600A Main Breaker

[Chris Stakem]

I need to fuse a 600A feeder down to 200A to serve a new ATS load. Does the disconnect need to be rated at 600A 0r 200A?

 

[jim dungar]

The disconnect needs to be rated no less than the size of the fuse you are installing in it.

 

[maghazadeh]

I need to fuse a 600A feeder down to 200A to serve a new ATS load. Does the disconnect need to be rated at 600A 0r 200A?

If the 600A feeder protected by a 600A fuse/breaker and that the feeder will be terminated in the disconnect, then, Yes disconnect must be 600A.
If you use the tap rule, that will be different story.

 

[iwire]

If the 600A feeder protected by a 600A fuse/breaker and that the feeder will be terminated in the disconnect, then, Yes disconnect must be 600A.

I disagree that the fused disconnect means must meet or exceed the rating of the circuit supplying it.

 

[maghazadeh]

I disagree that the fused disconnect means must meet or exceed the rating of the circuit supplying it.

So what you are saying is okey to install a 20A receptacle on a 60A branch circuit.
Or what is the different that OP terminate the 600A feeder in the 100 or 200A panel board instead of a 200A fused disconnect. My point being 600A feeder is protected by 600A fuse or bkr.

 

[iwire]

So what you are saying is okey to install a 20A receptacle on a 60A branch circuit.
Or what is the different that OP terminate the 600A feeder in the 100 or 200A panel board instead of a 200A fused disconnect. My point being 600A feeder is protected by 600A fuse or bkr.

Do you install 15 amp switches on 20 amp circuits?

The rules are different for switches, panelboards and receptacles.

 

[GearMan]

I need to fuse a 600A feeder down to 200A to serve a new ATS load. Does the disconnect need to be rated at 600A 0r 200A?

You mention a 600A main breaker in the header. Are you feeding from a panel or single enclosed breaker? Are you tapping off the 600A feeder? Not knowing quite what you have planned, I question the lug size on a 200A switch to accommodate a 600A feeder. Short circuit protection for the feeder is provided by the 600A breaker and overload protection for the 200A switch and the load are the fuses in the device.

 

[ronmath]

IMO I see no reason that you can't use a tap rule to make the connection. The tap length in this case would be zero as it is connecting directly to the lugs of the switch (assuming they will accomodate the wire size). Which rule of 240.21(B)(1) is being broken here?

 

[kwired]

Are you taping off of a 600 amp feeder with a 200 amp circuit, or are you supplying some existing 600 amp conductor that now only needs to be a 200 amp conductor?

 

[maghazadeh]

Do you install 15 amp switches on 20 amp circuits?

The rules are different for switches, panelboards and receptacles.

Question:
Can 14-2 wire be used for the switch leg of a light fixture where the branch circuit is protected by a 20-amp circuit breaker? If this is prohibited by the Code, why can 15-amp switches and receptacles be used on 20-ampere circuits?

 

[david luchini]

Question:
Can 14-2 wire be used for the switch leg of a light fixture where the branch circuit is protected by a 20-amp circuit breaker?

If it complies with the tap rules in 210.19(A)(4), then yes. If it doesn't, then no.

If this is prohibited by the Code, why can 15-amp switches and receptacles be used on 20-ampere circuits?

Because this is not prohibited by the Code.