Dick Strauss
01-28-2014, 1:42 PM
Has anyone had an issue with their VFD for their PM 3520 showing an Occ error?
A friend has a PM3520A (it is long out of warranty) that keeps tripping the internal breaker in the VFD and shows this error without any load on the motor (no belt=no spindle). The error is related to the output devices in the Delta brand VFD pushing too much current. I checked everything (main and remote switches, all wires, rheostat, braking resistor, motor resistance, etc) and everything checks out okay. The spindle turns normally with a very slight twist of the handwheel as usual. The motor is not shorted...I checked all pathways. I was able to unlock programming through 00-07 programming menu. I changed the ramp time to 10s and max frequency to 45Hz (I found that it triggered the code as the freq went above about 50Hz even with the long ramp time) I also made sure that no current boost was activated. It runs fine now without fault albeit slower than the oem setting of the max frequency of 130Hz. I don't want to tear into the VFD checking things as long as it still limps along.
PM wants $500 for a new Delta brand VFD that has to be programmed (I don't expect PM to cover it because of the age of the lathe). Does anyone repair these things for less than $500 that I've seen online?
Once it dies completely, I'd help him replace it. Has anyone here replaced it with a $160 2HP Teco FM50 VFD or similar and had excellent results (same smoothness and no extra noise)? I've used the 3HP Teco but don't know if they will produce the same smoothness in his lathe.
Be safe,
Dick
A friend has a PM3520A (it is long out of warranty) that keeps tripping the internal breaker in the VFD and shows this error without any load on the motor (no belt=no spindle). The error is related to the output devices in the Delta brand VFD pushing too much current. I checked everything (main and remote switches, all wires, rheostat, braking resistor, motor resistance, etc) and everything checks out okay. The spindle turns normally with a very slight twist of the handwheel as usual. The motor is not shorted...I checked all pathways. I was able to unlock programming through 00-07 programming menu. I changed the ramp time to 10s and max frequency to 45Hz (I found that it triggered the code as the freq went above about 50Hz even with the long ramp time) I also made sure that no current boost was activated. It runs fine now without fault albeit slower than the oem setting of the max frequency of 130Hz. I don't want to tear into the VFD checking things as long as it still limps along.
PM wants $500 for a new Delta brand VFD that has to be programmed (I don't expect PM to cover it because of the age of the lathe). Does anyone repair these things for less than $500 that I've seen online?
Once it dies completely, I'd help him replace it. Has anyone here replaced it with a $160 2HP Teco FM50 VFD or similar and had excellent results (same smoothness and no extra noise)? I've used the 3HP Teco but don't know if they will produce the same smoothness in his lathe.
Be safe,
Dick