Fender washers on ground lug

[JJWalecka]

Looking for reference materials regarding the proper installation of ground lugs. Where does it specify only a certain grade bolt can be Used? Where does it say fender washers can only be used in this application?

Thanks

 

[kwired]

110.3(A) which leaves evaluation of whether something is suitable wide open to opinion of the person doing the evaluation.

or

110.3(B) in which listing or labeling instructions for a specific item will give you any specifics that apply.

I don't think you will find anything in NEC that is specific on this topic.

 

[iwire]

110.3(A) which leaves evaluation of whether something is suitable wide open to opinion of the person doing the evaluation.

or

110.3(B) in which listing or labeling instructions for a specific item will give you any specifics that apply.

I don't think you will find anything in NEC that is specific on this topic.

I agree with all of the above.

My own rule for lugs is pick hardware that fits the factory sized hole and leave the fender washers out of it.

Often, but not always, I will order grade 3 bolts for transformer lugs. The only reason for this is that they are a graded bolt unlike the cheap hardware we typically use.

 

[Ponchik]

As mentioned earlier, I don't think you will find any section in NEC specific to the washer. The only thing close to that is in 250.8 that talks about threaded screws. 250.12 talks about removing paint.