Will retro switch work on modern light circuit?
- Thread starter Welshjeff1000
- Start date
Sponsored Links
Yes, the basic principles of the light switch haven't changed since they were introduced. I can't quite see from the picture, but that looks as though it might be a 2-way switch; obviously if you need 2-way switching it would need to be so.
Keep in mind that these were intended to be wired with conduit entering top or bottom. If you're planning on using it as a replacement for an existing wall switch on a back box, you'll need to sort out mounting and wiring arrangement, possibly by drilling through the back for cable access and blanking off the conduit entry. You'll also need to make sure that the box is earthed; some domestic lighting circuits were run without earths through the 1960's.
Keep in mind that these were intended to be wired with conduit entering top or bottom. If you're planning on using it as a replacement for an existing wall switch on a back box, you'll need to sort out mounting and wiring arrangement, possibly by drilling through the back for cable access and blanking off the conduit entry. You'll also need to make sure that the box is earthed; some domestic lighting circuits were run without earths through the 1960's.
Not clear what contact arrangement that has, but probably could be used if the existing switch is the only switch for the light. If there are 2 or more switches for the light it may not be suitable.
In any case it will not be a 'direct replacement' as that is a surface mounted item which requires conduit for the wiring. An earth must be connected to it. It should be tested before installation as although described as 'unused' it is clearly many decades old.
In any case it will not be a 'direct replacement' as that is a surface mounted item which requires conduit for the wiring. An earth must be connected to it. It should be tested before installation as although described as 'unused' it is clearly many decades old.
Many thanks. I've stripped a wall back to bare brick revealing metal conduit containing the lighting wiring. I hoped to simply keep the conduit and feed it into the retro switch, the tarnished conduit being a feature. It is one switch, one light, in a kitchen.
Best way to earth it, bearing in mind it's not concealed?
Best way to earth it, bearing in mind it's not concealed?
Sponsored Links
What sort of conduit?
And what size? The hole in that switch might not be 20mm.
How is it currently terminated into the existing switch? How is it earthed? Is it earthed? Is it the earth for the lighting circuit?
Photos would be jolly useful.
Normally the easiest way would be to have an earth conductor in the conduit, going to the earth terminal in the back box and the conduit earthed by being bushed into the box. But your new switch appears to be enamelled inside, so you might need a banjo or a piranha nut.
And what size? The hole in that switch might not be 20mm.
How is it currently terminated into the existing switch? How is it earthed? Is it earthed? Is it the earth for the lighting circuit?
Photos would be jolly useful.
Normally the easiest way would be to have an earth conductor in the conduit, going to the earth terminal in the back box and the conduit earthed by being bushed into the box. But your new switch appears to be enamelled inside, so you might need a banjo or a piranha nut.
I'll get a photo of existing set up asap
Many thanks
Many thanks
Do you have an RCD protecting your lighting circuit? I'd not be happy about using a switch with a metal dolly in a steamy environment like a kitchen unless RCD protected.
Ah good point. Although it's away from water sources and near a radiator, I'm thinking it may be vulnerable to condensation build up from water vapour.
There's an RCD on the consumer unit but I'm having doubts over the metal casing too, even if earthed plus RCD.
With kids in the house, I can't vouch for dry hands all the time!!
There's an RCD on the consumer unit but I'm having doubts over the metal casing too, even if earthed plus RCD.
With kids in the house, I can't vouch for dry hands all the time!!
I have some 1930s electrical magazines that have adverts for these switches, Crabtree were still making them in the 1950s.
The switch dolly should be electrically connected to the iron box, provided that the switch module fixing screws are secure.
The switch dolly should be electrically connected to the iron box, provided that the switch module fixing screws are secure.
Last edited:
That doesn't sound safe!!
It's far far safer than many electrical items that have been manufactured in the far east.
I know of a building where these switches are still in use. They are connected to perished rubber wiring in steel conduit, fed from metalclad MEM Kantark fuse boxes. The installation was wired before WWII.
I know of a building where these switches are still in use. They are connected to perished rubber wiring in steel conduit, fed from metalclad MEM Kantark fuse boxes. The installation was wired before WWII.
On the contrary, you want the dolly securely connected to the metal box and the installation's earthing system.
I've worded it better now!
The dolly is only connected through sliding contacts. It would be sensible to check that it has continuity to the metal case.
Some oxidation on the surfaces might have occurred over the years of storage, but a few operations back and forth should soon take care of that.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
