# Panel info

#### horsegoer

##### Senior Member
Have a 277v panel with 1P lighting loads that total 15,000W.Panel info is not fully designed.

1. What size panel/main breaker would be in the lighting panel.
2. What size breaker would you have feed the lighting panel.

Thanks.

#### Dennis Alwon

##### Moderator
Staff member
Can you balance the load at 5000 watts per phase or is it 15,000 watts / phase?

total 15000W

#### infinity

##### Moderator
Staff member
Are you asking for the absolute minimum size panel and feeder that you can install? Although you could I wouldn't go below 60 amps.

#### horsegoer

##### Senior Member
Are you asking for the absolute minimum size panel and feeder that you can install? Although you could I wouldn't go below 60 amps.
Ok, 60A but how would you the panel breaker from the watts?

#### electrofelon

##### Senior Member
Ok, 60A but how would you the panel breaker from the watts?
Is this a 480/277 three phase panel? I will assume it is since anything else would be an oddball:
15,000/(480x1.732)=18 amps.

Does the 15k include the 125% continuous factor?

#### Russs57

##### Senior Member
I'm not even an electrician and I wish guys could say thinks like; I have a 4 wire, 3phase, 480/277 Wye panel. Stating only the loads leads to lots of unnecessary guessing. I mean I suppose I "could" have a single phase 120 X 277 VAC transformer at my house for exterior lighting.

#### horsegoer

##### Senior Member
Is this a 480/277 three phase panel? I will assume it is since anything else would be an oddball:
15,000/(480x1.732)=18 amps.

Does the 15k include the 125% continuous factor?
Thanks. I'm not sure.

#### horsegoer

##### Senior Member
ok so I'd assume in the calculation steps for the breaker feeding the panel, the panel size and the feeder for the panel one sizes the panel first, the breaker that feeds that panel then the feeder to the panel? thanks

#### infinity

##### Moderator
Staff member
The load calculation will tell you the minimum panel size from there you can size the feeder. You can size everything to the minimum or you can go over the minimum size to allow for future expansion.

#### horsegoer

##### Senior Member
The load calculation will tell you the minimum panel size from there you can size the feeder. You can size everything to the minimum or you can go over the minimum size to allow for future expansion.
Then the breaker feeding the panel is sized to the feeder size?

#### infinity

##### Moderator
Staff member
Yes, the breaker is protecting the feeder conductors and the panel if has no main.