Latching Relay

Thread Starter

DYLH

Joined Aug 13, 2013
28
Hello- I have a curiosity about how the lights in our home work. I'm familiar with 3- and 4- way switches, but I know that isn't what we have in this case.

We are in europe living temporarily. There are latching relays (line voltage) in the power panel, and momentary contact switches. E.g., for the lights in the basement there are 4 switches w/ temporary contact.

In some cases, there are 2- switches that can be used to turn on or off the light in a particular room/corridor.. in other cases, there are 3.

I'm curious how this is all wired for a given 'light'... I've searched google and through this forum, and haven't stumbled across what I would expect... could someone 'dumb it down' for me, and provide a simple diagram?

Thanks much.
 

MaxHeadRoom

Joined Jul 18, 2013
28,576
A little more is needed, are you saying all these switches you refer to are momentary type, rather than the usual maintained?
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
28,576
But is a respective momentary switch also used to turn the light off, IOW, Toggle action?
Not sure of the thinking behind using this method?
Unless they automatically turn off after a certain time delay?
Max.
 

Thread Starter

DYLH

Joined Aug 13, 2013
28
Perhaps... also, makes it a lot easier to 'draw'... don't have to keep track of all those tick marks on the CAD plans ;). The method seems pretty pervasive in europe. Since they pull cables, instead of wires, perhaps makes it less inexpensive to install labor wise, as they don't have to have extra stock of different types of cables.

Dunno.. to each their own, I guess.
 

BillB3857

Joined Feb 28, 2009
2,570
I took an old X-10 appliance module apart and it uses a solenoid pulsing a ratchet wheel. The wheel has a cam lobe which operates the movable contact of a relay. Each pulse of the solenoid advances the cam and alternates OPEN-CLOSE-OPEN-CLOSE on the switch. Maybe you have something similar.
 

gerty

Joined Aug 30, 2007
1,305
Sounds like you have what we used to refer to as "low voltage control lighting". It was used in the US in the 60's and it's claim to fame was the reduced initial cost of wiring. It used low voltage, latching relays, mounted at either the fixture box or the main panel.The relays were a dual coil latching type, typically 24 vac.
I still have one on one of my old wiring trainers.
 

Thread Starter

DYLH

Joined Aug 13, 2013
28
Thanks, odinhg! Yep, looks like the 'TL' is the same type of device... the schematic there is right in line with what I was suspecting.
 

MaxHeadRoom

Joined Jul 18, 2013
28,576
It appears the main object is for low current switching device to control 32+amp lighting circuits, where many illumination points are fed from single low current switches.
The 1 pole and 2 pole devices can be stacked together to form multi-pole distribution.
Max.
 
Last edited:

sheldons

Joined Oct 26, 2011
613
heres how it is wired over here in the uk-240v ac supply -2 way switching using twin and earth and 3 core and earth-very easy with an additional switch to provide 3 way switching....no relays required.....
 

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