Customer tap box connected to secondary spot network

[living2learn]

I am helping a facility out and noticed that they had a secondary spot network with the fault contribution around 75,000A symm. They have a homemade tap box (no ul listing, field fabricated with bus bars with very small standoffs). Does this box need a ul listing and be properly braced for the fault current it could recieve?

 

[dpc]

Which side of the meter is it on? It only needs a UL listing if someone makes one with a UL listing. When you start poking around in low voltage network vaults, you'll find lots of scary things.

 

[living2learn]

It is the customers tap box located in their main electric room. It is where the utiltiy and customer meet. I stay very far away from utility vaults!

 

[dpc]

If the inspector didn't object, I would say it apparently did not require a UL label at the time it was installed. Is this 208 V? The fault current drops drastically as the distance from the transformer increases. I guess I wouldn't make an issue of it unless this is something you will be modifying. If this was an underrated circuit breaker, I'd approach it differently, but this may not even be a problem.

 

[living2learn]

It is 480V and I am doing a building evaluation and thought this was worth mentioning. My logic for this critical site is if there is a large fault the tap box may explode.