consumer unit tails

[krugger]

I'm looking at replacing the old fused type consumer unit with a new type. Is it is posible to break the seal on the board fuse to isolate the supply? If not how do electricians install new units? Is it possible to inform the board then remove the fuse your self?

 

[il78]

Usually sparks break the seals themselves and get the client to contact the electricity supplier to reseal, but sometimes they can get funny.....although your supplier should fit a double pole isolator between their meter and your board.......phone them and tell your situation, they usually do it for free.

 

[ashten]

You must not break the seals.

Contact your Electricty Board and they will send an engineer to reconnect the tails and test the board for you.

DO NOT Meddle with the Meter, Mains Fuses or Tails. You will normally need 16mm or 20mm Tails.

The Meter, and Mains Fuses are the property of the Electricity Board

 

[supersparks]

do we have another wanna be sparky here? or this just another form of mb?

16mm tails? thaught it was in the regs that its now 25.....where did 20mm come from? and ask the leccy company? you ever herd of anyone bothering?

 

[BR]

Perhaps this isn't appropriate for a diy website, but it is very possible to replace the CU without disconnecting the supply, provided you are careful. The 16mmsq meter lead could be removed, Temporally terminated (JB if you like) and clipped out of you way while you work. I of course cannot speak for the UK but in Ireland little attention would be paid to a missing seal on the service head (and the supply board will reseal it no problem if you ask them). Maybe the UK's are different but with the ones we have here it is possible to partially remove the main fuse and terminate the supply without breaking the seal on the cut out (not ideal but...)

 

[breezer]

as you said

Perhaps this isn't appropriate for a diy website,

some jobs are NOT for the diy person, in my opinion this is also one of them

 

[scooby]

I'm looking at replacing the old fused type consumer unit with a new type. Is it is posible to break the seal on the board fuse to isolate the supply? If not how do electricians install new units? Is it possible to inform the board then remove the fuse your self?

If you need the electric supplier can come and put a switch in between the meter and the consumer unit so you can switch on and off safely

 

[il78]

do we have another wanna be sparky here? or this just another form of mb?

16mm tails? thaught it was in the regs that its now 25.....where did 20mm come from? and ask the leccy company? you ever herd of anyone bothering?

Its still acceptable to use 16mm tails as long as the main fuse is 60A (cable is correctly rated) although when changing a board I would install 25mm any-hoos, also 6mm main earth and main equipotential bonding to gas and water when TN-S (as long as the Ze & PSC are within parameters) are still acceptable.......

 

[hsiboy]

also 6mm main earth and main equipotential bonding to gas and water when TN-S (as long as the Ze & PSC are within parameters) are still acceptable.......

WTF? when did you get your cards?

 

[il78]

Should of made myself a little bit clearer…….I should start reading my posts back rather than just submitting….

6.0mm is still “acceptable” when used on TN-S systems for main equipotential bonding to water & gas service pipe-work (although I would install 10.0mm). If you were to calculate this rather than “doing what I was taught” you could prove that 6.0mm would suffice. The range of external earth fault loop impedance (Ze) values, for allowing a main equipotential bonding conductor size of 6.0mm on a TN-S system is approximately 0.04ohms – 0.65ohms but you have to verify your own results….

The original post was made in haste…..and knowing that it would open a can a wriggle ones, I shouldn’t of bothered……but I like to know why, rather than “it just is”

 

[Handyman]

I have this problem, too, on my new house. I will probably just break the seals and do it. I lived in my prevoius house for 27 years, and the last time the local supply company came and looked was at least 12 years ago. How often do they check up? Never, I suspect.

 

[securespark]

As a pro spark I have done 100's of CU's, and in my area the leccy boards official line is call us out. But if you speak to the engineers themselves they say, break the seal and call us out later, leaving a completion cert at the meter.

At the end of the day, it is true no one will know who broke the seal (the boards used to keep tabs on the seal but not now) but never never work on it live.

It's not worth it.

I have seen what happens if you get a short at the intake (meter) position. The force of the explosion is enough to rip the gear off the wall.......