Equipment Ground currents

[HYDL]

Is there a standard that dictates how much equipment ground current is too much? Certainly, the ideal is zero, but what would be considered an acceptable level?

 

[davidbeach]

Probably less than an amount that would prompt the question. Depends on where you are, what codes govern, etc.

 

[waross]

Another related issue is if the ground currents are increasing, what about touch voltages now and in the future when the equipment fails completely.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[HYDL]

This is a 1200 amp emergency feeder at a Hospital. EGC has 1.9 to 4.8 amps and max of 12 amps of leakage current.

 

[alehman]

1.9 to 4.8 doesn't seem too bad to me. Can you identify any particular source?

 

[waross]

What is the EGC? Is there a neutral ground at the generator that is allowing some of the neutral current to pass on the ground conductor?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[davidbeach]

Based on past experience, I'd say that less than 10A is probably not worth chasing down unless it is causing some specific problem. One source can be dual source lighting (normal and emergency into the same luminaire) with the two neutrals tied together.

I'd just continue to monitor the current and watch for sudden increases and try to figure out what causes them; otherwise leave it for those times that you don't have anything else to do.