USMC1302
Senior Member
- Location
- NW Indiana
Was at a neighboring school system the other day when they recieved a call that power was out at a large middle school, and the lights were "surging". Rode along and found their stand-by generator running, and upon entering the electrical room, noted the main was open with indicator of a Ground Fault. Every so often(didn't think to time it), the building's lights(supposedly not EM) would come back on for several seconds and then go out, as if the utility power were trying to re-energize. I checked, and the visual indicator on the main was open. I recommended we shut down everything, including the generator, which we did. I suspected the chiller might be the culprit, so we opened the feeds tothe generator in the electrical room and also the local disconnects at the chiller. There was a small kVar unit that appeared to be connected on the load side of the chiller disconnect.
The chiller was later confirmed to have a grounded compressor by a service tech. Keeping the chiller locked-out, the Xfer switch was manually place back to utility, and the main closed. Everything appeared ok. What was the cause of the lighting "surges"?
The chiller was later confirmed to have a grounded compressor by a service tech. Keeping the chiller locked-out, the Xfer switch was manually place back to utility, and the main closed. Everything appeared ok. What was the cause of the lighting "surges"?
