Any suggestions with respect to locating a ground fault on a 240V delta where they do not want to turn off machines?
Old building complex, mix of wiring methods including knob and tube, buss duct, EMT, and rigid conduit. Cranky old CNC machines that do not like to be power cycled.
This 240V delta system supplies about 1/2 of the building load. Ground fault appeared sometime in the last 2 years. Was not present during last power quality audit. Building has a history of ground faults according to the current electrician.
With all of the metal piping, was not sure if a thumper signal injector would work. Utility feed is 480V 1500 KVA. 240V is created by 1000 KVA transformer.
