How far down does the safezone go from the top of the ceiling ?
Drilled into electric cable
- Thread starter lovelyhead
- Start date
Sponsored Links
150mm.
- Joined
- 11 Jan 2004
- Messages
- 42,818
- Reaction score
- 2,652
- Country
But if there's an accessory (or Consumer Unit) underneath the cable run, the safe zone extends down to the accessory and extends to the width of it.
Not sure that a 5A fuse would offer very much protection either. Only an RCD would be helpful.
Sponsored Links
I know that. I was just trying to drive home the danger to the OP.
Fair enough.
This is why I suggested he reads up on safe zones, since where he drilled is likely to be in 3 of them! 150 from a corner, 150 from a ceiling and directly above the CU (an assumption which is why I asked for a photo from further back)
My goodness, you are probably right and that is even more terrifying than the drilled hole. The person who cut that is very lucky to be alive and not to have some very nasty burns.
Whilst the cables appear to be in a safe zone (a wider photo would be good to determine that), would you ever run a concealed cable before a domestic CU without setting it at least 50mm back or mechanically protecting it? Just a general question for the domestic electricians on here. As mentioned most people do not understand safe zones, or even give any thought to how switches and sockets get their power. The number of shelves on living room walls around the country with brackets directly above sockets or in the corners of rooms, and pretty much any DIY kitchen with wall units is testament to that.
Its interesting.
I was trying to work out where my tails go last week.
CU in a garage thats now been converted to a room (and not very well).
Looks like my tails go up 10 inches (26cm) to the side of the CU.
Not sure how they get from there, to the other side of the closet where the meter is. Would they be in the roof space? or around a door frame?
I was trying to work out where my tails go last week.
CU in a garage thats now been converted to a room (and not very well).
Looks like my tails go up 10 inches (26cm) to the side of the CU.
Not sure how they get from there, to the other side of the closet where the meter is. Would they be in the roof space? or around a door frame?
A severe electric shock requires two points of contact with the body to enable significant current to flow through the person. So unless they were touching something earthed or neutral when they cut into the cable they would only get a mild "shock" ( a tingle ) due to capacitive coupling of body to earth.
Do NOT try that as a damp wall can provide an earth sufficient to allow muscle jerking current to flow Most electrical accidents are due to muscle jerks causing people to fall off ladders.
All the cables here run above a door from the consumer unit. Of course the same thing happened here, not by me, but he managed to short out live and earth and it blew the main 100amp fuse. DNO were not too impressed.
You can never rely on save zones, always use a detector if you are not sure.
I don't understand how this person didn't get a massive shock, I can only assume it was because the blade of the knife some how only touched the insulation and not the copper.
You can never rely on save zones, always use a detector if you are not sure.
I don't understand how this person didn't get a massive shock, I can only assume it was because the blade of the knife some how only touched the insulation and not the copper.
They'd be much better renamed "unsafe zones".
The severity of a shock off the mains depends mainly on the current path through the body and how good the return path is. If there is no return path then at least in theory you shouldn't get a serious shock*. The current rating of the circuit is pretty much irrelevent**.
* In practice I wouldn't want to rely on it outside of VERY carefully controlled conditions. The risk of their being a return path you didn't account for is too high.
** Yes a lighting circuit is likely to have a higher source impedance than the meter tails but it will still most likely be < 1 ohm which is negligable compared to the resistance of the body.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
