FA242938
28 September 2021
Issue:SCF4 fault on ATV12 drives
Product Line:Altivar ATV12
Environment:All
Cause:ATV12 drive is powering up with an SCF4 fault.
Resolution:SCF4 means IGBT short circuit fault.
Possible issues: Internal power component short circuit detected at power on. The drive may need to be replaced if the fault is coming up on power up. Check for any exploded/burnt electrical components on the drive. Also try running the drive without the motor leads connected and see if the fault persists.
A static check can be performed on the drive:
Checking The Input and Output Diode Bridges
This test is done using a digital multi-meter in diode test mode to check that the transistors and diodes are not short-circuited.
ALL TESTS ARE TO BE PERFORMED WITH ALL SOURCES OF POWER REMOVED FROM THE DRIVE
For Altivar Drive up to 25hp
- Instrument
- Use Digit-Meter with a diode scale
- Measurement
- Locate PA+ and PC- input on drive power terminals (should be close to your power connection terminals)
- Set meter to diode scale
- To measure Input diodes
- Place black on positive bus (PA+) and red on L1
- Get readings and then move to L2 and then L3
- When done swap red and black probes and measure again between (PA+) to L1...L3
- Readings should be OL in one direction and a low voltage reading the other way (Example 0.3v)
- To measure Output diodes
- Place black on positive bus (PA+) and red on T1
- Get readings and then move to T2 and then T3
- When done swap red and black probes and measure again between (PA+) to T1...T3
- Readings should be OL in one direction and a low voltage reading the other way (Example 0.3v)
For Altivar Drive over 25hp
- Drive uses SCRs on the positive input bridge and diodes on the negative. For the Output Bridge its all diodes.
- Instrument
- Use Digit-Meter with an ohm and a diode scale
- Measurement
- Locate PA+ and PC- input on drive power terminals (should be close to your power connection terminals)
- To measure Input SCRs and diodes.
- Set meter to ohm scale
- Place black on positive bus (PA+) and red on L1
- Get readings and then move to L2 and then L3
- When done swap red and black probes and measure again between (PA+) to L1...L3
- Readings should be at least 50kohms.
- Set meter to diode scale
- Place black on positive bus (PC-) and red on L1
- Get readings and then move to L2 and then L3
- When done swap red and black probes and measure again between (PC-) to L1...L3
- Readings should be OL in one direction and a low voltage reading the other way (Example 0.3v)
- To measure Output diodes
- Place black on positive bus (PA+) and red on T1
- Get readings and then move to T2 and then T3
- When done swap red and black probes and measure again between (PA+) to T1...T3
- Readings should be OL in one direction and a low voltage reading the other way (Example 0.3v)