I'm very confused by the electrical setup of my 1965-built home.
Around a year ago, a home inspector told me that electrical projects
would be more costly/confusing as the house was built with a "12-volt
The switches are odd as I've looked at the back of a few switches and
they have 3 contacts each. one black/one red and one white. The wire
is stranded 18 or 20 gauge. When you turn any of the switches off or
on, you hear an audible "buzz" which is louder in a few rooms in the
Otherwise, all of my outlets are 120 volt normal outlets, the ceiling
fans and lights are the usual solid 16 gauge romex, it's just the
switches that are odd.
I would like to replace these switches over time with modern two
position 120 volt switches so I can use dimmers, etc. Any advise on
what I should be searching for as to information about this '12 volt
If that home inspector really knew what he was talking about, you might
just have some 12 volt AC relays switching the power to those lights.
The relays could be controlled by those switches.
The buzzing you hear could be from the relays which may have parts which
have gotten worn and a little loose over the years.
Rather unorthodox, but not unheard of.
If you're ignorant in basic electrical apparatus then seek help from
someone who can determine if you do have some relays located somewhere,
find 'em and see what can be done.
Please don't get PO'd at my use of the word ignorant. If you think about
it, no one can be a renaissance man nowadays, and we're mostly all
ignorant about more subjects than we're experts in.
I think I'm a hotshot about things electrical and electronic, but I'm at
a total loss about many other subjects like music and the bible and I
was born without a sports gene. I even have trouble remembering which
two teams played in the World Series this year.
I have no problem with other people's ignorances, it's stupidity I can't
I can remember my parents saying "ignorant" a lot when I was I child.
I didn't know what it meant then and thought it was a dirty word. I
still remember the feeling.
Is seems that I first got interested in electricity (and math) because
it's simple. There's none of that complicated (and weird) stuff often
found in human behavior.
In something like 2+2=4 you don't have to consider things like how
that first 2 feels about the particular shade of pink the + likes, or
the ='s headache and nasty attitude toward addition today. Electrons
don't get lazy and block the wires on Sunday, reciting bible verses
when asked to move.
Most sports are very boring to watch. It would take some sort of
personal involvement to enjoy such.
My grandmother, who I often stayed with, had a lot of lamp and
electrical parts around. Anyway, I've always had a rational idea of
the world, and a preference for things that make sense.
BTW, I'll probably never understand the [deleted] that most people
seem to be obsessed with. It seems to have no connection with the
world around us.
Do a GOOGLE search for GE RR7 or GE RR9.
This was a very, very popular remote control system
in the 60's in upscale homes. A large percentage are
still in use today and the owners like them.
The system allowed multiple control of room lighting,
that is, switches in many locations could control a
single light. Can control outdoor lighting as well.
And individual room receptacles too.
All the switch/pushbutton wiring is low voltage,
which gave the builder flexibility at low installed cost.
The GE relays are still available from distributors
and this company makes replacement models:
There was a forum discussion here:
No, you can't directly replace the switches with 120V
ones or install dimmers. This would entail some
Likely three way switches.
If it is 18 or 20 gauge wire you have some big problems if you are in
NA. What country are you located in?
Interesting, I have no guess. Well maybe one. Maybe that 12V idea
means he determined that you have a low voltage switching circuit using
relays. That would explain the small wires and buzz. That could also be
explained by low voltage halogen lamps.
I hope not 16 gauge in NA that should be at least 14. In 1965 it would
almost certainly be 14 not 12.
As Speedy Jim said these are 12 volt AC switches that operate the
relay contacts for the normal 120 volts AC. There is nothing wrong
with this type of system. It is safer and more flexible. A certain
amount of hum is normal because the solenoid coil that operates the
relay contacts gets magnetized by a 12 volt 60 cycle source coming
off of a transformer. If the solenoid buzzes to much then it's time to
replace the relay.
This is a new system on me and I have a couple of questions for you.
What's the typical size wire running from the low voltage switches to
the AC contacts?
Could you demagnetize the relay or would that mess up the coil somehow?
The system has a 24V transformer (and a diode rectifier).
#18 gage low voltage wire (think bell wire) connects the switches
to the relays and to the 24V power supply.
The "Load" side of the relay (relay contacts) has 120V
with either #14 or #12 "house" wire connecting the relay
to the lights or whatever it is controlling.
"Could you demagnetize the relay"
Does not compute...
These relays are cylindrical and fit into a 1900 box with the bulk of the
cylinder sticking out of the box(the low voltage side). They are a pain in
the ass in that you can't just replace switches with dimmers, but the damn
things seem to last forever. The "buzz" sound only occurs while a switch is
being pressed, then the relay latches into the open or closed position
I have never heard of this but it sounds cool. I am guessing that the
switches are momentary SPDT and the relays latch either way? That would
be incredibly easy to add additional controls to, no need for annoying
three way switches etc... if it works as I imagine, why wouldn't it have
caught on? Too much cost? wouldn't meet current code? just curious
replace "fly" with "com" to reply.
Correct. Momentary switches. The 24V is rectified, so
a DC pulse is applied to one winding or the other of the relay.
The relay then latches magnetically and needs no more input power.
A switch anywhere else in the house can then cause the relay to
A nice application is a large property where outside lights
can be switched on/off from dozens of indoor locations.
Or, a bank of switches can control *any* light in the house from
The system *did* catch on and was quite popular.
But this was 40 years ago!!
I suppose X10 has supplanted it, but the system is
still being promoted in commercial applications where a
minicomputer controls the relays. Endless possibilities!
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