480 volt lighting retrofits

[dwmacpherson]

I have (454) 480 volt 400 watt MH HID's I want to retro to T5HO's. My lighting guy is telling me I can save money by running them 277. My question to all out there... what does the code say about using a 2 pole breaker as a single pole. The savings would not be advantageous if I have to replace all of these expensive breakers. I do realize my load will change at the lower voltage, that will all be taken into consideration.

 

[StephenSDH]

I don't believe the code says anything against using two single phase loads from a of a 2 pole breaker. I know it is commonly done. Someone else can add more detail on this.

Why would it save you money? Are the ballast costs less? Sounds like the rewiring costs would undo any fixture savings.

 

[broadgage]

I cant see how any saving in running costs could result from useing 277 volts instead of 480.
Watts are watts, and the ballasts should be very slightly more efficient on 480 volt.
Assuming that the existing wires are to be re-used, then the loss in the wire will also be less at 480.

 

[dwmacpherson]

I cant see how any saving in running costs could result from useing 277 volts instead of 480.
Watts are watts, and the ballasts should be very slightly more efficient on 480 volt.
Assuming that the existing wires are to be re-used, then the loss in the wire will also be less at 480.

There is an additional cost to add a transformer to a fluorescent fixture to run it 480 volts.

 

[augie47]

not trying to second guess your wiring, but if you end up with MWBC you would need "simultaneous opening" on the breakers anyway

 

[broadgage]

There is an additional cost to add a transformer to a fluorescent fixture to run it 480 volts.

I presumed that 480 volt ballasts were available and were being considered.
If a transformer is to be used, then I would expect running costs to increase slightly on 480 volts due to the losses in the transformer.

 

[lefty]

power consumption (watts) is what your being billed for, remember watts in watts out. compare the wattage of the fixtures before you buy, these lighting retrofit fellas sometimes lead a person the wrong way, compare the wattage.

 

[lefty]

if the fixtures consume less wattage then i would use just one leg at 277 and cap the other off, look at your loads and try to keep your loads balanced as close as possible. this way you could leave your breakers in place.

 

[Cow]

if the fixtures consume less wattage then i would use just one leg at 277 and cap the other off, .

You figure he wants to pull a neutral to 454 fixtures just to tap them up 277v? I sure as hell wouldn't...

 

[frenchelectrican]

I don't know if I am little late or what .,,

But with high bay flourscent luminaire I do know they can get in 480 volts and the last time I did have to order in 480 volts it cost little more to buy it.
I will look at both angles to justify the cost and to the OP's numbers of luminaires I do not know if that have 20 amp circuits or what that is a open door question there.

But in France we have to have inline fusing for all ballast that is higher than 240 volts { remember we have 240 volt L - N system or 415 Volt L-L }

If that was for me I will try to stick with 480 volts the cost to reconferating the 480 volt receptale to 277 volts will outweight the benfit of using the exsting receptle etc.

Merci,Marc