CU's

[studders]

surely a split board is essential in a workshop in order to make sure the lighting stays on when something on the power circuit trips the system.

Rob

Only if you don't like playing the 'Find the CU in the Dark' , lose Ten Points for every 'thing' you walk into game.

I'll be changing my CU soon so, won't have to play that game much longer.

 

[BTR]

I think you will find most if not all CU are now dual RCD protected .

 

[Dibs-h]

If one had a dual CU, the sockets where protected by RCD - you'd be protecting against earthing faults (to my mind - unless I'm totally missing the point on RCD's). But say with a few static machine, couldyou have the machines on spurs with a Fat red button, upstream of the socket or not? By Red fat button - I'm referring to the setup I recall (vaguely) at School - where all the static machines had a red button nearby, which if pressed, cut all power to the machine. I don't think it killed all the machines - just that one. I suppose what I'm getting at is - I can't see any other way of fitting the Red button - except on a spur, which would make all the larger machines go on spurs.

The other way I can see it happening is to induce an earth fault thereby tripping out the RCD and killing the entire circuit - but I wouldn't have thought that's clever. pps:

The reason I ask - is that I'm a little away from electrics and my 8yr is very likely to be spending time in the shop, so don't mind spending a little extra for elf & safety.

 

[studders]

From what I recall Dibs, the Big Red Button did kill all the machines, not just one. :duno:
When you come to do yours it might be an idea to have electric key locks on each machine, as well as the 'kill all' button. You know how young uns like to fiddle and press things.

 

[Dibs-h]

From what I recall Dibs, the Big Red Button did kill all the machines, not just one. :duno:
When you come to do yours it might be an idea to have electric key locks on each machine, as well as the 'kill all' button. You know how young uns like to fiddle and press things.

If it killed all the machines - then I can see that if you wired a red button to induce an earthing fault - that would cause the RCD to trip and kill the entire circuit. But would that be a clever way of doing thing? Also is that allowed?

IIRC some of the Red buttons had key locks in them that required the key inserted for it to deactivate - that would do nicely as in the case of leaving for the day, etc. you remove the key and it goes into kill mode, killing the entire circuit.

'Suppose will have to wait for Bob when he comes back - unless there's some sparkies about.

 

[WoodAddict]

You could hard wire an Emergency Stop button (red mushroom shape thing you speak of) into the flex of the power lead. This would kill the power to the indivdual machine. There are hundreds of different typs on the market. You just need to make sure that they are rated to match the power of the machine that you attach it to. (wattage and/or current)

Just an example - http://cgi.ebay.co.uk/Emergency-Stop-Bu ... 2a05ab3e50

There's a million ways to add safety features into the workshop with regards to cut-off switches but if you can't find stop buttons that are rated high enough then you have to get into relays and contactors and control circuits. Again, this is doable but wouldn't be worth the time and expense for a small home workshop.

This would be with the kind of thing that you were speaking of with the keyswitch http://cgi.ebay.co.uk/Crabtree-Mushroom ... 3cab500cd6 this particular one requires the contact block for the back of the switch and then a small box to house it all in.

Have a look at Maplin/RS Online/CPC etc....

They all have online catalogues. Failing that, write a list of the machines you would like to protect and their current/power rating and I'll have a look around when I get 5 minutes and find the things you want.

Hope this helps
Paul (Sparkie)

 

[Dibs-h]

Thanks Paul - most of my kit wouldn't go past 16a on the whole, so I wouldn't have thought it would be an issue.

I suppose at this point I'm just getting my head round the "how to do it" aspect.

For individual m\c's , as you say - one could put the stop button in the lead to the machine effectively, but how would you kill the entire circuit upon the press of one emergency stop button?

 

[jlawrence]

I quite fancy having an emergency stop button in the shop.
My first thoughts were to put one the main feed into the shop - before it gets to the CU - to give a convenient way of killing all power when leaving, but it would also then kill power to the alarm system.
As my sockets are wired in as radials (as opposed to a ring) I suppose I should really put an emergency stop on each radial that I want one on.
TLC direct have the non key ones for £2.50 but don't start current ratings

 

[matt]

Why have one emergency stop button? You kinda have to be near it for it to be effective which, to my mind, dictates that you should have an emergency stop button within reach of the machine when using it. All my machines have a stop button already. Even if there's a couple of you in a workshop, you're more likely to run toward the person in trouble and hit the stop button (or pull the plug) than you are to potentially go in the opposite direction to hit a stop button.

I can understand in a school where you have a room full of students. You hear a scream and just want to go to one place to hit one button and then find out which one is bleeding.

 

[MickCheese]

The TLC one is 3 amp

Mick

 

[WoodAddict]

Fitting one on each radial is the only way, though as said above - Why kill everthing with one switch? If the area is seperately alarmed then I'm assuming that it has it's own door so just lock it. The only real use of a Stop button is for emergency. It wouldn't do it any good using it all the time as it's not design with this in mind.

What about putting a lockable cupboard around the fuse board? Though you shouldn't have it lockable when any of the breakers are on for obvious reasons.

For an Emergency stop it needs to be local, most machines have a big red off switch anyway as they are built to their own regulations that would cover the safety aspect of it. For an accident like a leak or spillage, an RCD would shut the whole lot off. Maybe the focus should be more on blocking the access to the workshop rather than making it safe once a child (or other) gets in there. You can't put an emergency stop on a sharp chisel or a stanley knife! - Just my opinion though!

Paul

 

[jlawrence]

If the workshop was just that then it'd be fine restricting access. But unfortunately it has to store a lot of swmbo's gardening stuff and bikes as well.
I suppose I could just pop the breakers to stop machines being inadvertently turned on - just that a big red button next to the door on the way out would be so easy

 

[Dibs-h]

Fitting one on each radial is the only way, though as said above - Why kill everthing with one switch? If the area is seperately alarmed then I'm assuming that it has it's own door so just lock it. The only real use of a Stop button is for emergency. It wouldn't do it any good using it all the time as it's not design with this in mind.

What about putting a lockable cupboard around the fuse board? Though you shouldn't have it lockable when any of the breakers are on for obvious reasons.

For an Emergency stop it needs to be local, most machines have a big red off switch anyway as they are built to their own regulations that would cover the safety aspect of it. For an accident like a leak or spillage, an RCD would shut the whole lot off. Maybe the focus should be more on blocking the access to the workshop rather than making it safe once a child (or other) gets in there. You can't put an emergency stop on a sharp chisel or a stanley knife! - Just my opinion though!

Paul

I'd be looking to put one within reach of each static machine - the only reason the thought went onto killing the circuit is that Studders recalled that's how they operate in schools and I couldn't be sure.

I'd only want the button\s for emergencies and perhaps if they are key operated switches - no "unauthorised" powering up of kit. Chisels and stuff - to a 8-10 yr old, they know what sharp is and the consequences. But a machine with a "on" button - curiosity would almost insist they press it.

(Any) one button killing the lot might be of interest in that if a youngster (say a teen) is using one machine and the adult another - if for any reason the teen pressed the emergency button, the adult may not know due to his\her machine (or whatever) still running. I know it's unlikely but as I said earlier - I'm just exploring the "how" to do it aspects.

I get the impression that one could (probably will) end up with a ring of sockets and a radial thingy for static machines (or commando sockets) going back to different breakers.

Also - I don't think anyone answered the question, in say a case of a ring\radial if multiple emergency buttons existed and they were actually wired to induce an earth fault - i.e. trip the RCD and kill the entire circuit\radial - is that an acceptable way of doing it or illegal under 17th Regs?

Cheers.

 

[WoodAddict]

Also - I don't think anyone answered the question, in say a case of a ring\radial if multiple emergency buttons existed and they were actually wired to induce an earth fault - i.e. trip the RCD and kill the entire circuit\radial - is that an acceptable way of doing it or illegal under 17th Regs?

Cheers.

I would say - Illegal? - No! Possible? - Yes! Acceptable? - That would depend on the individual. I would personally not install any such switch as it would be bad practice and as it would be a bodge job. I don't know of any switch on the market that is desgned to do this so I wouldn't guarantee it. I may be wrong but this is how I see it.

Just another point, tripping the RCD would only throw the main switch, not the individual breakers. Hitting one switch on the way out would be no easier than switching off the main breaker on the way out.

 

[studders]

The point of having a 'One Button Kills All' setup in the school was , I think, so that the Teacher could, on seeing someone doing or about to do something dumb, kill the power from wherever he was. I'm sure there was more than one switch that could do that, located around the Room.
In the home workshop I think the Key Lock Switch approach probably gives the best solution. The machine could only be used under supervision, assuming the key wasn't left in place.

 

[jlawrence]

Hitting one switch on the way out would be no easier than switching off the main breaker on the way out.

It would for me as my CU is in the top corner of the shop opposite from the door and not the easiest of places to reach.

 

[Dibs-h]

Just another point, tripping the RCD would only throw the main switch, not the individual breakers.

Ahh! Hadn't realised that - thought it would pop the individual breaker for some daft reason. Should have realised that RCD protection is not at the individual breaker level.

Be interesting to find out how the "hitting any one emergency button - kills all machines\sockets" works. I suppose if you were using a dual RCD panel - then you could run lights, alarm off one side and radial\ring circuits off the other side. That way hitting any emergency button would kill all machines\sockets - without bothering the lights\alarm.

And as it's for proper emergencies - you should hopefully never have to get to the panel to reset the RCD.

Will have to have a ponder on this and the switch (key operated) method to kill individual machines.

If you come across a method to kill all m\c's without fudging things - be interested to know.

 

[RogerS]

.... Should have realised that RCD protection is not at the individual breaker level.

....

It is if you protect each circuit with an RCBO.

Much as I think the issues raised are merited, I can't help thinking that, in the absence of a qualified electrician, we're clutching at straws as to what is the best way/what is available.

 

[Dibs-h]

.... Should have realised that RCD protection is not at the individual breaker level.

....

It is if you protect each circuit with an RCBO.

Much as I think the issues raised are merited, I can't help thinking that, in the absence of a qualified electrician, we're clutching at straws as to what is the best way/what is available.

Rog

Ta! Will look into RCBO's.

WoodAddict (Paul) is a Sparkie.

 

[RogerS]

WoodAddict (Paul) is a Sparkie.

That's a relief!