[NJWVUGrad]

Any thoughts on what would govern the sizing of a cable pit formed into a pad below a piece of switchgear.

Basically the conduit would enter the pit from the side and terminate in a bushing (no 90) and then the cables would turn up to the lugs on the switchgear.

Since their are only conduits entering one side of the pit,I'm not quite sure what you would use to size the pit.

 

[macmikeman]

+ 5 times the size of diameter of the cable minimum bending radius. Physics probably dictates you should exceed that very liberally though.

 

[BBQ]

Unless they are truly cables the 5x does not apply

 

[BBQ]

For what it is worth everyone of these I have seen were sized to the same dimensions of the switchgear.

 

[ponyboy]

Be careful with vault installations. You must ensure you have a way to support the weight of the conductors if they're free airing up to say the high side of a ct cabinet. When you get into the several thousand amp range there is a massive amount of weight that you can't simply let the lugs support. Just saying, sometimes people don't realize this until they see the guts of the cabinet pulling down....

 

[Jlarson]

Be careful with vault installations. You must ensure you have a way to support the weight of the conductors if they're free airing up to say the high side of a ct cabinet. When you get into the several thousand amp range there is a massive amount of weight that you can't simply let the lugs support. Just saying, sometimes people don't realize this until they see the guts of the cabinet pulling down....

I've seen that more then once in treatment plants. Doesn't end well after a major fault either :laughing:

 

[ponyboy]

I've seen that more then once in treatment plants. Doesn't end well after a major fault either :laughing:

I hate vaults but the bosses insist on them for some reason. It's twice as much work for the same end result. Oh well

 

[Jlarson]

I hate vaults but the bosses insist on them for some reason. It's twice as much work for the same end result. Oh well

We do them when we have cable trenches.