Building Steel as ground

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curd

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Can anyone inform me as to what limitations the code places on using building steel columns as a grounding means? Is it safe to assume in an industrial environment where coulums sprout up in many places that a 480v branch circuit can come out of conduit to rails on a overhead crane without an EGC? And that because "all of this steel is up there" ,it will protect exposed wires in case of a ground fault? The circuit comes from a 60 disconnect fed off a busway feeder. Thanks in advance for your anticipated help>
 
Re: Building Steel as ground

Curt,
You are not permitted to use the building steel as an equipment grounding conductor. The only permitted equipment grounding conductors are listed in 250.118. Building steel does not appear in that list.
Don
 
Re: Building Steel as ground

Building steel can, and should, be a part of the Grounding Electrode System. But that is not what you seem to be asking about. I agree with Don. If you turn building steel into an EGC, you are going to ruin someone?s day. :eek:
 
Re: Building Steel as ground

Curt, building steel cannot be used as an EGC. It is used as an ground electrode, and should be used as such in high rise applications for SDS, but not EGC. Don a Charlie gave you good advice.
 
Re: Building Steel as ground

I think Curt is saying that he has seen a crane wired with 3 wires to the power rails and no EGC, this is acceptable, see 610.61
 
Re: Building Steel as ground

sjaniga,
In my opinion an EGC must be run with the circuit conductors and connected to the fixed structure of the crane. 610.61 permits the fixed and mobile parts of the crane to act as the EGC for the crane itself, but a path back to the power source is required.
Don
 
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