Contactor switching in residential lighting

[Fred B]

I have a new residential remodel job that currently has most of the lighting control on contactor switches. Owner is looking to have a lot of changes to the lighting placement and number. I've seen a few in some commercial venues but never in a residential and I have very little experience with these. To meet AFCI requirements how would I proceed or what should I recommend? Will AFCI create a conflict with the contractor switches? Should I recommend rewire to a more "normal residential" wiring/switching method. To complicate thing circuit panel is an old Westinghouse 200Amp. Some of the brakers feel "mushy" when turning them off and on, no strong "snap" off/on. Do they even make AFCI for a Westinghouse panel? Haven't opened up the contractor panel but it is an old GE. Any insights would be welcomed. Thanks

 

[hillbilly1]

Probably old LV GE relays, shouldn’t make any difference with the arc faults, it’s just a low voltage driven contact.

 

[hillbilly1]

Probably something like this;

 

[kwired]

"Touchplate" is another name that was once out there.

Westinghouse BR series was acquired by Eaton, current Eaton BR breakers are likely listed to go in that Westinghouse panel, unless maybe it is something other than the BR series.

 

[Jerramundi]

AFCI isn't required on the control circuit... I don't think. Unless it's 120V which I highly doubt it is in your case. Probably a low voltage control circuit like @hillbilly1 said. You would only need to AFCI protect the power circuit.

I'm curious myself if the power circuit closing would produce an arc recognizable by an AFCI.
I did a little search and can't find any complaints of lighting contactors or relays malfunctioning on an AFCI circuit.

 

[Fred B]

AFCI isn't required on the control circuit... I don't think. Unless it's 120V which I highly doubt it is in your case. Probably a low voltage control circuit like @hillbilly1 said. You would only need to AFCI protect the power circuit.

I'm curious myself if the power circuit closing would produce an arc recognizable by an AFCI.
I did a little search and can't find any complaints of lighting contactors or relays malfunctioning on an AFCI circuit.

That's kind of what I was wondering if the contractors open/close cycle would create that arc signature to cause the AFCI to trip. The contractors activating are quite loud, can hear them upstairs from basement where the controls are. That made me wonder about any arc signature from the contractors.
I knew the control circuit looks to be about 24V based on wire size (haven't metered it yet) so wouldn't need to be AFCI, but lights are standard 120V, that would need to be AFCI.
This system is way bigger than any I've had experience with before, control panel almost twice the size of the breaker panel. Anything special I should be aware of in dealing with this size, contactor panel, it is still a single phase 240V 200A main panel? The biggest I've delt with before was 3 circuit 10 contactor panel.

 

[hillbilly1]

It would have the same arc signature as any regular switch, instead of human movement to close the switch, electricity through electromagnetism closes it. Same type of contact.

 

[Jerramundi]

It would have the same arc signature as any regular switch, instead of human movement to close the switch, electricity through electromagnetism closes it. Same type of contact.

I was thinking along the same lines - that it might be similar to that of a normal mechanical light switch.

Maybe a better way to approach this particular question would be to ask how this particular arc signature (i.e. that of a lighting relay/contactor and/or a standard mechanical switch) differs from that of a parallel or series arc in a conductor or set of conductors..

 

[ActionDave]

Those GE RR systems are some of the best lighting control systems ever made. They are rock solid, versatile, simple to operate, and you can still get parts for them.

There is nothing mystical and there is nothing that is going to make an AFCI trip. It's just a box where all the switchlegs in the building go to and there is a bunch of latching relays that fire and turn lights on and off.

 

[Fred B]

Those GE RR systems are some of the best lighting control systems ever made. They are rock solid, versatile, simple to operate, and you can still get parts for them.

There is nothing mystical and there is nothing that is going to make an AFCI trip. It's just a box where all the switchlegs in the building go to and there is a bunch of latching relays that fire and turn lights on and off.

Thanks, that's good to know that parts are available. Now do they offer switches that looks more like traditional wall switches? I have multiple sp and 3ways that need to replace and move as a result of changes being made to room layouts. Owner would like a more traditional look.

I'll get some pictures of the existing layout.

 

[kwired]

Thanks, that's good to know that parts are available. Now do they offer switches that looks more like traditional wall switches? I have multiple sp and 3ways that need to replace and move as a result of changes being made to room layouts. Owner would like a more traditional look.

I'll get some pictures of the existing layout.

They generally were SPST momentary contact switches. You could wire as many as you want in parallel to one another to get multiple switching locations. The relays were an impulse type relay meaning input signal changed the state of the output, but it remained latched in that state until the next input signal is received. I believe many were only rated for a momentary input signal and if you had a stuck switch situation a continuous signal may burn out the relay coil.

 

[Jerramundi]

There is nothing mystical and there is nothing that is going to make an AFCI trip. It's just a box where all the switchlegs in the building go to and there is a bunch of latching relays that fire and turn lights on and off.

Yup. I was going to say a complete remodel to a more standard system might be a pain in the butt because all the switch legs go to the contactor panel. I'm still curious about the differences between (1) the arc signature of a standard switch and relay/contactors.. and (2) a series and/or parallel arc(s) on conductors. If anyone knows about this, please throw down!

 

[Jerramundi]

@Fred B One other thing to stay mindful of is the rating of the contactors as you add lights, if you keep the existing system but just modify the switches, which it sounds like you will be doing.

 

[Jerramundi]

@ActionDave This might be a dumb question, but could you just install standard toggle/decora wall switches? The are rated up to 120V. The first issue I see with this, other than the question of whether or not they would work with low voltage, is the listed rating of wire size to terminal terminations... but could you just splice on a #14 AWG to the LV wire in the switch box and hook up a standard switch?

 

[Jerramundi]

@Fred B Found this product sheet from Leviton for Industrial and Commercial Grade Low-Voltage AC/DC Switches in Toggle/Decora style... but they look pretty expensive. Not sure exactly how they differ from your standard switch aside from the listed voltage rating.

https://images.homedepot-static.com/catalog/pdfImages/8c/8ca7b264-a683-45bd-bab5-5bb28ebdb069.pdf

 

[hillbilly1]

@ActionDave This might be a dumb question, but could you just install standard toggle/decora wall switches? The are rated up to 120V. The first issue I see with this, other than the question of whether or not they would work with low voltage, is the listed rating of wire size to terminal terminations... but could you just splice on a #14 AWG to the LV wire in the switch box and hook up a standard switch?

They would need to be momentary contact, but are available.

 

[hillbilly1]

It will also need to be single pole double throw.

 

[jap]

That is unless you install a LV relay prior to the 24v switchleg reaching the inputs on the lighting control panel.

In that case you could use a standard maintained SPST on/off switch to control the coil on SPDT relay and let the relay toggle the latch/unlatch switchlegs to the lighting control inputs prior to the coil clearing contacts.

JAP>

 

[jap]

If it has coil clearing contacts that is.

JAP>

 

[synchro]

They would need to be momentary contact, but are available.

This is an example of a SPDT momentary contact switch which should be suitable:

56081-2W

www.leviton.com

Other options are listed on pg. 2 here:

https://www.leviton.com/en/docs/Q-1054_Specialty_Switches_Sell_Sheet.pdf