# photocell and lighting contactor.



## HARRY304E (Sep 15, 2010)

nkalghatgi said:


> I have a 480/277 V panelboard. This panelboard feeds 277 single phase lighting circuits. It also feed a 277:120/240V transformer. This transformer feeds a 120/240V 12 circuit panelboard.
> 
> I have a roadway lighting contactor which I show connected after the 480/277V breakers.
> From 120/240V panelboard, I have a 120V feed to a 3 way switch (auto, ON and OFF) which controls the photocell and timeclock (both are connected in parallel) which then control the contactor.
> ...


Yes, the load side of the photo cell can feed the coils in all three contactors.


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## wildleg (Apr 12, 2009)

(2011) 410.130 D -> 410.141 read 410.141, because I believe you have to comply with that


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## LGLS (Nov 10, 2007)

Most photocells are rated at 1800w tungsten.


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## OaklandElec (Jan 4, 2011)

Call an electrician?


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## LGLS (Nov 10, 2007)

nkalghatgi said:


> I dont want to feed the switch from 120/240V panelboard. Can I feed it directly from the transformer?


 You cannot feed the control circuit from the transformer. You must have overcurrent protection from the panelboard.


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## Southeast Power (Jan 18, 2009)

Can you explain to us how you intend to use power from the transformer?


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## Spunk#7 (Nov 30, 2012)

Duck Soup! Next?


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## Chrisibew440 (Sep 13, 2013)

In auto you will feed your photocell so when dusk hits the photocell closes energizing your coils on all your contactors. The on position will be your override for testing the lights during the day. When turned to on or "hand" you will energize your coils on all your contactors bypassing the photocell. This will re- energize the switch leg from your photocell but that's ok. And off is off. Excuse me, I missed the time clock. So it will be in auto you energize your photocell then at dusk that will energize your time clock. Easy money. Then your time clock will be set for certain times which will control your contactors.


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## LGLS (Nov 10, 2007)

I'm not getting the reason for a photocell AND a time clock. If the time clock is to shut down the lights at a predetermined time, then the control wiring is different than if the time clock is to act as a redundant backup in case of photocell failure.


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## Southeast Power (Jan 18, 2009)

IslandGuy said:


> I'm not getting the reason for a photocell AND a time clock. If the time clock is to shut down the lights at a predetermined time, then the control wiring is different than if the time clock is to act as a redundant backup in case of photocell failure.


Some places like to turn on signs and stuff like that from dusk until closing time. A time clock will always have to be adjusted to come on, a photo control eliminates that problem and turns the load on or off at a specific time each night.


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## Chrisibew440 (Sep 13, 2013)

Chrisibew440 said:


> In auto you will feed your photocell so when dusk hits the photocell closes energizing your coils on all your contactors. The on position will be your override for testing the lights during the day. When turned to on or "hand" you will energize your coils on all your contactors bypassing the photocell. This will re- energize the switch leg from your photocell but that's ok. And off is off. Excuse me, I missed the time clock. So it will be in auto you energize your photocell then at dusk that will energize your time clocks normally open set or sets of contacts. Easy money. Then your time clock will be set for certain times which will control your contactors.


Correction:
The photocell will feed your normally open contacts on your timeclock.


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## LGLS (Nov 10, 2007)

jrannis said:


> Some places like to turn on signs and stuff like that from dusk until closing time. A time clock will always have to be adjusted to come on, a photo control eliminates that problem and turns the load on or off at a specific time each night.


True. But he said this is for a roadway lighting contactor. Around these parts, if roadway lighting is employed it's on dusk to dawn, controlled by either photocell or an astronomical time clock, but never both.


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## Shockdoc (Mar 4, 2010)

If you're government is willing to cover my relocation expenses, I will glady relocate and design and wire all of your countries street lighting and municipal electrical needs.


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## MaxH (Mar 12, 2014)

The load of the cell will feed the contactors..


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