Carrier 19XRV specifications Diode Checks, Meter Lead Meter Reading

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 five minutes.

2.Verify there is no voltage at the drive’s input power termi- nals.

3.Using a voltmeter, check the DC bus potential as de- scribed above to ensure the DC bus capacitors are dis- charged.

4.Disconnect the motor from the drive.

5.Check all AC line and DC bus fuses.

6.Use a multimeter to check the input diodes and output IGBTs if a fuse is open.

7.Check motor impedance.

8.Reconnect the motor to the drive.

9.Reapply input power. See Tables 7 and 8.

WARNING

Confirm that the DC bus has discharged before performing diode checks.

Table 7 — Diode Checks

NOTE: Digital meters require a special diode check function because the current sourced by the meter during a normal resis- tance (Ohms) test is too low to accurately test a diode. Make sure the meter is set to the diode test function. Voltage readings may not be exact as shown in above tables, but look for consistency during each of the 4 tests. When performing a test that should return infinity (OL) as shown in above tables, you may see a value slowly climbing toward infinity. This is a result of the meter charging a capacitor and is normal.