PowerTec Regenerative Brushless DC Motor Control 1000AR - Manual (Page 51)

Page
50
Model 1000AR Installation and Operation Manual
6/4/2001 © copyright 1997 by Powertec
I O C TESTS:
An Instantaneous Over Current (IOC) fault is a serious matter. An IOC fault is indicated when the drive has
detected a potentially damaging amount of current going into the output transistor stage. Whenever possible, avoid
trying to restart the drive after an IOC fault until the following tests have been performed:
1. Turn off power and wait for the main power capacitors to discharge.
2. Turn the ILIMIT potentiometer fully Counter-ClockWise (CCW).
3. Disconnect the motor power leads and check the motor for grounds.
4. With power still off, perform the Transistor Module Static Test (page 32).
5. Re-apply power and perform the Transistor Leakage Test (page 34).
6. If any of the Driver board LED’s are on now, change the driver board.
7. Press the START button and rotate the motor slowly by hand. Watch the driver board LED’s to see
which ones are turning on and off. If the IOC LED comes on at some point in the rotation, change the
transistor block connected to that driver.
8. Turn off the power and, after the main capacitors have discharged, re-connect the motor and test the
entire motor power circuit for grounds again.
9. Turn power on and begin the start-up procedure again, turning up the ILIMIT potentiometer slowly to
catch a possible overcurrent event.
O V/ UV TESTS:
An OverVoltage/UnderVoltage (OV/UV) indication may come on for many reasons. The important point to
remember is that the OV/UV indicator applies to the BUS voltage.
Make sure there are no common buss connections or bus loaders causing problems with the proper charging
and maintenance of the bus voltage.
1.
Before turning off the main power, measure the AC line voltage at the input to the drive. It should be
the nameplate voltage +/- 10%. If it is not, correct it.
2.
Assess when the OV/UV indication occurred. The OV/UV trip occurs:
• If the BUS voltage exceeds 121% of nominal bus (see troubleshooting chart, page 35 for
voltages) for any period of time. This may occur if the line voltage exceeds 121% of nominal,
or
• If the BUS voltage drops to less than 85% of nominal bus voltage for a period of time
exceeding 80 milliseconds (0.08 seconds), or
• If the BUS voltage drops below 75% of nominal bus voltage for any length of time, or
• If the charging contactor drops out.
3.
In the case of 380VAC and 460VAC drives, check the balance of the voltage across the capacitor bank
halves. (Measure across R1 and R2). The voltages should not differ by more than 10%. If the voltages
are unbalanced, change the Capacitor board.
4.
Do not assume that the AC line voltage which is measured while the drive is off will be the same while
the drive is running the motor under load. Measure the AC line voltage under both circumstances.