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Wall mount 16amp 2P+E - with interlock switch?

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Prizen

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Hi all

For wall mounting a 230V 16AMP socket, I will need two sockets ; one for bandsaw the other for P/T.

Is a wall mountable unit with interlocking switch and socket necessary? They are quite expensive when compared to a straight 16amp socket.

This is for hobby only and I would never have more than 1 machine + dust extractor running simultaneously.

Tks
 

Prizen

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Hadn't thought of that , what type of switches have you in mind and would 16amp suffice?
 

Spectric

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Hi there

What bandsaw do you have? I am running a Record BS400 that has a 1500 watt motor and is on a 13 amp plug and no issues, so you may only need a single 16 amp socket for the P/T. If both machines do require a 16 amp supply then as a single user you could just have a single socket and connect as required.
 

Spectric

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Hi all

I will say that unless you are competant and understand the scope of work that can and cannot be done without issuing certs or notifying your local building control then it is worth seeking advice or just get an electrician to do the job. I have seen too many examples of dangerous electrical work and many people do not realise that it only takes 50 mA to potentially put you in the ground. As wood workers we can see those spining blades that want to chop fingers off, we can smell a gas leak but when electricity leaks it is invisable!
 

Prizen

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Shed wired by electrician. 40amp breaker in the house to the shed, armoured cable.

Will fit type C 20amp MCB and run 2.5mm twin&earth to isolator switch. Then out to 16 amp socket.

It isn't rocket science.
 

guineafowl21

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Shed wired by electrician. 40amp breaker in the house to the shed, armoured cable.

Will fit type C 20amp MCB and run 2.5mm twin&earth to isolator switch. Then out to 16 amp socket.

It isn't rocket science.
Should be a 16A MCB protecting the 16A socket. Otherwise, unless the circuit is very long or buried deep in insulation, that should be fine.

You might consider a 30mA RCBO with type C16, unless there is already an RCD protecting the circuit. Sockets should have RCD protection of some sort, and it will give you additional protection in the event of cable damage from rodents/flying tools/etc!
 

Prizen

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I have an N4400 on the way Roy! This needs a 16amp supply.
 

Oddbod70

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40A to a shed! What did you tell the spark you were doing in there :)

The actual connecting may not be rocket science but working out what you safely need to do is a bit harder than it appears. I think thats the point spectric is making.

ive seen some excellent DIY electric stuff done and ive also seen some lethal stuff. Just be careful.
 

Prizen

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It's likely I will move things around a bit, so hardwiring wouldn't be my first choice
 

Sideways

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Shed wired by electrician. 40amp breaker in the house to the shed, armoured cable.

Will fit type C 20amp MCB and run 2.5mm twin&earth to isolator switch. Then out to 16 amp socket.

It isn't rocket science.
It may not be rocket science but it's notifiable and subject to building control. The building control charge for inspecting it will be more than the cost of getting a sparky to install and self certify it.
The cost of a calibrated test meter to do the paperwork is more than the cost of an electrician even if you know what measurements you have to make.

Your responsibility, your choice :)
 

Jackbequick

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Hadn't thought of that , what type of switches have you in mind and would 16amp suffice?
It's not correct to use 20 Amp outlets on a 16 Amp circuit. It stands to reason does it not?...Same issue as with the previous saw connection I an others examined. Your saw may need a motor start breaker or fuse.

Your General Purpose outlets must have 30 mA RCD's. I am unsure of UK but here 15A outlets have a larger earth pin than 10A and 20A have larger pins all around. The idea is to stop people just doing as they please in breach of safety.

As far as 'not rocket science' perhaps it is. A distribution board run in a shed with the main switch to it located in the house is pretty slack. There should also be a sub main switch on the 'workplace' board, clearly marked so a person can immediately see and 'knock-off' the whole circuitry if needed.

It also gives some more safety to people who 'mess around' with shed wiring....thinking it too far to go to knock off the submains....and then when switched-off in the house we have a chance someone will turn it on. No??...well such things happen and sometimes people get fried as a result. If turning off in the house, use a positive lock-out device on the switch/breaker...not just a note or even a tag....

Moving stuff around...That's not a great habit and why you'd have to move a band-saw around rather than sensibly locate it and leave it there is something you might dwell upon. It is also possible to use pendulum socket outlets for other items.


Shed wired by electrician. 40amp breaker in the house to the shed, armoured cable.

I'd permanently connect the saw rather than use a socket. THat's all from me.

Will fit type C 20amp MCB and run 2.5mm twin&earth to isolator switch. Then out to 16 amp socket.

It isn't rocket science.
 

guineafowl21

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The neverending electrical thread!

It's not correct to use 20 Amp outlets on a 16 Amp circuit.
He was proposing to use a 16A outlet on a 20A circuit, the opposite. I suggested a 16 on a 16.

As far as 'not rocket science' perhaps it is. A distribution board run in a shed with the main switch to it located in the house is pretty slack. There should also be a sub main switch on the 'workplace' board, clearly marked so a person can immediately see and 'knock-off' the whole circuitry if needed.

It also gives some more safety to people who 'mess around' with shed wiring....thinking it too far to go to knock off the submains....and then when switched-off in the house we have a chance someone will turn it on. No??...well such things happen and sometimes people get fried as a result. If turning off in the house, use a positive lock-out device on the switch/breaker...not just a note or even a tag...
I would place a bet that the DB in the shed has a DP main switch and some breakers, a so-called garage consumer unit. It’s highly unlikely that the armoured cable is somehow terminated directly into the individual circuit breakers.

It’s very interesting to read someone’s knowledgeable and enthusiastic account of wiring in another country. It’s a bit like someone from a parallel dimension is here giving domestic wiring advice :unsure:
 

Oddbod70

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I’m really not sure I want to post this. It runs the risk of saying it’s OK to do DIY electrics. In some circumstances it is, but in others it isn’t, really it isn’t. The regs are there for a reason, which is to keep you, and those who own the house after you safe.

Note that the rules about what you can and can’t do differ between the UK countries. Having said that in what follows I’m more interested in keeping you safe.

Some things to consider.

Please don’t mess about in the consumer unit. It’s surprisingly easy to get it wrong. Failing to locate the live busbar connected to the bottom of the protective device (the “MCB”) properly. Snapping off or trapping the ring final or radial wires at the top. Sticking different size wires in the same connector . Not tightening the screws properly. Etc, etc. Remember there is nothing protecting you in there except the main house fuse. If you isolate the consumer unit (which you must do) by cutting the electricity board seal and pulling the fuse out, and it goes wrong, the bang will knock you into next week. Accidentally shorting out something protected by a 13A fuse is one thing – shorting out the house fuse, or even the supply :D, is something you really, really don’t want to do! Recognising the dangers comes from experience, which you won’t have.

It’s probably best not to run a cable to a shed yourself. At least not unless you want to read up voraciously on types of earthing system (no, you can’t always “just run an earth wire from the house”), discrimination, and voltage drops. And once you’ve done that there is the entire question of how to safely run the cable. Things like putting in a trench and burying SWA cable properly, clipping it to permanent structures, using and terminating safely.

Then you have to test it. That gear will cost you £500 for sure, plus a lot of figuring out how to use it.

So in short, get a sparks to run you a cable and put a garage consumer unit in the shed. Ask them to give you plenty of space in the consumer unit and install some spare ways (circuits). Chances are they’ll leave a mix of 6A (lighting) , 16A, 20A for radial power circuits and perhaps 32A for power ring finals.

From there on things get a little better. As long as you read up a bit first, adding sockets in a shed is not the worst offence to commit. Use quality fittings. Run the cables safely (plastic conduit), sleeve the earth wires, buy and use a plug in tester (EG a £50 Martindale). Tighten screws and recheck them an hour later. (The little b*****s can unscrew themselves). There are plenty of pictures of good practice on the interwebby thingy.

Finally, please, please be safe. You can’t see electrons but you can sure feel them. If you are not sure what you are doing, then don’t.
 

Prizen

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So, RCBO already installed. I do remember the electrician telling me that the shed can be setup for a lot of power. The armoured cable coming into the shed is large.
 
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