Frequently asked questions
What is an SCF4 [IGBT short circuit] fault on an ATV61 or ATV71 drive?
28 September 2021Issue:
SCF4 fault on an ATV61 or ATV71.
ATV71 Altivar 71 ATV61 Altivar 61
IGBT short circuit fault. Will not clear with power cycle.
SCF4 or [IGBT short circuit] indicates that there may be a power component fault.
If the fault will reset after a power cycle, the recommendation is to perform a self test via menu [1.10 DIAGNOSTICS]. Select TEST PROCEDURES and then TRANSISTOR TEST. The Motor must be connected to perform this test. Note any results that are not OK.
IF Transistor Test results are all OK, or if the SCF4 fault will not clear after a power cycle, disconnect motor from the drive and test for proper operation without the motor. Note that Motor Control Type (menu 1.4) has to be V/F 2pts and Output Phase Loss has to be NO (menu 1.8) for this test. Attempt to run the drive at several different speeds, checking phase to phase voltage for balance at each speed.
This should only be performed by a qualified technician with appropriate PPE and test equipment. Consult product manuals for details.
If the drive still faults on SCF4 with the motor disconnected, motor control type at V/F 2pts and Output Phase Loss set to NO; contact the Drive Products Support Group at 888-778-2733, option 2 for Technical Support and then option 4 for AC drives and soft starts.