Main lug panel

[ceb58]

Help settle a disagreement. The scenario. A 100 main lug panel. Guy at work swears that you can install a larger size breaker,say a 150amp, and use it as a main. I say no because of the 100amp rating. He says you can because it is the lugs that are rated for 100amp not the buss. Code reference ether way

 

[Pierre C Belarge]

The circuit breaker protects the bus, if the bus is rated at a lower ampacity than the circuit breaker, the circuit breaker is no longer protecting the bus.
The bus can be rated higher, not the circuit breaker.

 

[Buck Parrish]

I don't have a code reference.
It is the UL Listing on the side of the panel that you go by. If it says the panel is rated for 100 amps. Then it will require a 100 amp main maximum.

 

[Pierre C Belarge]

If your friend is looking for the code reference, tell him it is.......

Section 101 - Introductory to Common Sense of the NEC & Electrical Industry

Written by Experience and Time
Published by I Told You So
139th Edition

 

[480sparky]

If your friend is looking for the code reference, tell him it is.......

Section 101 - Introductory to Common Sense of the NEC & Electrical Industry

Written by Experience and Time
Published by I Told You So
139th Edition

Maybe 90.1(C) as well? :grin:

 

[Twoskinsoneman]

408.36 Overcurrent Protection. In addition to the requirement
of 408.30, a panelboard shall be protected by an
overcurrent protective device having a rating not greater
than that of the panelboard. This overcurrent protective device
shall be located within or at any point on the supply
side of the panelboard

 

[Pierre C Belarge]

408.36 Overcurrent Protection. In addition to the requirement
of 408.30, a panelboard shall be protected by an
overcurrent protective device having a rating not greater
than that of the panelboard. This overcurrent protective device
shall be located within or at any point on the supply
side of the panelboard

That is the secondary requirement, one needs to use my section as the primary requirement. :grin:

 

[infinity]

If the feeder to the panel is protected by a 100 amp OCPD does it really matter if the CB in the panel is 150 amps and used a disconnect?

 

[M. D.]

If this is a sub panel being fed from a properly sized opd then a 200 amp breaker could be used,.. as it is simply a disconnect... I'm thinking this might be what the guy at work had in mind???

 

[Dennis Alwon]

I agree that it would still have the protection but I don't believe the panel would accept the 150 amp breaker. The panel would not be listed for that use.

 

[ceb58]

If this is a sub panel being fed from a properly sized opd then a 200 amp breaker could be used,.. as it is simply a disconnect... I'm thinking this might be what the guy at work had in mind???

I agree with that but this idiot is trying to say you can up the rating of the panel by bypassing the lugs.

 

[Rockyd]

I'm going to go with 110.3(B). Bet your idiotic friend can't get any manufacturer to go along with his hair-brained thought patten !