wirenut1980
Senior Member
- Location
- Plainfield, IN
I have a customer with a laser cutting machine from Germany, who after a momentary outage on the 69 kV transmission system claimed they had a 24 volt circuit board damaged. The customer is fed off a 12.47 kV distribution circuit fed by the transmission system, their service is 480 V ungrounded delta. The machine in question is fed from a 480 V delta to 480Y/277 V transformer. Grounding appears to be correct based on visual inspection only. The machine has several transformers within it to feed PLC's, relays, and circuit boards. No other boards in the same machine were damaged, no boards in other machines in the shop were damaged. This board's power supply is connected to the 480 V bus (480 V input, 24 V output). I thought I had read somewhere that power supplies fed from 480 V were more susceptible to damage than if they were fed from 120 V source. Any reliable information to back that up out there? Otherwise, I cannot come up with a good explanation as to why the board failed. Maybe a bad component that failed due to the stress of the quick off-on?
Thanks for any insight!
Thanks for any insight!