# Supermarket Lighting Voltage



## LAElectrician (Dec 8, 2009)

I've done a lot of commercial electrical work, but never in a supermarket. Could someone tell me if the typical supermarket lighting voltage is 120V or 277V?

Thanks.


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## Going_Commando (Oct 1, 2011)

LAElectrician said:


> I've done a lot of commercial electrical work, but never in a supermarket. Could someone tell me if the typical supermarket lighting voltage is 120V or 277V?
> 
> Thanks.


I've seen both. Its like adult diapers. It Depends.


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## telsa (May 22, 2015)

It largely depends upon the age of the stores.

The Big Grocers work to two different designs in a new build.

Plan A -- this is their dream plan -- when they can get all the space they desire for parking and such.

Plan B -- this is their custom plan -- when they are stuck -- like building in San Francisco and other old neighborhoods.

Since they suck down so much juice, these outfits have the Poco plop a dedicated pad mounted transformer for all modern builds.

Half the time the grocer is stuck on 480Y277 -- both for lighting and for his monster 'freezer package' ( the condensers up on the roof ) -- and the other half he just stays at the old 208Y120.

I once built (retrofit and massive expansion) a Safeway that had 208Y120 existing -- and a second Service on the opposite side of the building was brought in at 480Y277. Yes, that's right, two services for one building, one owner, one retail space. A special cross-linking shunt trip circuit permitted the Firemen the ability to kill both sides from either side. He need not even touch the Main. (!)

[ The build was a total mess, BTW. ]

So, yes, it depends.


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## LAElectrician (Dec 8, 2009)

Thanks, telsa, great answer. BTW, combining more than one meter/power supply for any one building is strictly forbidden for any new building or power upgrade project in an existing building anywhere in Southern California.


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## Service Call (Jul 9, 2011)

I worked at a building here that had 120/208 at one end and 277/480 at the other. No notice at either place that there was a separate service. 


Sent from my iPhone using Tapatalk


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## five.five-six (Apr 9, 2013)

I did supermarkets for 2 years of my apprenticeship and they were all 277 lighting.... but those were just the ones I worked on. Given the choice, 277 makes way more sense.


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## telsa (May 22, 2015)

five.five-six said:


> I did supermarkets for 2 years of my apprenticeship and they were all 277 lighting.... but those were just the ones I worked on. Given the choice, 277 makes way more sense.


The issue that swings the decision is the monster compressor pack atop the store.

If the grocer gets a sweet bid for a 480 scheme, then that decides the whole issue.

Huffman's units are invariably 208Y120. ( the display cases ) These are always dripping condensate, and 120 L-N is about all that Huffman's attorneys care to deal with.

480VAC makes every kind of sense for the massive compressor rack that these stores have up top.

I have repeatedly run into lighting schemes that were 277VAC for all ordinaries -- but 120VAC for Emergency back-up circuits. Boy, are they fun to pipe. ( a typical stipulation in the contract )

The latest trend has been factory prepped distribution boards -- with integral dry-type step down transformers. These are directly purchased by the retailer, so the EC is left merely to anchor them down and tie them in.

The lighting package will also be directly purchased at a national chain level. 

ALL of the Big Boys run their builds to a variation of this game. Home Depot and Lowes take this to the limit. They even directly buy the conductors. (!)


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## frenchelectrican (Mar 15, 2007)

LAElectrician said:


> I've done a lot of commercial electrical work, but never in a supermarket. Could someone tell me if the typical supermarket lighting voltage is 120V or 277V?
> 
> Thanks.


120 or 277 is most common but all it depending on the exsting service supply voltage and some building as other poster in here mention multi service aka more than 2 service and it can have both 208Y120 or 120/240 SP or 240D120 and 480Y277 volts serivice.,,

But be aware some lumainiare some are still wired for 120 volts even thru they may upgraded to 480Y277 volts.

so try to get higher voltage if possible so you can have more lumaires per circuit. 

most larger one I know useally run on 277 volts.

but becarefull with emeregcy light circuits some are set up on 120 volts


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