Low voltage light switch system alternative switches

[888]

I recently bought a house built in 1958 that has a low voltage system and a set of relays to turn the lights on and off.

It's called a Touch Plate system, details on the latest version is here if you are interested:

Home Page - Touch-Plate Lighting & Controls

Solare Preferred Series The Perfect Touch To Any Room! Touch-Plate's customizable Engraving Templates are Quick, Easy To Use, and Easy To Submit! Invisible Fill Text. Invisible Fill Text. Invisible Fill Text. Invisible Fill Text. Invisible Fill Text. Invisible Fill Text. Invisible Fill Text...

www.touchplate.com

I guess it was a high dollar state of the art system back in the day, supposedly saved money on wiring and electricity. My whole house inspector has been around a long time and has seen them before in high end houses in the "old money" section of the city.

Fortunately, I got an old handwritten manual for the system from the previous owner that is pretty helpful in understanding it.

Basically, it appears that the system has a transformer/rectifier than changes household AC current to ~ 30 VDC that runs to the individual light switches and optional 6.3 VDC for pilot lights providing a central display of what lights are on.

The light switches are essentially pushbuttons that send a single pulse to a relay, which connects household AC to the lights to turn them on. The relay stays in position until the switch is touched again and that next pulse switches the relay back and disconnects the AC from the lights to turn them off.

There are control boards and banks of relays from 1958 somewhere in the attic. I can hear them, but I haven't found a way to access them yet. It seems to work fairly well in most locations but some of the switches don't work and a new single gang switch assembly is $16. and the cost goes up from there. It appears some of the board and relay components are getting hard to find as well.

I'd like to just rewire it but and the house does not have conventional high voltage wiring and electrical boxes at the switch locations so I would be modifying walls at every switch location and the walls are plaster with a decorative pattern that would be hard to match.

I have to believe that someone else out there has one of these systems and has either:

A. come up with another current state 30 VDC momentary push button system and cover plates for the switch assemblies
B. changed the Touch Plate system over to conventional high voltage switching with the usual on/off switches.

If you have done either A or B and would like to share what you have done, I would really appreciate it.

Thanks

 

[AC Power]

I am a Master Electrician, in the elec trouble/service industry for 24+ years now (est. Jan 1997). I am the company owner.

I can likely help you with this. This is called "low-voltage switching". They are rare in residential environments, rather, they're found commonly in commercial buildings with large square footages (areas).

Your existing wiring will work just fine for a retrofit to something new, and serviceable. You likely won't be able to switch line voltage and current though....that is, you'll still need a latching relay operated on/at safe voltages. This is no trouble. Easy job to do.

I would encourage you to take some pictures, post them. I would like to see the inside of a wall switch outlet box. Ideally, I would like to see the relay bank in your attic........specific whereabouts unknown?

I can help you with this, we just need to communicate effectively.

 

[888]

Thanks for the reply.

I should be back over at that house this weekend and can take a few photos. Attached is a photo of the manual, a spare switch assembly, and a spare switch actuator for a wall plate.

I pulled one of the wall plate/switch assemblies that didn't appear to be working properly and there wasn't a conventional box surrounding the switches, just a group of low voltage wiring to the pigtails on the individual switches. I found a loose connection to a switch and thought I had the problem fixed but it made no difference so I assume a relay is bad.

I can hear relays in the attic above one of the bedrooms and there is no hatch or easy access to the attic/relay bank. The only access is a small spot cut in the original roof decking planks between the trusses (a two story addition with conventional lighting was added in 1976 and there is a panel in a closet sidewall that opens into this area). Blown in insulation completely covers the bottom trusses so I can't tell where to step to avoid the drywall ceilings. I plan on measuring the access spot to see what kind of plywood I can get in there to walk or crawl on for the short term.

I have a background in low/high voltage machine control/motor wiring and tribal experience/a trade school class in working with residential wiring so I'm not completely starting from scratch. However, if someone has already done this and has a part list for what was used versus me figuring it out, that would be great.

My strong preference would be to junk the low voltage/relay setup and go with conventional high voltage wiring but it looks like that would be difficult. A reliable low voltage system with currently available parts would be good too.

Thanks again for the response, I will post up more information as I have it available.

 

[AC Power]

I thinks its a good call to locate that relay bank in the ceiling, using plywood as a support across the trusses. Too, it seems you are correct in feeling that switching line voltage wiring is difficult as the existing switch control wiring will be of a lighter AWG, and not rated to carry the minimum 15amps that is permitted by the upstream breaker.

To your benefit, your control/motor experience will likely prove helpful.

There are several low voltage systems available, but they all work the same way. One thing is a given though...you have to locate that existing relay bank, take pics. I can help you thereafter. This is not difficult....your not rebuilding the wheel.