Carrier D2-3466-2 - Manual (Page 22)

6-4 Carrier VFD Quick Reference
6.3 Checking the Power Modules and Motor with Input
Power Off
Use the following procedure to check the drive’s Power Module circuitry with power off:
Step 1. Turn off and lock out input power. Wait five minutes.
Step 2. Verify that there is no voltage at the drive’s input power terminals.
Step 3. Check the DC bus potential with a voltmeter as described in section 6.2 to
ensure that the DC bus capacitors are discharged.
Step 4. Disconnect the motor from the drive.
Step 5. Check all AC line and DC bus fuses.
Step 6. If a fuse is open, use a multimeter to check the input diodes and output
IGBTs. See table 6.1.
Step 7. Check motor impedance.
Step 8. Reconnect the motor to the drive.
Step 9. Reapply input power.
!
ATTENTION: 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 components. Failure to observe this
precaution could result in severe bodily injury or loss of life.