No doubt you've seen them before on eBay; "barn find, industrial, steampunk, retro, cool, rare..." light-switches. Typicall...
No doubt you've seen them before on eBay; "barn find, industrial, steampunk, retro, cool, rare..." light-switches.
Typically made by Crabtree or Walsall, cast-iron cases with toggle switches. Sometimes they have a circular knob instead of a toggle (although this is a "conceit" the knob actuates the toggle).
Almost all of them will have one or more conduit entry points and quite often will still have a remnant of the original conduit still attached.
They're appealing, different and a nice counter to the oh-so bland permutations of the standard light switches we've all become accustomed to.
Of course there are some "challenges":
- They will have no earth connection/terminal - bad news
- They will not have a rear entry point for cabling because they'll be designed to be connected to conduit
- 2-way switches needed for your typical light-switch at the bottom and top of the stairs are uncommon to say the least
The thing is if you're going to buy into this look, you really do need to commit to it and understand that it's not really just a case of throwing the thing at the wall and hoping it sticks; there are regulatory, functional and aesthetic details that need to be covered. So in the spirit of openness we'll go through the process to install one of these barnfindretroindustrialsteampunkcool switches into a home environment.
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| Our subject for today; the retro, industrial light switch |
Regulatory...
These switches hail from a time when children swept chimneys, threaded live weaving looms, men dying building things, machining things or digging things up was an "acceptable cost of doing business" - in other words a less risk-averse age. They also hail from an environment alien to the domestic home; the factory.Modern wiring regulations would almost certainly make producing such switches impossible and when using them in the home there's really two key things to consider; earthing and cable ingress/egress. Having the switch earthed is essential, that tiny bit of copper is the difference between the MCB or RCD tripping or you catching fire after your heart has stopped - take your pick, we know which we'd prefer.
For this install we drilled and tapped the casing internally and installed an earth "tail" - crimped connection, bolted into the casing with incoming/outgoing earth connections connected to it. This is both a mechanically and electrically "sound" approach. The earth is not going to fall off and it's not going to disintegrate.
Cable ingress/egress (or in other words power in, power out) has ramifications here and in the aesthetic considerations. Originally the switches would be attached to conduit (rigid steel, iron pipe through which the cables, often individually, would run). The conduit would be threaded and the switch screwed to both it and the wall ensuring a very strong mechanical connection that would also afford good physical protection. In some installations where there was an explosion risk the conduit and all terminations would be specially rated and installed.
There are 3 ways to get the cables in and out in the domestic environment which in order of desirability are:
- Stick them through the hole in the top/side/bottom where the conduit would have been; this is bad, very bad, not only does it look appalling but it also leaves a circa 20mm hole in the switch for you, your children or an inquisitive cat to stick a finger, paw, screwdriver down - don't, just don't
- Drill the rear of the case to allow the cables in; when combined with a blanking plug for the conduit hole(s) this is ok. Just remember to deburr the hole in the cast iron
- Use conduit, like they were designed for <<< This is the option to go for if you can. This approach gives you all the advantages of mechanical security, physical protection, elimination of the 20mm hole to stick hands in etc whilst also "committing" to the look which leads us into...
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| Industrial switch with conduit triptych |
Aesthetic...
You've made the decision that these are the right switches for you, you like that industrial look and then you start to doubt yourself and before long you screw the switch directly to the wall, hidden away almost apologetically and bodge the cable entry and end up questioning the whole thing. |
| Brass stand-offs to allow the switch to sit proud of the substrate |
The threaded conduit connections will typically be 3/4" conduit, modern conduit is typically metric M20 (20mm) or M25 (25mm). You can buy adapters that allow you to go from M20 female to 3/4 male conduit. You can also buy dies and taps to make your own (this is what we do and allows us to machine those brass adapters you see in the pictures). Be mindful that M20 and M25 taps/dies unless specifically indicated "conduit or fine" will NOT be the right ones, the thread pitch will be wrong.
You can buy the conduit itself from electrical suppliers (they will supply to the public as well as the trade) be warned it's typically supplied in 3m lengths and threaded both ends. If you cut it down (which you almost certainly will need to do!) you'll need to be able to thread the cut end.
The same suppliers will offer a range of fitting accessories including clips, bends etc - you may not need any of these; typically we use a single vertical run into the ceiling void.
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- Warning!
- Finally back to safety; electrocity is great, without it our world be a darker place in so many ways BUT it can kill you. If you have any doubt at all about what you're doing just stop. It's not worth it, really it isn't - you can't appreciate your cool stuff if you're dead. These switches will have been reclaimed, you don't know how well that was done, whether they've been tested - check or get someone to check for you; remember if it goes wrong it may not be you who experiences the "thrill" of 240v.
