Photocells, please help...

Status
Not open for further replies.

lady sparks lover

Senior Member
I need a good manufacturer that makes photocells, and a wiring diagram.

I'm having the contractor install photocells mounted on the roof, but I need to help him/her how to wire it, and where to mount them. I know we are supposed to have them mounted facing north, but why?

Lady :)
 

charlie

Senior Member
Location
Indianapolis
Re: Photocells, please help...

Since we require photocells to be made to our specifications, I can't recommend a particular manufacturer. However, the reason for the photocell facing north is to have about the same amount of light in the area activate the light. If it faced east, the photocell would pick up the morning light earlier so it would turn off earlier. The same photocell would turn on earlier at night and waste energy.

The sun is low in the sky in the winter and would effect the photocell so north works the best and is the most consistent. :D
 

BruceH

Senior Member
Re: Photocells, please help...

I'm not trying to be funny here, but if you need to help your contractor wire a photo-cell, you need to find another contractor. Usually there are only three wires to worry about, line, load and neutral. Black is line, red is load and white is neutral. Tork makes a decent photo-cell, just remember to never try to connect a photo-cell energized because it will meet its demise prematurely. Also the manufacture's directions are usually included in the box the photo-cell comes in.
 

lady sparks lover

Senior Member
Re: Photocells, please help...

Originally posted by BruceH:
Also the manufacture's directions are usually included in the box the photo-cell comes in.
I need to spec a photocell on my drawings, and I'm not as familiar with photocell wiring, and mounting, so I thought I'd ask. :)

[ May 27, 2005, 11:51 AM: Message edited by: lady sparks lover ]
 

BruceH

Senior Member
Re: Photocells, please help...

Mounting is normally accomplished by inserting the stem of the photo-cell through a knock-out in a box and tightening lock-nut. Or just threading the stem into a threaded opening in a box or fixture. Head of photo-cell is normally adjustable.
 

charlie

Senior Member
Location
Indianapolis
Re: Photocells, please help...

Bruce, I am assuming that Lady is referring to a twist lock photocell and not the button type. The button type will not handle commercial applications with larger loads. :D
 

lady sparks lover

Senior Member
Re: Photocells, please help...

Originally posted by roger:
Patricia, go to these pages for some info.

http://www.tork.com/main40n.htm

http://www.intermatic.com/?action=cat&cid=52

Roger
Ok, now that helps!! Thanks Roger.

Yes, Charlie, I'm talking commercial.

It will be mounted on a school, which will have to be LEED certified. So we have to make sure the building lighting is energy efficient. We are using both outdoor and indoor photocells. The indoor will dim the light, when the daylighting level in the classroom is sufficient. I have the indoor one by Wattstopper, the the outdoor one kind of stumped me. Thanks all!! :)
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Re: Photocells, please help...

Another reason for having the cell face north is to prevent it from being damaged by direct sunlight. Many photo switches will become nonfunctional in a short time if they are installed so that the cell window receives direct sunlight. Having it face north solves that problem.

Don
 

hurk27

Senior Member
Re: Photocells, please help...

Patricia

A little note to be aware that there are different types of photocells the most common is the thermo type and then there's the relay type. In commercial, and industrial I try to always use the relay type as they offer more choices of wiring methods and also handle more load when it comes to HID type fixtures. The relay type also doesn't have the delay when turning on. But the cost of them is a little higher also. I think it is worth it. :D If you are going to feed contactors with them the relay type is the best choice.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Re: Photocells, please help...

Originally posted by hurk27:
By Don: Another reason for having the cell face north is to prevent it from being damaged by direct sunlight.
And since this is a international web site:
If you live south of the equator the direction would be south. :D
I thought I was going to be the first smartass to say that, so I'll have to one-up you another way:

Si tu vives a del sur del ecuador, tienes que poner el interuptor al sur. :D

(Since much of the southern hemisphere speaks spanish. Can't help those who speak portuguese or Swahili, but oh well. :D
 

hurk27

Senior Member
Re: Photocells, please help...

That's ok George I was going to mention about the damaging effect of the sun in my post, but I had a brain fart and when I click the post button I remembered it, but Don beat me to it. :D ;)
 
Status
Not open for further replies.
Top