Help with 277 V lights on 3 ph system

[jbgoosehunter]

Trying to run 2 277 Volt 1000 Watt HID Floods on one leg of a 3 ph 480 Volt 100 Amp fused disconnect which is running 2 30 Amp 3 ph AC units. When I tap into one leg of the power it zero's out my voltage on the leg im trying to use and raises the voltage on the other 2 legs. Wondering if it is just throwing it out of balance? What to do? Should I try and run the 2 fixtures from 2 different legs to help balance the load?

 

[chris kennedy]

Would this be an ungrounded delta? Where are you picking up the neutral for the 277? And why did you pick this source for your supply?

 

[jbgoosehunter]

Not sure if it is delta? The meter is located next to the disconnect it is an older system. There is a solid copper ground which I have hooked the neutral to coming off of the meter.

 

[stevebea]

Trying to run 2 277 Volt 1000 Watt HID Floods on one leg of a 3 ph 480 Volt 100 Amp fused disconnect which is running 2 30 Amp 3 ph AC units. When I tap into one leg of the power it zero's out my voltage on the leg im trying to use and raises the voltage on the other 2 legs. Wondering if it is just throwing it out of balance? What to do? Should I try and run the 2 fixtures from 2 different legs to help balance the load?

No..... if this is a disconnect for AC units its very doubtful you have a neutral. A 100A disconnect is not the place to look for a feed for 277V lighting.

 

[jumper]

Not sure if it is delta? The meter is located next to the disconnect it is an older system. There is a solid copper ground which I have hooked the neutral to coming off of the meter.

I am probably wrong, but why do I think you just connected 1P ungrounded/neurtral conductor to a GEC for an ungrounded 3P Delta supply.

What am I missing?

 

[stevebea]

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I am probably wrong, but why do I think you just connected 1P ungrounded/neurtral conductor to a GEC for an ungrounded 3P Delta supply.

What am I missing?

I'm thinking the same thing Jumper.

 

[Jnas480]

It does sound like you have open delta One of phase is grounded.

You are better off using a ballast kit for 480 volts. and this will solve your problem.

Good Luck

 

[LarryFine]

I agree: unbonded Delta (or even a Wye) and no neutral, only ground.

 

[LEO2854]

Trying to run 2 277 Volt 1000 Watt HID Floods on one leg of a 3 ph 480 Volt 100 Amp fused disconnect which is running 2 30 Amp 3 ph AC units. When I tap into one leg of the power it zero's out my voltage on the leg im trying to use and raises the voltage on the other 2 legs. Wondering if it is just throwing it out of balance? What to do? Should I try and run the 2 fixtures from 2 different legs to help balance the load?

Welcome to the forum
Should I try and run the 2 fixtures from 2 different legs to help balance the load?[/
Yes if you have two 1000 watt 277 volt HID Floods why not try to balance out the load.

 

[LEO2854]

Trying to run 2 277 Volt 1000 Watt HID Floods on one leg of a 3 ph 480 Volt 100 Amp fused disconnect which is running 2 30 Amp 3 ph AC units. When I tap into one leg of the power it zero's out my voltage on the leg im trying to use and raises the voltage on the other 2 legs. Wondering if it is just throwing it out of balance? What to do? Should I try and run the 2 fixtures from 2 different legs to help balance the load?

Welcome to the forum
Should I try and run the 2 fixtures from 2 different legs to help balance the load?[/
Yes if you have two 1000 watt 277 volt HID Floods why not try to balance out the load.Should I try and run the 2 fixtures from 2 different legs to help balance the load?[/

sorry for the double post my computer is having trouble

 

[don_resqcapt19]

Welcome to the forum
Should I try and run the 2 fixtures from 2 different legs to help balance the load?[/
Yes if you have two 1000 watt 277 volt HID Floods why not try to balance out the load.

If this is an ungrounded delta system, as it appears to be, you can't run 277 volt loads from it.

 

[LarryFine]

If it's 480v Delta, you can't suppy 277v loads from it anyway. You'd need to derive a neutral or use a transformer.