Replaced a garage consumer unit in my SILs shed last weekend.
Easy enough because we could kill the breaker in the house.
But I wondered, how is it done if you change the CU in a house?
There isn't an outside 'stopcock' for electricity.
Is it done 'live'?
Isn't there a main breaker you turn off?
It's not uncommon to have a two-pole isolator between the meter and the CU.
No, if there's no isolator, the main fuse in the cut-out before the meter would be pulled (officially or otherwise) at that point it's a good idea to fit an isolator.
You pull the main fuse on the riser.
5 ways:
1) Pull the cutout fuse;
2) Disconnect CU tails from henley block if you have one;3) Work live;
4) Operate main isolator if fitted;5) Operate meter's built in isolator if the right type.
1 - EDF charged me 35 squid to pull and refit the fuse - they took all day to come back. This would be the most painful way, but arguable the "correct" way in the absence of other options. My seals were newish.If the seals are broken or are not new looking, they might "fall off" allowing you to pull the fuse. HOWEVER be warned that old and flaky cutouts fed by paper insulated cable dating to 1940 show never be touched as a) The cutout may break up in your hands or b) the cutout comes off the wall, bends the now brittle and dried out cable and it dumps a short circuits worth of metal plasma in your face.
2) Technical working live, but with the right tools, good access and done carefully is not particularly dangerous. I have done this. I do not recommend anyone else does.3) The most dangerous option - so much as to be a non option for anyone who is sensible. It is probably done sometimes. But there is no need.
4) Some supply companies do fit these. I fitted my own. EDF were not hugely keen but they put up with it anyway.5) Do check - certain makes/models of meter do have an isolator built in
- some Siemens types.
You still have to cut the seals on the meter to access the isolatior switch.
But isn't 2 "working live" as the henley block terminals are live? Admitedly you then have dead tails to work with rather than live bare ended live ones waving about.
Incomer, risers are water. B-)
Most installations have that as part of the CU that is being changed...
No one has mentioned the pole fuse outside. Ours was only about 8' off the ground until they came round replaced it, the stays and capping over the earth bonding etc. It's now about 16' above the ground. It only feeds us so pulling that wouldn't cut anybody else off.
Really? Seems stupid... And somewhat pointless. Undoing 2 screws live to remove the CU tails is not hugely risky.
I also read somewhere that the new smart meters will not have isolators either...
Or a cut out.
I have heard the term dry riser used for electrical supplies in flats. It's not a name I would use.
Yes - I was going to footnote that but forgot.
You said exactly what I was going to.
Live working on something fixed does not bother me. Having a live bare ended wire flapping around does.
En el artículo , ARW escribió:
I thought the term 'dry riser' referred to a hollow vertical shaft in multiple-storey buildings used to carry services such as gas, water, power, drainage, telecomms, etc.
That is where I have head the term used. However the water supplies would be in a wet riser (IMHO) and things get more complicated in high rise flats where there are dry riser pipes intended for use by fire fighters.
Just screw them into spare henley blocks or the isolator you are going to fit.
Here there seems to be a main fuse, a Seeboard timing device, meter, about 4 CUs and another switch or two, one of which is labelled "main breaker" but probably isn't.
Well they contain a contactor that can disconnect the supply. Even if they offered a facility for you to call them and arrange a temporary disconnection, would you trust it not to reconnect when you least expected it?
"ARW" wrote in news:lrl4ij$988$ snipped-for-privacy@dont-email.me:
Dry Riser is used by the fire service in the event of fires in the building. As it is kept dry it cannot freeze.
We'll get on to pattress in a minute. ;-)
Ther is. At the local substation
Often, yes
>HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.