200 amp Main lug panel behind fused switch disconnect HELP!!!

[augie47]

Look at 408.36
1. A panel is required to be protected by and overcurrent device within the panel OR at any point on the supply side so the fusible sitch ahead of the panel meets that requirement.
BUT
the panel must be protected by an overcurent device having a rating not greater than the panelboard (buss) so the fuses in your switch can not be size greater than the rating of your panel buss,

 

[L4nd0n40]

Look at 408.36
1. A panel is required to be protected by and overcurrent device within the panel OR at any point on the supply side so the fusible sitch ahead of the panel meets that requirement.
BUT
the panel must be protected by an overcurent device having a rating not greater than the panelboard (buss) so the fuses in your switch can not be size greater than the rating of your panel buss,

Thank you Augie! Now my I ask the panel buss is rating is determined how? is it just rated for the amperage, of what the panel is ? so say if I buy a 200 amp 3 phase main lug panel the (buss) is rated for that so the fuses in the disconnect can be no greater than 200 amp fuses ???

 

[Little Bill]

The panel bus rating is determined by the mfg and will be listed on the panel spec sheet.
Yes, you can't feed a main lug panel with anything greater than the bus rating.
You have to look at the info, as some panels with different amperage main breakers can have a bus with a greater rating.
Example.......150A main breaker panel may have a 200A bus rating

 

[jap]

Please keep your Supervisor involved.

You had mentioned taking a Single Phase feed off of a 3 phase disconnect.

Are you familiar with a 240v 3 phase Delta service?

JAP>

 

[L4nd0n40]

Please keep your Supervisor involved.

You had mentioned taking a Single Phase feed off of a 3 phase disconnect.

Are you familiar with a 240v 3 phase Delta service?

JAP>

No jap I am not . This is a 120/208v 200 amp three phase service .

 

[jap]

No jap I am not . This is a 120/208v 200 amp three phase service .

That's a good thing.

Just wanted you to be aware to stay away from the high leg if taking a single phase feed off of a 120/240v 3ph service.

JAP>

 

[L4nd0n40]

Welcome to the forum.

If you mean feed the ML panel from the fuses, yes, as long as you're in the same structure.

Welcome to the forum.

If you mean feed the ML panel from the fuses, yes, as long as you're in the same structure.

When you say in the same structure do you mean the disconnect and the MDP have too be inside the structure I can’t feed (from the disconnect outside too the MDP inside) I would assume I can’t because I have too have some form of disconnect inside the building. Right ?

 

[LarryFine]

No. I'm not differentiating between indoors and outdoors. In or on the same structure is okay.

You can have the disconnect outdoors and a main-lug panel indoors in the same building.

If you were to run a feeder to another structure, a disconnect is needed on the second one.