# Will 208-277 photocells work on 240 V?



## kbatku (Oct 18, 2011)

I'm trying to find a 240 volt analog photocell to run four 400 watt HPS lights. I don't want to run an electronic photocell because they hunt too much (switch on and off rapidly at dusk and dawn) and this isn't good for the bulbs. All I can find listed are 208-277 eyes which I don't know if they will work. 208 and 277 are distinct voltages from 240 and while 240 may technically land between 208 and 277 I'm puzzled if they would be OK to use. Any experience or thoughts on this?


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## wcord (Jan 23, 2011)

That is the voltage range the photocells will work with.
Therefore no problem on 240


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## Wardenclyffe (Jan 11, 2019)

*Photocontrol: 120/208 to 277V AC, 1,800 Max. Watt, 8.3 A Max. Incandescent Amps, 1.5, 2.25*


https://www.grainger.com/product/615T90?gucid=N:N:PS:Paid:GGL:CSM-2295:4P7A1P:20501231&gclid=Cj0KCQjwhsmaBhCvARIsAIbEbH5_BKEbbs5ni2PzNNWMsbmIVeDWDN8_koTviyMEpgv2mGhcpspHecAaAh6aEALw_wcB&gclsrc=aw.ds



Might not hold up to 4 HPS without using a contactor,


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## wiz1997 (Mar 30, 2021)

A photocell, a contactor, a time clock and a switch to over ride the photocell.

You're probably not going to find a photocell that can handle the amperage


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## MikeFL (Apr 16, 2016)

Generally speaking when you see a hyphen, it means "from this to that"
And if you see a slash it means "this or that".

120-277 includes 208 and 240
115/230 means 115 or 230.


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## Almost Retired (Sep 14, 2021)

wiz1997 said:


> A photocell, a contactor, a time clock and a switch to over ride the photocell.
> 
> You're probably not going to find a photocell that can handle the amperage


why the clock ?


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## Veteran Sparky (Apr 21, 2021)

kbatku said:


> I'm trying to find a 240 volt analog photocell to run four 400 watt HPS lights. I don't want to run an electronic photocell because they hunt too much (switch on and off rapidly at dusk and dawn) and this isn't good for the bulbs. All I can find listed are 208-277 eyes which I don't know if they will work. 208 and 277 are distinct voltages from 240 and while 240 may technically land between 208 and 277 I'm puzzled if they would be OK to use. Any experience or thoughts on this?


240 will work because Cell is 208-277. Need a contactor however, because photo cell as switch for a run of lights is no good because it does not disconnect both hots when off.


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## dspiffy (Nov 25, 2013)

Almost Retired said:


> why the clock ?


Same question!

I've seen this done and never understood it.


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## MikeFL (Apr 16, 2016)

Clock in parallel with photocell assures lights will not go out at night even if the photocell is subjected to very bright light.
Also allows lights to come on during a storm mid-day.
Bypass switch lets you periodically inspect your lights during daytime hours when they otherwise would be off.

I concur on the 2 pole contactor suggestion.


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## wiz1997 (Mar 30, 2021)

Almost Retired said:


> why the clock ?


MikeFL pretty much nailed it.

Redundancy for one, either the time clock turns the lights on, or the photocell does.

This setup was favorable to businesses that operate 24/7.

The 7 day clock can also be programmed to keep the lights off on weekends or to turn half the lights off during non business hours.

It's also a safety factor.

I too, have seen lightning flashes that would make the photocell trigger off.

Parking lots could be dark for 15 minutes or more waiting for things to cool down.

Female employees complain a bunch when they have to go to their car in the dark.


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## micromind (Aug 11, 2007)

I've found that photocells don't last very long with more than a couple of amps of load on them. When they drive a relay though, they last a very long time.


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## Wardenclyffe (Jan 11, 2019)

Are you an Electrician??

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## kbatku (Oct 18, 2011)

I am an electrician thanks


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