64
Checking Power Modules and Motor Input
with Input Power Off
Use the following procedure to check the drive’s power module 
circuitry with power off:
1. Turn off and lock out input power. Wait 5 minutes.
2. Verify there is no voltage at the drive’s input power terminals.
3. Using a voltmeter, check the DC bus potential as described in 
the section Verifying That DC Bus Capacitors Are Dis-
charged on page 21 to ensure the DC bus capacitors are 
discharged.
4. Check all AC line and DC bus fuses.
5. Use a multimeter to check the input diodes and output IGBTs 
if a fuse is open. See Table 8. Multimeter must have a func-
tion to select “Diode Test” mode. See Fig. 35 for Frame 7 
power module (19MV) and Fig. 36 for Frame 8-15 power 
modules (19XR).
6. Reapply input power. 
NOTE: Digital meters require a special diode check function because the current 
sourced by the meter during a normal resistance (Ohms) test is too low to accu-
rately test a diode. Make sure the meter is set to the diode test function. Voltage 
readings may not be exact as shown in above table, but look for consistency 
during each of the 4 tests. When performing a test that should return infinity (OL) 
as shown in above table, you may see a value slowly climbing toward infinity. This 
is a result of the meter charging a capacitor and is normal.
14
Resettable 
Fault
14136 Lineside IOC Flt
IOC Fault. Lineside hardware in the 
power module has detected an 
Instantaneous Over Current (IOC) event.
Replace the Ln power module. See the 
hardware service manual, publication 
750-TG100, for the replacement 
procedure.
Stop (Line Side Converter). 
Additional Fault Action. Fault opens 
main circuit breaker: No. Fault can 
automatically reset: Yes. Emergency 
override response: Cannot override 
this fault.
Table 7 — Fault Codes by Port (cont)
PORT
CONDITION
DISPLAY
TEXT
FAULT ACTION FAULT ACTION
TYPE CODE
WARNING
DC bus capacitors retain hazardous voltages after input power 
has been disconnected. After disconnecting input power, wait 
five (5) minutes for the DC bus capacitors to discharge and 
then check the voltage with a voltmeter to ensure the DC bus 
capacitors are discharged before touching any internal compo-
nents. Confirm that the DC bus has discharged before per-
forming diode checks. Failure to observe this precaution could 
result in severe bodily injury or loss of life. 
Table 8 — Diode Checks
METER LEAD
METER READING
(+) (-)
R
DC+ 0.20 to 0.75-v
DC- Infinite (OL)
S
DC+ 0.20 to 0.75-v
DC- Infinite (OL)
T
DC+ 0.20 to 0.75-v
DC- Infinite (OL)
U
DC+ 0.20 to 0.75-v
DC- infinite (OL)
V
DC+ 0.20 to 0.75-v
DC- Infinite (OL)
W
DC+ 0.20 to 0.75-v
DC- Infinite (OL)
DC+
R
Infinite (OL)
S
T
U
V
W
DC-
R
0.20 to 0.75-v
S
T
U
V
W