Feeding 277V lights off 480V circuit

[usmcgrover]

I'm working on a project to replace our 360W MH high bay fixtures with fluorescent fixtures. The 360W MH fixtures are currently fed with 480V 1 phase, no neutral. Our distribution system is 480 ungrounded delta, so there is no neutral available at the service, and there are no neutrals run to the lights.

I had a contractor in today to give a bid and offer suggestions, and one of the options he suggested was to install fixtures that have a small 480/277V transformer in them. The balllast would run off 277V from the small transformer.

Has anyone else seen this done? I like the idea of being able to use T8s instead of T5s, but I'm worried about potential problems with this setup.

 

[augie47]

curious.. were the lights in a building..seems a violation of 210.6.

If the circuitry will accept the 277 loads, I would think a simpler solution would be to add 480/480Y277 transformers at the source of the circuits..

 

[dbuckley]

Can you not get an electronic ballast that'll work at 480V?

Any transformer solution will consume electricity warming the transformers, and that might go against the intent of the retrofit.

 

[hillbilly1]

I know they make the T-5 fixtures with 480 volt ballast, the newer orange boxes use them.

 

[usmcgrover]

All of the above ideas are options we have on the table. I was just wondering if anyone had seen a retrofit done like this, as I have never heard of such a setup. Thanks for your input.

 

[winnie]

While we are putting options on the table that don't answer the original question You could use a grounding transformer to derive a neutral at the service, without needing a transformer with the full KVA rating of a 480: 480/277 transformer.

-Jon

 

[infinity]

If you're trying to use the existing wiring I don't see how adding a 480-480Y/277 transformer at the source will work.

 

[BullsnPyrs]

http://www.greenelectricalsupply.com/6-lamp-t8-480v-fluorescent-high-bay.aspx

6l t8 480v High Bay replacement. First listing on a BING search.

 

[CNC]

I've seen original installs with 277 to 120 step down transformers in individual fixtures. Im getting ready to retrofit fit them with a different fixture though. They are outdoor building bulkhead style fixtures, with 70w metal halide internals. They are getting a 277 volt 42w 4 pin 4100k retrofit, and ditching the MH stuff and step down transformer. I assume it was a design flaw, cause most of the property is 277

 

[Electric-Light]

Here's the thing...
http://www.gelighting.com/na/busine.../480VStep-DownTransformer_Sell_Sheet74903.pdf
GE has such transformers which specifically tells you not to use it in your application.

277v ballasts are designed to have nil voltage between case and white and not to exceed 277v between black and case.

Hook it up and fliip the switch and they'll light up, but you may run into excessive ballast failure rate.

I see both six lamp F54T5HO and six or eight lamp F32T8 with high ballast factor in gyms as one-for-one replacement for MH.

For standard F32T8, Advance or Howard doesn't make any.

Universal Lighting has exactly one product, B332IHRVHB-E designed specifically for high bay which can be used for two or three lamp, so you'll be using two of these for four or six lamp setup, or three for eight lamp. That one is designed to handle floating 347v above ground and its rated for use on phase to phase on 480Y/277v here, or phase-to-neutral on 600Y/347v in Canaduh.

You'll need to call Universal and ask about using it on ungrounded 480 delta.

http://www.unvlt.com/productLines/ap_sheets/ELFB/B332IHRVHB-E.pdf

I have no experience or field reports on that ballast so I can't really recommend or not recommend it. The efficiency should be better than using a transformer at fixture though. I believe the GE's 480->277v exists to fill the void in product line so its not completely dismissed from playing the game where the field is 480v.

 

[BullsnPyrs]

Just got a sales brochure from Phillips for this ballast ( JOP-2S84-G Ballast ) for use with the T8 VHO Extreme temperature lamp system. The savings isn't great, only 86 watts per fixture, but they are claiming 25,000 hours with a 12 hour average start.

 

[Electric-Light]

Just got a sales brochure from Phillips for this ballast ( JOP-2S84-G Ballast ) for use with the T8 VHO Extreme temperature lamp system. The savings isn't great, only 86 watts per fixture, but they are claiming 25,000 hours with a 12 hour average start.

Philips/Advance offers T5 VHO and T8 VHO system. The T8 VHO lamp, if I recall correctly has the same bi-pin socket as normal T8 lamps.

Nobody else offers T8 VHO. Philips lamp & Philips-Advance combo only as far as I know, excluding some cheap Chinese ones that may pop up.

if you install it and it doesn't catch on, parts become difficult to obtain and you maybe forced to change over.

 

[jmellc]

I've never worked with any 480 V lighting, though I've heard of it. I've installed Bollard post lights with multi tap from 120, 208, 240, 277, same thing with wall pack MH lights. Don't think any of them had a 480 option, though they may have.

 

[BullsnPyrs]

Philips/Advance offers T5 VHO and T8 VHO system. The T8 VHO lamp, if I recall correctly has the same bi-pin socket as normal T8 lamps.

Nobody else offers T8 VHO. Philips lamp & Philips-Advance combo only as far as I know, excluding some cheap Chinese ones that may pop up.

if you install it and it doesn't catch on, parts become difficult to obtain and you maybe forced to change over.

They do use the same bi-pin socket. With a relatively low eneregy savings per fixture the company I work for has decided to spec them for extreme temperature enviorements only.