We have two 600 kw Detroit generators with asco t switches.During our monthly load test on occasion the 800 amp main breaker will trip.This only happens on the transfer back to standard power.It's a known fact that the asco's switch too fast resulting in a short.The generators can be anywhere from 0 to 180 degrees out of phase with the utility.The building motors basically dynamically break and feed back into the busses as they spin down.Other strange things have started to happen as well.For instance in one area of the building up to 50% of the electronic ballasts in the fluorescent lights will fail and have to be replaced.I would think that this is due to either the basic input rating or the K rating the xformer that services that particular area.Has anyone seen this before?It's a new system and the electrical engineers have been out twice in the last year to monitor and solve the problem to no avail.Why not install an in phase monitor to delay the transfer?That breakers going to fail sooner or later at this rate.
