Is it safe touching the neutral wire of my design?

andrewmm

Joined Feb 25, 2011
1,173
Device, like hair dryer, does not come with a netural wire as it is enclosed inside a plastic case. Also, most devices made, may be for example from China , may not come with the netural wire.

So what would be the best ways to made available an on/off switch outside the house and prevent people from getting a shock?
You are i think mixing up neutral and earth

The volts in the system are generated between Live and neutral.
yes in a lot of countries, neutral is regularly bonded to earth, but that's not guaranteed.

Earth is there as a safety item,

Items that are double insulated, do not need to have earth , as there are at least two separate insulation barriers between the user and the live,
 

andrewmm

Joined Feb 25, 2011
1,173
I want a device to be switched on outside the house with a switch. The device is connected to the ac source without the netural wire, it is a 2 legs plug. So is it safe to just left the earth wire to be outside the house with the on/off switch ( the live wire is completely placed inside the house)?

Also, can a home circuit breaker protect against electrical shock of device connected without a netural wire?

Any advice?
>>>>
The first time I keep it remembered in the school, E-L-N, was some 30 years ago. I have mistakenly the two earth and neutral wires. So sorry about this.

I rewrite the original question above as follows:-

I want a device to be switched on outside the house with a switch. The device is connected to the ac source without the earth wire, it is a 2 legs plug. So is it safe to just leave the neutral wire to be outside the house with the on/off switch ( the live wire is completely placed inside the house)?

In case this plan does not work, what would be the best ways to switch on the in-house device?

Ok so a few things,
Depending upon the country ,there are very strict rules as to who can and can not wire equipment for outside use.

Getting it wrong can be very dangerous, Unlike inside, where you tend to be on carpets / an insulated floor, the ground outside makes a great conductor, ensuring lots of current through you ..

I'd always run an outside wire with an earth, probably use armoured cable,
thats the specifications in this country.

Even if the earth is not used at the far end, its there for a safety in case the wire is cut, or later you want to put an earthed device on it.
 
I think I know what's going on and it' way different. I think the TS want's a switch OUTSIDE the home that turns on something inside the home. The switch just has the HOT wire. In the US, it would contain Earth or ground.

The switch would get the ground wire to the case even if it it was run in plastic conduit. If it was burrend and cut by a metal shovel, the ground would act as protective ground and carry the fault current.

You should protect "that circuit" with a GFCI. It would likely be at the breaker with the feed.

So if someone touches the HOT wire before or after the switch and is standing on the ground, and there is a leakage path, the GFCI protection would activate.

AFCI or Arc Fault would try to protect against rodent damage. It detects the signature of arcing and turns off the circuit.

AFCI's and GFCI's are combined.

Weather proof switches are effectively double insulated.

https://www.grainger.com/product/4YF69 is a sealed switch, but it has a metal plate. If something degraded, generally the hot would short tot he metal. So you have a hot to earth short. Earth and neutral are connected together at one point, so fuse will blow.

If the gasket got compromised and a spider built a nest, then when it rains the nest would get wet causing a leakage patch and blow the GFCI.

The GFCI/AFCI adds another layer of protection.

A switch outside should be a sealed switch, have a ground. Connect at least to the switch ground terminal.

As the TS said, only hot and switched hot travel from outside to inside.

The US is moving or has moved into a situation where neutral should be provided to any box whetherit be a ceiling fixture or switch because it allows automation equipment that requires a neutral to be used IF NEEDED, In the US, we would call this 14/3 or 12/3 with ground with ground. You get a switch loop, ground and neutral.

Since we are protecting stupid people, the AFCI hopes to find a worn extension cord under a rug. The GFCI is a good thing and sometimes creates problems with motors.

Aside:
I had that hot to ground short one day. An outlet that I replaced not too long ago, moved to one side and the screw/wire touched the side of the box. Turns out the box was out of tolerance being 60+ years old, but I felt the outlet should not have allowed it. The elongated holes allowed the wires to touch the side of the box.
 
If I remember my NEC correctly, for residential new construction, GFI is required for A) Any outlet within 6 feet of a water outlet. This covers baths, laundry sinks and kitchens. B) Outlets within an enclosed garage are. For fuel fumes. C) Outdoor receptacles. To protect from water and protect extension cords. Also required is 3 wire circuit construction.
I havent read th NEC in a while. It is available to read only online, but I think AFCI/GFCI's are pretty much required everywheere.
AFCI's for bedrooms and living rooms primarily.

Tamper resistant outlets, again don;t know the requirement, in bedrooms primarily so kids don't stick stuff in the outlets.
And the neutral for automation devices.

House is wired primarily "power to the ceiling fixture".
 

MaxHeadRoom

Joined Jul 18, 2013
22,726
I suspect the OP is not a resident of N.A., The term "Earth" is usually used in U.K and elsewhere to indicate the N.A. ground conductor equivalent..
One would normally "Run an Earth wire" for example. ;)
Max.
 

DickCappels

Joined Aug 21, 2008
7,202
To get to the point, if you do not touch the Neutral (which carries load current, while Earth does not) you will be ok. Does that answer your question? If not, please explain your question again.
 
I suspect we have a language/interpretation problem too.

A lot of us here are from the US, so we don't know other country differences, but we may know of them. e.g. split phase, single phase, ring mains, mains voltages and frequencies around the world.
 

MaxHeadRoom

Joined Jul 18, 2013
22,726
Actually the aim is to achieve zero resistance difference between neutral and ground.
Where in fact there should be no more than a few ohms, when I entered the electrical field in the UK, at that time it had to be confirmed in an installation by measure resistance through ground, back to the earthed point, which was the star neutral conductor of the supply transformer.
Max.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
99
I wrote the post in order to get some feedback. Just after I posted it, I found that there was a flaw of it. If someone cut the outside wire using a metal scissor or just pull it out of the switch, it can be dangerous. The outside is somewhere I do not have control of. That may be safe if it is only used by myself.

Perhaps I should get some dc source low voltage switch instead.
 
In the US, we something called CAT 2 wiring. This is typically <100W, power limited and <24V like doorbells. No conduit is required. There are what;s called "energy limiting" transformers, usually 40VA @ 24 VAC used for furnaces. They will withstand a short with no fusing.

That can work for you,
 

DickCappels

Joined Aug 21, 2008
7,202
The current term in transformers I have been encountering is "impedance limited". I asked my client to get be a couple of transformers for evaluation. He had enough sent to me for a small production run. Sadly when I test them they turned out to be impedance limited, being terribly poorly regulated. I still have them under one desk or another :-(
 

MaxHeadRoom

Joined Jul 18, 2013
22,726
This is sometimes used to advantage as in the characteristics of the SMAW arc welder transformers, with these, the operator can vary the secondary coupling in order for the arc voltage to collapse as soon as the arc is struck!
Max.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
99
I have the idea of a modified design.
Now all the previous parts are moved inside the house.
A string going through a hole is attached to the switch. Pulling the string will turn on the device like flushing the toilet bowl.
(Turning off the device is done inside the house)

So, I need to find a type of such switch.
 

dendad

Joined Feb 20, 2016
3,796
Here in Australia, only qualified electricians are allowed to install mains wiring.
I think a good rule of thumb is, "If you have to ask advice or are unsure of mains wiring, do not do it!".
You may be ok with it and know what you have done, but the next person on the scene will assume it is wired correctly and you may be responsible for electrocuting them.
I echo the sentiments of many above, do it right, or not at all.
 

Thread Starter

Leon_Chan

Joined Sep 11, 2019
99
View attachment 228535
Plus
View attachment 228537
But just what are you trying to do? How about at least showing us a sketch? I am not sure, from what you have said, that you know how to do whatever it is that you want to do safely...
It can be any equipment with a plug, for example a desktop lamp, you will turn on inside the home. The requirement is just to turn on it outside the house safely.
You may also add another string to turn it off but it is not required in my case.
The switch can also be a magnetic one so that the string pull away a magnet that close the circuit immediately. Putting the magnet back will turn that off again.
 

Wolframore

Joined Jan 21, 2019
2,246
please check your codes/electrician. The responsibility lies on you, if you’re not an electrician making changes to your wiring. Also I do not claim to be an electrician and do not offer any advice.

for the sake of conversation,
AC system needs to be grounded. You should not switch the neutral because it will leave the device hot, check your codes, it is the HOT that is switched. Your neutral should not be disabled by a switch.
The hot can be safely switched from an outside location

1. All conduit and enclosure should be properly grounded separate ground wire.
2. All outdoor circuits should be protected by GFCI
3. A weatherproof enclosure used for outdoor

again not an electrician you should check with one that's licensed and bonded.
 
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