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#71205 - 10/24/06 07:42 AM Need some help with Contactors  
Happi_Man  Offline
Joined: Jun 2002
Posts: 206
Columbus, Ohio - USA
Home Builder is building a model home that they are also using as office space. They want to install a contactor so that they can basically flip two switches and light up the whole house and the office space (garage).

There are 65 cans in the office space, 24 mini cans in the outside soffit and other than that general lighting throughout. Obviously we need to wire switches to code in the case they ever sell the house.

I'm not real sure on what type, size of contactor to buy and how to go about the installation. We've never done anything like this before.

I am assuming I'll have to calculate the lighting load and know how many branch circuits for lighting there will be. All the switches would be tied through and dummy devices installed. Obviously none of the lighting will be able to be fed off of general power outlets i.e. all the lighting will have to be on separate circuits from any receptacles.

Beyond that I'm not completely sure how to go about this. Can anyone give me some advise on this situation and an idea of what type of contactor I might need?

'Prishiate it [Linked Image]

Work Gear for Electricians and the Trades

#71206 - 10/24/06 08:47 AM Re: Need some help with Contactors  
russ m  Offline
Joined: Feb 2003
Posts: 169
A multiple circuit contactor right next to the panel with the lighting circuits looped into it, could be removed when the contractor is done with the home. A set of three ways at the entrances is all you should have to use for the contactor.
These switches could be converted to entry light switches later.

#71207 - 10/24/06 08:51 AM Re: Need some help with Contactors  
Tom  Offline
Joined: Jan 2001
Posts: 1,044
Shinnston, WV USA
You could check out Leviton (and probably others) for home automation products. You can program the light switches for various scenarios, including all lights on, all lights off. This would also allow individual switches to controll lights in a given room.

Few things are harder to put up with than the annoyance of a good example.

#71208 - 10/24/06 12:59 PM Re: Need some help with Contactors  
gfretwell  Offline

Joined: Jul 2004
Posts: 9,124
My wife has several models in her community.
They just brought the lighting circuits into a small cabinet, chase nippled, next to the main panel and installed a couple 3 pole contactors (one pole for each circuit switched), then back to the breakers. They run the contactors off a regular timer.
I don't think they are actually wired any different and these are the general lighting circuits that get switched, receptacles and all. (a lot of the lighting is table lamps anyway)
When the house eventually sells they will pull out the cabinet, timer, pop in a KO plug and move the circuit conductors directly to the breakers for those circuits.
They have had customers who wanted it left alone. These models usually get sold furnished and some people even want the fake food and other knick nacks they have laying around. I often wonder if they change the pictures.

[This message has been edited by gfretwell (edited 10-24-2006).]

Greg Fretwell

#71209 - 10/24/06 08:12 PM Re: Need some help with Contactors  
e57  Offline
Joined: May 2003
Posts: 2,876
Talk about lazy.... Tell them to use the main [Linked Image] No modifications - and cheap...

Mark Heller
"Well - I oughta....." -Jackie Gleason

#71210 - 10/24/06 08:54 PM Re: Need some help with Contactors  
electure  Offline

Joined: Dec 2000
Posts: 4,262
Fullerton, CA USA
A reply for this from "little dog" ended up in the wrong place. Here's his post.

one suggestion is to install a lighting contactor large enough for the calculated load including 25% for any continious loads if this is going to be used in a commercial application. Then you can feed a sub panel that feeds all the lighting circuits.All circuits would be wired to the required size breaker. When you energize the contactor the contacts would pull in and energize the subpanel and any loads being fed from this sub panel. You could just wirenut future switch legs together then at later date if necessary you could install switches. For now you could put blank covers over boxes where future switches are to be installed. At later date you could remove contactor and wire directly to the sub panel. You probably need to check with inspector to make sure this would be acceptable.

#71211 - 10/24/06 09:10 PM Re: Need some help with Contactors  
PE&Master  Offline
Joined: Feb 2006
Posts: 138
put in a 100 amp subpanel with a 125 amp 2 pole contactor in it. the contactor opens both poles to the sub panel. put all the devices to be controlled in the subpanel (basically the lights).

put a switch at front door that pulls in the contactor.

#71212 - 10/24/06 10:02 PM Re: Need some help with Contactors  
JBD  Offline
Joined: Jul 2001
Posts: 599
Be careful when feeding a panelboard with a contactor. Make sure the inrush current of the loads does not trip the breaker feeding the panel. This is a common problem with HID ballasts.

#71213 - 10/25/06 02:29 AM Re: Need some help with Contactors  
e57  Offline
Joined: May 2003
Posts: 2,876
Becareful with 'regular' contactors, i.e. "relays". Although they may be cheaper, it is possible that it will be problematic, especialy if switching panel load that will act differently than say the starting characteristics of a motor.

Most purpose built lighting contactors will be expensive - but with reason. They often will have faster, more postitive, self-cleaning contacts, and either be mecanicaly, or magneticaly held/latched so as not to maintain a coil for long periods of time. Mechanical or certain types of magnetic designs will hold independant of the control circuit - and wont hum like a tranny.... [Linked Image] (So don't put a loud one where you can hear it.) One of my favorite designs was (And I wish I could remember who made it) a 3P-200A that had 6 powerful rare earth magnets under the contacts, and a coil to open it and latch it back. (When you shut off the lights.) When you turn them on, it triggered a release for the contacts to slam shut. It sounded like a gun! Then complete quiet... The same company also had some type of circuitry in their 20A SP lighting relays that only switched at zero crossings of the phase they were on...... Which is a common thing now, but was top-gear for its day. (Late 80's / early 90's)

Mark Heller
"Well - I oughta....." -Jackie Gleason

#71214 - 10/25/06 02:35 AM Re: Need some help with Contactors  
e57  Offline
Joined: May 2003
Posts: 2,876
Oh, another interesting effect [Linked Image] I did this with my video camera controlled motion lights out front.... Wait living room up-lights too. Switch Meastro Dimmers with a relay... You can pre-set all the dimmers, and when the power is off, they keep their settings and state - but fade up to that level when you turn it on, and looks neat. Also reduces that current jump.

[This message has been edited by e57 (edited 10-25-2006).]

Mark Heller
"Well - I oughta....." -Jackie Gleason

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