sIZING CIRCUIT BREAKER AND LIGHTING SWITCH

[huchin]

FOR A SINGLE PHASE LIGHTING CIRCUIT IS OK TO HAVE A 20A CB WITH A 15A SWITCH?
CANT FIND THE CODE TO RULE ON THIS .

 

[charlie b]

Re: sIZING CIRCUIT BREAKER AND LIGHTING SWITCH

I would say yes, because I can also find no explicit prohibition against it. The fact that you are talking about lighting makes this a continuous load. So you are limited to 80% of the 20 amp circuit rating, or 16 amps maximum. You must also ensure that the lighting loads do not exceed the 15 amp rating of the switch.

 

[bennie]

Re: sIZING CIRCUIT BREAKER AND LIGHTING SWITCH

huchin, your caps lock light is on

Charlie, is all lighting calculated at 125%?

 

[charlie b]

Re: sIZING CIRCUIT BREAKER AND LIGHTING SWITCH

There may be exceptions, but I don?t run into them often. Most of my company?s projects involve buildings. The spreadsheet that we use for panel schedules includes a 125% factor for loads associated with lighting circuits. It sounded to me that this was the same type of circuit that huchin was describing.

 

[websparky]

Re: sIZING CIRCUIT BREAKER AND LIGHTING SWITCH

2002 NEC 404.14 Rating and Use of Snap Switches.
Snap switches shall be used within their ratings and as indicated in 404.14(A) through (D).

It is acceptable to have a 15A switch controlling a lighting load that is supplied by a 20A OCD as long as the lighting load on that switch is 15A or less.

Has been this way for years!

 

[bennie]

Re: sIZING CIRCUIT BREAKER AND LIGHTING SWITCH

Derating for heat should limit the rating of the switch and circuit breaker to 80%, I would think.

15 amp switch= 12 amps load. Not worth installing a 15 amp on commercial wiring systems.