Create a safe switch that will trip RCD

[Dean Longstaff]

So hi everyone, i have alot of electrical items in my room upstairs. And if anything were to fail i would like a switch that would turn everything in the house off. If i were to have a red emergency stop button (normally open) and connect it to a plug so that the ground wire and neutral connect when the button is pressed, would this trip the RCD in the fuse box? Also would it be safe? If not is there any safe ways of doing this? Thanks

 

[DuaneMHunt1976]

Go to bed,!!

English is forever changing, as it isn't a royal or set in stone.
It is a gutter speak by then people. Mixture of Latin Danish German and others have come here, so you need to keep up with it.
I don't want people playing with live wires personally.


So you help them do it


If you don't want the house RCD to turn off then have the room on its own RCBO

 

[kingeri]

Deliberately creating a neutral to earth fault? Really? I've heard it all now. How utterly ludicrous. Is the supply TN-S, TN-C-S or TT? Creating a fault like this may seem harmless but it could under certain circumstances create a very dangerous situation, just think what might happen if the RCD fails to operate at the same time as a break in the neutral out on the street.....

 

[Darkwood]

We need to understand the reason why you want to trip the RCD to the whole house if you have an issue within a certain room and what the hazards or risks are in your set-up and use as it is, although its not the usual place to put such a E-Stop system , what is required is a risk assessment. The results of the risk assessment will go most of the way to explain the system you require to do what you need, it is always best to limit any deliberate power cuts to only the area, room, outlet or load that needs to be disconnected and it also needs to be shown that losing power through a deliberate action does not provide a greater hazard than say keeping the power on and controlling the situation like in some kinds of machinery be it industrial or benchtop.

When you crash the power at home you have to remember that this can cause other issues like electronic goods failure due to the transients that can be experienced with power failure hence the action to stop power should be as local as possible.

Getting on to the act of using a deliberate fault to action a RCD to achieve this is definately a no no, unless you use a device that has been specifically designed to do this with the use of a remote action point to it.

There are no cheap solutions around this and the real cost would be guided by the risk assessment, I assume you want to do this to prevent risk or damage to property or persons, both of these do require recognised methods to be compliant of which creating a deliberate N/E fault on a RCD is not one of them as it isn't fail safe on numerous levels.

I'll keep the thread open to allow response from the OP but if the nature of that response is not to realise after the various responses that this is not a good idea and should not under any circumstance be done as any kind of safety set-up or even as an experiment then the thread will be closed, the rcd should only be deliberately operated by recognised methods usually done in routine testing through action of the test button or the use of test equipment.

 

[Dean Longstaff]

Okay, well how does an RCD trip in my consumer unit? What electrical fault occurs for it to trip? Like sometimes my irons break over time and trip it, how does it trip?

 

[Darkwood]

Okay, well how does an RCD trip in my consumer unit? What electrical fault occurs for it to trip? Like sometimes my irons break over time and trip it, how does it trip?

It monitors earth leakage by using a finely tuned magnetic balance to hold itself in the on position, if the current going down L is not the same as returning down N and this difference is over the trip threshold set by the device then the device operates, basically any current that doesn't return must have found an alernative route and in the domestic realm this will nearly always have found a path to earth ... if loads are very low the action of shorting a N/E link may not have any effect on the RCD and this is a common fault where the RCD only operates when larger load is added to any circuit if one of them it protects has a N/E fault especially a high impedance fault, this can be a bugger to realise the issue if your new to the problem.

 

[Dean Longstaff]

It monitors earth leakage by using a finely tuned magnetic balance to hold itself in the on position, if the current going down L is not the same as returning down N and this difference is over the trip threshold set by the device then the device operates, basically any current that doesn't return must have found an alernative route and in the domestic realm this will nearly always have found a path to earth ... if loads are very low the action of shorting a N/E link may not have any effect on the RCD and this is a common fault where the RCD only operates when load is added to any circuit if one of them it protects has a N/E fault especially a high impedance fault, this can be a bugger to realise the issue if your new to the problem.

Okay, so if i were to use a transformer and pass 12v down the earth wire would that work, or does it need to be more than 240v or is it controlled by current and not voltage?

 

[YoungBart]

Why would you want to trip the whole house? It would be as stated much easier and safer just to interrupt the supplies you require tripping as opposed to everything.
Also what electrical equipment is it you require to interrupt the supply to? as this could effect your choice of emergency stop.

 

[Darkwood]

Okay, so if i were to use a transformer and pass 12v down the earth wire would that work, or does it need to be more than 240v or is it controlled by current and not voltage?

Current or Voltage - read my last post.
Firstly as stated before, this is not an optional method to drop your power out no matter how you decide to create the fault, you could do with looking up how rcd's work and understand them first as a theoretical excercise and also how your typical isolating transformer works to answer that query.

I would be happy to help you if you are genuinely interested to sorting this out in a compliant method but I would need a lot of info to do some sort of risk assessment although I suspect you won't need any kind of complex system here.

 

[Marvo]

What you're suggesting could work in theory but there's several good reasons not to do it. You're highly likely to have a less safe installation. If you need sockets with an emergency stop then get an electrician in to install a circuit specifically for this rather than a whole-house arrangement......and no, the transformer idea won't work or be any more safe.

 

[Adam W]

The idea is to minimise disruption in the event of something tripping out - separate circuits so for example if there's a fault with the immersion heater while you're out just that will trip and you'll get back to no hot water, not no hot water and a defrosted freezer. Or if you're doing your nefarious experiments upstairs and it all goes pear-shaped, the specific problem will be isolated and not trip out all the lights so you'll still be able to see to get to the consumer unit to reset the circuit without breaking your neck falling down the stairs on the way.

What exactly is it that you're trying to do? I can't think of any situation where an emergency stop button located in an upstairs bedroom to isolate an entire house would be the safest thing.
If you're after a button to turn the telly off downstairs to annoy your sister when she's watching Hollyoaks the circuits are normally segregated across different RCDs for the reasons I've mentioned, so this won't work.

 

[Marvo]

Okay Dean, we're quite rightly getting reports requesting this thread is closed because what you're proposing is unorthodox and highly likely to be outside the regulations and unsafe.

Instead or pursuing the idea and flogging a dead horse, maybe request guidance on a more safe solution.

Here's what I had to say in the Staffroom about this thread;
It's a dangerous arrangement but I'd rather he gets numerous replies telling him it is and hopefully he'll get the message. I think he's genuine, as in he's not trolling, he's just got a bad idea and would probably benefit from guidance.

Your call if it gets nasty, close it or moderate it, either way.

So please don't be surprised if the thread gets closed if it doesn't change course.

 

[Paul.M]

(Marvo posted at the same time as mine below.... good timing again lol)

So hi everyone, i have alot of electrical items in my room upstairs. And if anything were to fail i would like a switch that would turn everything in the house off.

Hi Dean and welcome to the forum. Why do you want the entire house to trip?

A lot of electrical items in a room upstairs in a house, are these sensitive equipment like computers/hi-fi system etc?? There are ways to provide local isolation and local RCD protection just for the room but you need to tell us what you are trying to protect and why you need an emergency button for a bedroom???

 

[Deleted member 72666]

I feel that we are not being given the full or even true information here as it doesn't stack up, "if anything were to fail" what do you mean by this, are you carrying out some sort of experiment? Is the room upstairs in question occupied by you or someone else?

 

[Pete999]

Okay, well how does an RCD trip in my consumer unit? What electrical fault occurs for it to trip? Like sometimes my irons break over time and trip it, how does it trip?

https://www.youtube.com/watch?v=mYapRr7ujzM

 

[Dean Longstaff]

I just have door access control system which isnt earthed. So if that were to catch fire i would like a emergency stop button to stop everything at once. Also my plug sockets ive installed throughout the home.