Mid twentieth century wiring - relays

[WobblyHand]

I'm dealing with an estate and trying to sell the home and property. There seems to be an issue with some of the lighting circuits, and one of the AC zones. The lighting circuits appear to go through relays. Now since the house was built in 1956, I think some of the relays have gone to the big race in the sky. (Relay race in the sky... Weird, I know.) But I don't know where these relays are! I can hear them attempting to actuate, so I can get a general location, but I know nothing what to expect. In general, I'm reluctant to cut into things, simply because then I have to repair it and make it look ok again. If they were in a wall, I'd have to repair the wallpaper, or if in the ceiling, maybe even have to paint the whole darned ceiling.

Are these relays sold anymore? (SquareD/Schneider Electric?) If not, are they repairable? How were they typically installed? If I'm lucky I might have access to some of these relays via the attic. Hmm, maybe the relays are powered off a low voltage transformer - at least I can look for one and check the voltage. I remember some doorbell like transformer in the basement. I do hear them clunk, but the lights don't go on. There's too many lights for it to be the bulbs, but that's a possibility as well.

If anyone knows something about these kind of circuits and how they were done, it would be helpful. Thanks.

 

[matthewsx]

If you’re trying to sell the house I’d turn it over to a licensed electrician.

Either that or disclose to buyer and let them deal with it.

Too much liability to DIY IMHO.

John

 

[WobblyHand]

If you’re trying to sell the house I’d turn it over to a licensed electrician.

Either that or disclose to buyer and let them deal with it.

Too much liability to DIY IMHO.

John

I'm only investigating the issue. Locating the relays. Checking if contacts are shot, stuff like that. If the relays are replaceable (plug-able), I might do that. I'm not rewiring. I have done repair at my home, added circuits and outlets, but know when to let an electrician to do the work. They know far more tricks than I do. On the other hand, they can take some shortcuts which are messy and prevent further access in a panel. I've had both good ones and bad ones. (Same with plumbers.)

As for disclosing to the buyer - they can clearly see that the lights aren't working, because it's dark. If possible, I'd like it to be light - as cheaply and legitimately as possible. Personally, I'd like to let someone else deal with it - but so far the house has had no interested buyers, at least at FMV, only tear down speculators. So I need to spruce up a few details to make it feel like one can just move in. If I didn't need to sell the house, I'd be perfectly happy to live there, 98% of it is very, very nice. (House is too large. Can't afford the property taxes.) Darkness doesn't make a good impression in a hallway.

 

[RJSakowski]

My aunt and uncle down in southern IL had a house of similar vintage that used relays for switching house power. The benefit was that you could use as many control points for a circuit as desired.

As to locating the relays, IIRC, there are now devices that can trace a live circuit through walls. If you de-energize the relay, you could trace the wire to the point where the line is dead which should tell you where the relay was. If you hear the relay activate but the circuit isn't powered, it may just be a case of corroded contacts, in which case, dressing with a contact file should put you back in service.

 

[WobblyHand]

My aunt and uncle down in southern IL had a house of similar vintage that used relays for switching house power. The benefit was that you could use as many control points for a circuit as desired.

As to locating the relays, IIRC, there are now devices that can trace a live circuit through walls. If you de-energize the relay, you could trace the wire to the point where the line is dead which should tell you where the relay was. If you hear the relay activate but the circuit isn't powered, it may just be a case of corroded contacts, in which case, dressing with a contact file should put you back in service.

Do the live circuit tracers work on low voltage, or just line voltage?

 

[RJSakowski]

Do the live circuit tracers work on low voltage, or just line voltage?

Just line voltage, I believe but you should be able to trace the line to the relay.

 

[WobblyHand]

Meant to write more. Where were the relays typically put? Walls, ceilings? I hear the relays activating, but no lights go on.

 

[WobblyHand]

Just line voltage, I believe but you should be able to trace the line to the relay.

So not 26VAC?

 

[WobblyHand]

I'll try to locate a live circuit tracer.

 

[Boswell]

two ideas.
1. if you can hear the relays activate, then how about a stethoscope and then hunt for the loudest location
2. There are low voltage signal tracers, often used on network wiring. you connect to one end of the wire (de-energized) and then touch the probe to the other end, you get squeal when you touch the correct wire. this of course will not work for you as you don't have access to both end, however, I have found that you can get some tone if you get close. Close as in an inch of the wire so there is a possibility that it might work.

Tone Tracer on Amazon