500 series inverter (See page 4-36)
D700 series inverter (See page 4-38).
6. Measure voltage from Positive (+) to
Negative (-) terminals of the inverter.
nOTe: This voltage measurement must be
below 24VDC before attempting to remove
the inverter drive or contactor from the
washer. If voltage is not below 24VDC, wait
another 10 minutes and repeat step 6.
E500 Inverter
Negative (-)
Input Power
D700 Inverter
Negative (-) Positive (+)
Input
Power
CHeCk DC BuSS vOlTaGe
1. Check DC Buss voltage between Positive
(+) and Negative (-) terminals.
2. Unplug washer or disconnect power.
3. Connect voltage measurement equipment.
nOTe: Make sure voltmeter is set to DC
voltage of a setting higher than the expected
reading. Black and Red leads of the meter
need to be polarity sensitive. Make sure
black lead is in Negative port of meter and it
is touching Negative (-) contact on inverter.
Positive (+)
4. Plug in washer or reconnect power and
measure voltage.
5. Formula to determine DC Buss voltage
between Positive and Negative terminals
on the inverter is 1.4 x input voltage (for
example; 1.4 x 240 VAC = 336VDC Buss
voltage).
6. Unplug washer or disconnect power.
7. If DC Buss voltage is 10% or more higher or
lower than expected, replace inverter.
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