Ups Gec

[arnettda]

Hi. I am having an issue with a ups systems grounging electrode conductor. It is a 20kv system with a maintenace bypass cabinet. The by pass cabinet needs a GEC. I believe I need a GEC for the UPS since it is a seperetly derived system. Do I need two seperate GEC that go back to the main service. I have one for the Bypass cabinet that the mfg required to be the same size as the ungrounded conductors. Can I tap off from one to the other with an apprved method?
Thanks Dave

 

[brian john]

Does the UPS have a 3 wire input and a 4-wire output and the bypass is a 4-wire or 3-wire?

 

[arnettda]

ups

ups

My fed going into bypass is three wires. There is three wires going out to the ups and 4 wires coming out of the ups. The output of the bypass to my load is 4wires plus a ground.

 

[ron]

When the UPS is in bypass, where does it gets its source neutral? Does the bypass have a transformer, so then it derives its neutral on the bypass output?
Often, if there is nothing in the bypass path to derive a neutral, 4 wires are brought into the bypass, and its that bypass neutral that gets solidly connected to the UPS output neutral, and the GEC and the N-G bond is one in the same with the upstream feeder/service connections.