480V lighting versus 277V lighting
480V lighting versus 277V lighting
(OP)
what is the advantage of using 480v lighting versus 277v lighting? can i save any money on wiring?
klubie
klubie
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480V lighting versus 277V lighting
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RE: 480V lighting versus 277V lighting
RE: 480V lighting versus 277V lighting
RE: 480V lighting versus 277V lighting
I know that there are HID fixtures which can run off 480. As far saving money on copper wire...its probably going to be a wash. Although you do not have to run a neutral, you still have to run two current carrying conductors plus a ground wire (3 wires per fixture). I'm not sure about the harmonics...I'm assuming the fixtures are single phase, not 3 phase.
RE: 480V lighting versus 277V lighting
If you plan to power this lighting from a large 480V transformer, then the 277 V is a big pain in the neck. The use of 277V line-to-neutral loading requires that a neutral be provided in the incoming switchgear and that it be carried all the way down to the lighting panel. The neutral loads complicate the ground fault protection especially if you have a double-ended substation. You also run the risk of a ground fault in a lighting circuit taking down a large chunk of your 480V system.
Use of 480V fixtures will allow more fixtures per circuit and allow longer circuit runs.
If you want 277V just for lighting, a good solution is to provide a small 480 delta - 480/277V wye transformer.
Harmonics need to be considered, but I don't see that as a reason to not use 277V. There are other reasons why 277V is often a nuisance.
RE: 480V lighting versus 277V lighting
You can use single pole switches for 277, you need double pole switches for 480 volts.
Switches for 277 are readily available. 2 pole 480 volt switches are not as common and may be more expensive.
277 uses one breaker pole per circuit, 480 uses 2 breaker poles per circuit. For both 277 v and 480 V you can use equal 3 pole breakers if you don't want to control smaller circuits individually.
yours
RE: 480V lighting versus 277V lighting
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RE: 480V lighting versus 277V lighting
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