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#141061 05/31/04 09:52 AM
Joined: Aug 2001
Posts: 7,520
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pauluk Offline OP
Member
A few quick pics of some older-style British light switches.

First is a typical 1940s-style tumbler switch, with porcelain (vitreous) back and brown bakelite cover. This is the Britmac "Little Briton":
[Linked Image]

The lower two round holes are the terminals, the center pair have a wax insert covering the screw heads which hold the switch mechanism in place:
[Linked Image]

These have a quick-make/quick-break spring-loaded toggle making them suitable for AC and DC use. Contact ratings are the standard 250V 5A maximum:
[Linked Image]

[Linked Image]

[Linked Image]

#141062 05/31/04 09:53 AM
Joined: Aug 2001
Posts: 7,520
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pauluk Offline OP
Member
Here's a later model, probably 1950s, made by GEC. Unlike the first switch where the cover is secured by two screws top and bottom, this one just unscrews from the threaded center hole:
[Linked Image]

In this one the switch contacts are fully enclosed. The rating is 250V 5A again, but the swtich is a quiet-action type without the spring-biasing, and is thus stamped "AC only." This is the 2-way (=U.S. 3-way) version:
[Linked Image]

[Linked Image]

[Linked Image]

By the way, to give an idea of scale, both of these switches are about 2" diameter.



[This message has been edited by pauluk (edited 05-31-2004).]

#141063 05/31/04 01:58 PM
Joined: May 2004
Posts: 186
A
Member
Remember them well, and the Crabtree lincoln switch mutch the same pattern. Spent many/many hours drilling wooden blocks to match the connection holes. Oh nostalgia tears are starting to well up in my eyes. I can even hear my old mate shouting at me for not getting the holes perfectly in line with the connections. Thank you lord for the modern plate switch.

#141064 06/01/04 01:49 AM
Joined: Jul 2002
Posts: 8,407
Member
Paul,
We used the Round GEC switches here too.
And there are still a lot of them in use here, to this day.

#141065 06/01/04 05:51 AM
Joined: Dec 2001
Posts: 2,492
T
Member
We had those round switches too, they were usually installed on "conical anchors", that's the name for conic wood patresses that are plastered flush in a wall. They usually had a 1/2" center hole for th wires. In walls with crumbly bricks far more reliable than modern plastic plugs.
The squarish one looks weird though. Older switches were completely round and newer ones are square, sometimes rectangular.

#141066 06/01/04 12:04 PM
Joined: Aug 2001
Posts: 7,520
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pauluk Offline OP
Member
Yes, that Britmac with its "rounded square" shape was less common than the plain round types.

As Alan mentioned, the usual method of installation here involved a wooden pattress block, with individual holes drilled to line up with the terminals. The block was then fixed to the wall (sometimes with just a single screw through the middle) with the wires left poking through the holes, and the switch then screwed onto the block.

I have loads of the Crabtree tumbler switches. When I was a kid these were the sort of thing that were being stripped out of older houses for rewires, and I managed to get holds of lots of them for free. They were very handy for my various electrical projects of the time, such as banks of light swiotches for model railways etc.

I'll take some pics of the Crabtree switches next time I have a photo session.

#141067 06/02/04 09:38 AM
Joined: Jan 2003
Posts: 45
S
Member
Heres a few pics of the wooden pattress switch and a few others i ripped out of a job i done a few months back.

[Linked Image from zen23694.zen.co.uk]

[Linked Image from zen23694.zen.co.uk]


[Linked Image from zen23694.zen.co.uk]

[Linked Image from zen23694.zen.co.uk]

Heres a few pics of some old Pyro cable clamps which came from the same job.

[Linked Image from zen23694.zen.co.uk]

[Linked Image from zen23694.zen.co.uk]

#141068 06/02/04 04:35 PM
Joined: Oct 2003
Posts: 289
:
Member
Quote: [Linked Image from zen23694.zen.co.uk]

I am always suspicious to switches with metal handle. I also dont like those little knitter switches, unless they are mounted in a grounded plate.

[Linked Image from knitter-switch.com]

i've seen those (don't know which manufacter) mechanically fail after a high on/off cycle count, shorted pole to pole, and i think they could also short to the housing...

[This message has been edited by :andy: (edited 06-02-2004).]

#141069 06/02/04 05:31 PM
Joined: May 2004
Posts: 186
A
Member
Andy,The Crabtree metal dolly type is usually O.K.it was always fitted in a good quality cast iron box, with the fixings for the switch interior being taped directly into the cast box giving a good earth. (prviding the conduit was sound). Agree with you on the panel type switch have seen a good number of these shorted and blown up even seen them causing the door of the panel to become live because there has been no bonding strap across the hinge mechanism. Never like to see them on 240v systems. You can get a rubber gasket that fits over the switch dolly but they are seldom fitted.Even that does not make me like them. Company called Arrow used to make lots of them.

#141070 06/03/04 05:55 AM
Joined: Aug 2001
Posts: 7,520
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pauluk Offline OP
Member
Andy,
Although most have now long-since been replaced, when I was a kid there were a still quite a few old brass switches left in service in 1920s/30s houses.

Unfortunately, some were not grounded, especially if somebody had used a brass switch as a replacement for one of the types pictured at the top of this thread. In domestic wiring, lighting circuits here were not required to have an earth until 1966.

I've used many of those miniature toggle switches in my electronics work over the years, and they do fail sometimes (the old full-size toggles were far more reliable).

I would always ensure that a metal panel is bonded, not just for safety but also because in many types of equipment it is needed to help shield circuitry and reduce hum.

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