# Lighting Contacors



## MDShunk (Jan 7, 2007)

If you screwed up the switch wiring, there is a way you can use timers to use a mechanically held lighting contactor. Want a diagram?


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## Selectric (Aug 18, 2009)

SPDT ice cube relays work well to link a SP switch or PC to a mechanically held contactor.


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## oldtimer (Jun 10, 2010)

MDShunk said:


> If you screwed up the switch wiring, there is a way you can use timers to use a mechanically held lighting contactor. Want a diagram?


 I would like to see a wiring diagram! I like to keep a file of different wiring diagrams.

Some times they come in very handy.


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## MDShunk (Jan 7, 2007)

I can type it faster than I can draw it. 

You have a wall switch sending 120V up to the contactor when you want lights on, and no voltage when you want lights off.

Great. Have that light switch control the coil of an ice cube relay only. That's the only thing that light switch will control.

Power the C terminal of that ice cube relay all the time w/120 volts. The NC contact of that relay will go to one interval timer set for 2 seconds. The NO contact of that relay will go to a second interval timer set for 2 seconds. 

The interval timer coming off the NC terminal of that relay will control the "off" function of the mechanically held lighting contactor.

The second interval timer coming off the NO terminal of that relay will control the "on" function of the mechanically held contactor.

Description of operation:

Wall switch is turned on
Power is passed to coil of ice cube relay, energizing the NO terminal.
Interval timer is energized from relay NO terminal, and energizes the lighting contactor 'on' coil for 2 seconds.
Timer times out, power is no longer passed to lighting contactor, but lighting contactor remains latched in.

Wall switch is turned off.
Power is no longer passed to coil of ice cube relay, relay contacts change state, and relay energized NC terminal
Second interval timer is energized from NC relay terminal, and energizes the contactor 'off' coil for 2 seconds.
Timer times out, power is no longer passed to lighting contactor, lighting contactor stays off.


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## 10492 (Jan 4, 2010)

How does using timers quiet the chatter from the LC?

Isn't that the OP's problem?

Never mind, I missed Marc is using a mechanically held, and the OP is using electricaly held.


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## MDShunk (Jan 7, 2007)

Dnkldorf said:


> How does using timers quiet the chatter from the LC?
> 
> Isn't that the OP's problem?


He's got the coils energized all the time. I suspect that's where all his noise is coming from. He has no choice, since he's electrically holding them with a wall switch. Mechanically held contactors just slap in once, and then they're silent.


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## 10492 (Jan 4, 2010)

MDShunk said:


> He's got the coils energized all the time. I suspect that's where all his noise is coming from. He has no choice, since he's electrically holding them with a wall switch. Mechanically held contactors just slap in once, and then they're silent.


I know that. If he has an electrically held, I fail to see how timers will quiet it.

He might have a voltage problem feeding the contactor if it's a long run.

Seen that before.


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## MDShunk (Jan 7, 2007)

Dnkldorf said:


> I know that. If he has an electrically held, I fail to see how timers will quiet it.
> 
> He might have a voltage problem feeding the contactor if it's a long run.
> 
> Seen that before.


Because he only has to energize the coil for a second, and not 24/7. The noise is coming from the coil. That's why people buy mechanically held contactors. To get rid of the noise.


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## 10492 (Jan 4, 2010)

Marc, I understand mechanically held contactors. I hate when the release coils burns out, when then aux contact on the side of the coil sticks. 

I put in many electrically held, and haven't had any problems with them.

I have came across MH that failed, and just by-passed the mechanical part, because low and behold, the main coil was continous duty rated.

If you add ice cubes, where the heck do you mount them? A seperate enclosure? If his electrically is chattering due to installation screws or voltage, then I agree, just go buy a mechanical and swap the whole thing out.

He isn't telling us whether his contactor is for a lighting panel with the contactor in the bottom of the panel, or a seperate enclosure with branch circuits feeding it.

Still confused at to what his problem is.


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## 10492 (Jan 4, 2010)

Wireless, whose brand and model number contactor are you using?

Is it a SQ D?


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## guest (Feb 21, 2009)

Bolds added by me:



Dnkldorf said:


> How does using timers quiet the *chatter* from the LC?
> 
> Isn't that the OP's problem?
> 
> Never mind, I missed Marc is using a mechanically held, and the OP is using electricaly held.





Dnkldorf said:


> Marc, I understand mechanically held contactors. I hate when the release coils burns out, when then aux contact on the side of the coil sticks.
> 
> I put in many electrically held, and haven't had any problems with them.
> 
> ...


Nowhere did the OP say or imply that the contactors are _*chattering*_, which is a whole different ballgame. I am 99.9999999% positive he's referring to the loud buzzing most AC contactors make. 




Dnkldorf said:


> Still confused at to what his problem is.


I think because you are fixated on the chattering idea. :laughing:

So here it is as I see it:

Problem: AC electrically held contactors are buzzing when energized. Noise is loud enough to be objectionable. 

Solution: See MDshunk's EXCELLENT post describing the use of the ice cube relay, interval timers and mechanically held contactors. It would take very little time and effort to wire up and will solve the problem.


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## Wireless (Jan 22, 2007)

Dnkldorf said:


> Wireless, whose brand and model number contactor are you using?
> 
> Is it a SQ D?


The contactors are cheap off brand variety, it was the only one I could I find that is officially rated for lighting. 
After reading Marc's post I realized I can use mechanically held with no problem. I originally thought I couldn't if I wanted the wall switches to ba able to controll the contactors, right now they are only controlled by a timer.


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## 10492 (Jan 4, 2010)

mx, Marc.

He doesn't have a constant hot anywhere to swap the EH with the MH?

That's your fix using the ice cubes and timers.

Never seen it done. I would of ran a constant hot to the MH.


And yes, I think my brain stuck on the chattering, which still could be mounting screws or a cheap contactor. I don't come across obnoxiuos chattering with new installs.

Neat idea.:thumbsup:


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## 10492 (Jan 4, 2010)

Wireless said:


> The contactors are cheap off brand variety,


Tah-dah

Had to be.

So in a nut shell, you're into changing the contactor out anyway?


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## Wireless (Jan 22, 2007)

Dnkldorf said:


> Tah-dah
> 
> Had to be.


Which is why I am looking for others!


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## 10492 (Jan 4, 2010)

SQ D is all I would install.

You need a model number?

How many pole, how many amp, coil voltage?


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## Wireless (Jan 22, 2007)

Dnkldorf said:


> SQ D is all I would install.
> 
> You need a model number?
> 
> How many pole, how many amp, coil voltage?


20a 120v 8,6, &4


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## guest (Feb 21, 2009)

Dnkldorf said:


> mx, Marc.
> 
> He doesn't have a constant hot anywhere to swap the EH with the MH?
> 
> ...


You don't need a separate CH per se. For the output (contact) side of the Ice cube relay, (the side firing the interval timers and MH contactor coils) you can use the hot from one of the lighting circuits. I have seen such setups in some larger cinemas for work lighting. 



Wireless said:


> The contactors are cheap off brand variety, it was the only one I could I find that is officially rated for lighting.
> After reading Marc's post I realized I can use mechanically held with no problem. I originally thought I couldn't if I wanted the wall switches to ba able to controll the contactors, right now they are only controlled by a timer.


Ah, ha. As Dnkldorf pointed out, there's your problem. I find it very hard to believe that SqD doesn't have ANY contactors "officially" rated for lighting. Virtually every contactor I have ever run across has "Tungsten", "Ballast" or "Inductive" ratings for the contacts. 

Your choices to solve this are:

1: Mechanically held with the ice cube and interval relays;
2: Replace the cheap contactors with better ones;
3: Try installing thin rubber pads under each contactor to try to kill the noise;
4: Another thought I had, which is install a DC power supply (24 or 48v), have the switch control that, and replace the contactors with DC coil units.


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## 10492 (Jan 4, 2010)

Wireless said:


> 20a 120v 8,6, &4


If I'm reading this PDF right, 8 pole LXG80V02.

MH in a Type 1 enclosure.

Eyes are bugging me.

http://ecatalog.squared.com/pubs/Motor Control/Lighting Contactors/8903CT9701.pdf


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## 10492 (Jan 4, 2010)

mxslick said:


> You don't need a separate CH per se.


For Marc's fix, no. 

Wiegh the cost of the timers, relays and labor vs tapping the CH off the timer back to a MH realy.

Plus you have more pieces to fail.

He does come up with some thinkers. Where he comes up with this stuff is beyond me.


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## frenchelectrican (Mar 15, 2007)

There are few electrically held lighting contractors some of them I do add a recfier to convert to DC and use the DC coil that useally kill the clatter coil on the contractor { get a full bridge recefier that work the best }

Otherwise get mech held contractor with relay cube with time cut out like what MD did describe which I have done few time.

Merci.
Marc


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## 10492 (Jan 4, 2010)

Boy, did I have a brain fart last night.

Totally outthought this.

I would be ashamed to show you the paper towel diagrams I drew out.

WTF was I thinking?

A clear mind does wonders.


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## hardworkingstiff (Jan 22, 2007)

I've always liked the KISS principle.

















Keep It Simple Stupid


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## 10492 (Jan 4, 2010)

hardworkingstiff said:


> I've always liked the KISS principle.
> 
> 
> 
> ...


I took something simple and complicated the heck out of it, without knowing I was doing it, at the time.

It happens..........


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## mdfriday (May 14, 2007)

I have put rubber behind the contactors when mounting them in a cabinet. This helps with the vibration, and the initial kick. 

The relay idea is cooler though.


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## Mike_586 (Mar 24, 2009)

Dnkldorf said:


> I took something simple and complicated the heck out of it, without knowing I was doing it, at the time.
> 
> It happens..........


LOL yeah it happens. 

Sometimes when you're in the thick of things, you just can't see the forest from the trees and do some strange things. Things you look back on and just wonder WTF you were thinking, or if you even were thinking :laughing:

Me and my colleague were agonizing how run a series of exposed EMT in an ugly spot with what little material we had available and there had to be pull points in that section of the run. One of the apprentices showed up looking for more orders overheard part of the conversation, looked at it and in about 5 seconds said "Can you do _____?". We just looked at each other and burst out laughing. The kid saw the solution instantly while we must have spent 10 minutes trying to come up with an elegant solution.

That was just a few weeks ago.


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## hardworkingstiff (Jan 22, 2007)

Mike_586 said:


> Me and my colleague were agonizing how run a series of exposed EMT in an ugly spot with what little material we had available and there had to be pull points in that section of the run. One of the apprentices showed up looking for more orders overheard part of the conversation, looked at it and in about 5 seconds said "Can you do _____?". We just looked at each other and burst out laughing. The kid saw the solution instantly while we must have spent 10 minutes trying to come up with an elegant solution.


Reminds me of an old story from the 60's.

A tractor trailer drove under a bridge and got stuck. Couldn't pull forward or backward. Engineers and supervisors were out there thinking of how to deal with the situation. Suggestions were, unbolt the structure (overpass) and lift it with a crane to get it out, another was cut the truck and trailer up in pieces. A kid walking by asked..... Why don't you just let the air out of the tires and drive it out?

I think not over-thinking something is the hardest thing some people have to overcome when it comes to troubleshooting.


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## Wireless (Jan 22, 2007)

mxslick said:


> You don't need a separate CH per se. For the output (contact) side of the Ice cube relay, (the side firing the interval timers and MH contactor coils) you can use the hot from one of the lighting circuits. I have seen such setups in some larger cinemas for work lighting.
> 
> 
> 
> ...


 
I didn't say Square D doesn't make it, none of my local supply houses have it in stock. My original question was, what is a good contacator to replace these with?


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## JRaef (Mar 23, 2009)

I helped on a project in Las Vegas on one of the big new hotels. The initial designer put electrically held lighting contactors in a wall box of every room along with an occupancy sensor, so when you left the room, all the lights went out. Good idea, bad implementation because even with decent contactors (Sq. D by the way), people could hear them humming at night when they were trying to sleep and everything else was silent. We ended up using a little 20A contactor from Siemens that is specially designed as a low noise contactor, totally solved the problem. Not many people stock them unfortunately, but Siemens Industrial Distributors can order them for you. They only come in 4 pole but they are tiny, so 2 of them is still smaller than the average 8P lighting contactor. Cheap too, I think we paid $19.00 each, although that was 2 years ago.

Link


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## Frank Mc (Nov 7, 2010)

JRaef said:


> I helped on a project in Las Vegas on one of the big new hotels. The initial designer put electrically held lighting contactors in a wall box of every room along with an occupancy sensor, so when you left the room, all the lights went out. Good idea, bad implementation because even with decent contactors (Sq. D by the way), people could hear them humming at night when they were trying to sleep and everything else was silent. We ended up using a little 20A contactor from Siemens that is specially designed as a low noise contactor, totally solved the problem. Not many people stock them unfortunately, but Siemens Industrial Distributors can order them for you. They only come in 4 pole but they are tiny, so 2 of them is still smaller than the average 8P lighting contactor. Cheap too, I think we paid $19.00 each, although that was 2 years ago.
> 
> Link


Wow that sure looks small.....wish we could pay $19 dollars for Siemens contactors..
Frank


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## Wireless (Jan 22, 2007)

Well I switched them out to Square-D definitave load contactor (which happened to have a label on the side with their ratings for lighting) 2 out of three are fine, but one is just as bad as the cheap bunch! 

It is interesting though, I mentioned to the counter guy that the ones I have are noisy. His response was i am doing something wrong, I brought one of them in that had not been installed yet to try and magically it worked fine. They didn't have enough of the Square-D ones so I used that "good" one and boy what a racket! 

Maybe I am doing something wrong........


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## cdnelectrician (Mar 14, 2008)

Wireless said:


> Well I switched them out to Square-D definitave load contactor (which happened to have a label on the side with their ratings for lighting) 2 out of three are fine, but one is just as bad as the cheap bunch!
> 
> It is interesting though, I mentioned to the counter guy that the ones I have are noisy. His response was i am doing something wrong, I brought one of them in that had not been installed yet to try and magically it worked fine. They didn't have enough of the Square-D ones so I used that "good" one and boy what a racket!
> 
> Maybe I am doing something wrong........



There are a few different types of "contactors". There are definite purpose, Lighting and motor control contactors (IEC and NEMA) which most supply houses will have in stock and which some electricians will just blindly ask at the counter "I need a contactor, whatever is cheap" and they get a definite purpose usually open type contactor...which is generally made for intermittent duty....and cheap. Other guys use what they have sitting around in the shop...sure this klockner moeller IEC contactor will work for these MH lights! And it even has a 4th contact! Wonderful! 

If you have wired a lighting contactor to be energized continuously order an actual Lighting contactor, the contact pads are heavy duty and generally replaceable in the field and the coil is rated for continuous duty and will not chatter unless you have an under voltage issue. It is common practice to use a continuously energized lighting contactor to control lighting, shouldn't be a problem:thumbup:


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## cdnelectrician (Mar 14, 2008)

Wireless said:


> Well I switched them out to Square-D definitave load contactor (which happened to have a label on the side with their ratings for lighting) 2 out of three are fine, but one is just as bad as the cheap bunch!
> 
> It is interesting though, I mentioned to the counter guy that the ones I have are noisy. His response was i am doing something wrong, I brought one of them in that had not been installed yet to try and magically it worked fine. They didn't have enough of the Square-D ones so I used that "good" one and boy what a racket!
> 
> Maybe I am doing something wrong........


Are all the contactor coils wired to the same source? Did you check the voltage at the coil


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## JRaef (Mar 23, 2009)

Most people don't realize this, but Definite Purpose contactors are *NOT *UL listed, they are *UR*, or UL Recognized components. What that means is that you CANNOT legitimately use them in the field, they can ONLY be used as part of a factory assembled and listed assembly, or in the field to replace an exact unit. Supply houses never mention that, they sell them because they are cheap. They are the absolute cheapest junk the mfrs can get away with calling a contactor. 99% of them are now made in China or India because there is almost no bottom to the market for those things. In my opinion, DP doesn't stand for Definite Purpose, it stands for Don't Purchase!


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