Site Lighting MOCP

[Npstewart]

Good evening,

Im working on a project where the site lighting went from standard 25' poles which I was feeding with multiple 20A/2P circuit breakers through a contactor. The lighting has been revised to groups of 400W metal halide fixtures which resembles a stadium light. I forget where but I remember reading that I can feed these lights with a breaker rated up to 50A so I was thinking of changing to 50A/2P breakers, does anyone know if this is permitted. I recall reading something about requiring HID circuit breakers however im not sure if this will fit into a standard square d panel.

Thanks!

 

[Smart $]

Only thing I recall is that any circuit 30A and greater requires heavy-duty lampholders... 210.23.

 

[iwire]

Good evening,

Im working on a project where the site lighting went from standard 25' poles which I was feeding with multiple 20A/2P circuit breakers through a contactor. The lighting has been revised to groups of 400W metal halide fixtures which resembles a stadium light. I forget where but I remember reading that I can feed these lights with a breaker rated up to 50A so I was thinking of changing to 50A/2P breakers, does anyone know if this is permitted. I recall reading something about requiring HID circuit breakers however im not sure if this will fit into a standard square d panel.

Thanks!

Yes I believe you can but the issue of voltage drop and wire size comes up right away.

 

[Npstewart]

OK great, I already figured out my voltage drop and it was in excess of 13%, after I increased one wire size it went down to around 3.1%. I decided to use a 30/2 with a #8 wire.

Much appreciated!

 

[augie47]

Did you verify the rating of your contactor contacts ?

 

[Npstewart]

I will be sure to call out for a contactor capable of carrying the current. Im still in the design phase. We typically dont call out for a model of contactor, just the rating and number of poles.

 

[steve66]

OK great, I already figured out my voltage drop and it was in excess of 13%, after I increased one wire size it went down to around 3.1%. I decided to use a 30/2 with a #8 wire.

Much appreciated!

You might want to double check that. I find it hard to believe a single size increase in wire made a 10% difference in voltage drop.

 

[SceneryDriver]

Did you verify the rating of your contactor contacts ?

Not sure if there is a specific rating for contacts for HID lamps. I know there's a "tungsten" rating for switch and contactor contacts to account for the high inrush of a cold incandescent filament. It might be worth looking into though, to ensure long contactor life.


SceneryDriver