Hardware Ref, Installation, and Troubleshooting User guide

9Ć6
9.4 Checking Out the Power Modules with Input Power Off
Use the following procedure to check the drive's P ower Module circuitry with power off:
DANGER
DĆC BUS CAPACITORS RETAIN HAZARDOUS VOLTAGES AFTER INPUT POWER HAS BEEN
DISCONNECTED.
AF TER DISCONNECTING INPUT POWER , W AIT FIVE (5) MINUTES FOR THE D ĆC
BUS CAPACITORS TO DISCHARGE AND THEN CHECK THE VOLTAGE WITH A VOLTMETER TO
ENSURE THE DĆC BUS CAPACITORS ARE DISCHARGED BEFORE TOUCHING ANY INTERNAL
COMPONENTS. FAILURE TO OBSERVE THIS PRECAUTION COULD RESULT IN SEVERE BODILY
INJURY OR LOS
S OF LIFE .
Step 1. T
urn off and lock out input power. W ait five minutes.
Step 2. Remove the drive's cover .
Step 3. V
erify that there is no voltage at the drive's input power terminals.
Step 4. Check the D ĆC bus potential with a voltmeter as described in section 9.3 to ensure that the
D ĆC bus capacitors are discharged.
Step 5. Disconnect the motor from the drive.
Step 6. Check all AĆC line and D ĆC bus fuses.
Step 7. If a fuse is blown, use a multimeter to check the input diodes and output IGBT s. See table
9.1.
Note that 1Ć10HP drives do not have replaceable transistor modules: the entire drive must
be replaced if a transistor malfunctions. Intelligent P ower Modules (IPM) may be replaced if
they fail in a 60Ć150HP drive.
Step 8.
ReĆconnect the motor to the drive.
Step 9. ReĆattach the drive's cover .
Step 10. ReĆapply input power.
T
able 9.1 Ć Resistance Checks
1Ć60HP Drives
Input
Diode
No.
Meter
Connection
(+) (-)
Component is OK if
resistance (R) is:
Component is defective if:
1 ă* R/L1
50 < R < 10 Megohm Continuity (short circuit) or open when the meter is
connected with reversed polarity
2 ă* S/L2
connected with reversed polarity
3 ă* T/L3
4 R/L1 **
5 S/L2 **
6 T/L3 **
* (+) D ĆC Bus V olts power terminal
** (-) D ĆC Bus V olts power terminal