Regulations stating CU must be upgraded (or not)

[ringer]

College lecturer told us that if any work is done an an installation with e.g. rewireables or 16th Ed board , then the CU must be upgraded. This in not what I have come to understand, but trawling through the BRB I cannot find specific regulations to confirm or deny this. I thought you can leave the old CU as is, as long as it complied with the regs at the time it was installed and you do not leave it less safe than it was before you started working on it. E.g. job with rewireable CU needs new shower circuit - leave rewireable CU as is, but add a separate CU with a RCD for the shower. Another e.g. would be adding a light in the loft to existing upstairs light circuit (non RCD protected) in a 16th Ed board - not sure here what you can/cannot do. Of course you should always suggest to customer to upgrade the CU, but in the real world they would not want to fork out the extra cash. Can anyone quote me regulation numbers that apply?

 

[Johno]

Generally when a rewire is needed so is a CU uprade (I have never came across anything other).

As for additions, etc, it is for YOU to make sure that the work you do complies with current regs, eg, if you are installing a new shower circuit then you could install a separate RCD to protect your circuit, but would it be more value for money (for the customer) to get the board changed at the same time.

I would try and explain this in very simple terms, and give them 2 prices= 1 with minimum work required and 2= the full monty.


As for the light in the loft, as long as the cable is surface mounted then there is no need RCD protect.

 

[Sparky Ninja]

Saying that there are regulations dictating that CU's must be upgraded is just incompetence on behalf of your tutor. I would never tell my guys rubbish like that.

I went through earthing & bonding with them tonight and this subject kept coming up. The conclusion is that there are always options to be considered, however, changing of a consumer does result as a more affordable approach to making a lot of existing installations comply, in comparison to all the other minor works that may be needed.

 

[Sintra]

College lecturer told us that if any work is done an an installation with e.g. rewireables or 16th Ed board , then the CU must be upgraded. This in not what I have come to understand, but trawling through the BRB I cannot find specific regulations to confirm or deny this. I thought you can leave the old CU as is, as long as it complied with the regs at the time it was installed and you do not leave it less safe than it was before you started working on it. E.g. job with rewireable CU needs new shower circuit - leave rewireable CU as is, but add a separate CU with a RCD for the shower. Another e.g. would be adding a light in the loft to existing upstairs light circuit (non RCD protected) in a 16th Ed board - not sure here what you can/cannot do. Of course you should always suggest to customer to upgrade the CU, but in the real world they would not want to fork out the extra cash. Can anyone quote me regulation numbers that apply?

There is no regulation as BS 3036 is still an acceptable form of overcurrent protection in the brb.

Any addition or alteration though has to comply to the current version with regards to additional protection if required. The example you gave for the shower is fine and as for the light in the loft you can install an RCD protected FCU for buried cables or if cables are surface or in mechanical protection then the circuit can be extended and the BS 3036 left as the overcurrent protection. Provided you are below the max permissible Zs.

 

[Des 56]

The lecturer,if you have not mis quoted his opinions is mis guided to say the least

You could install on your next rewire an installation that was made up of rewireable fuses and rcds

There is no reason to replace rewireable fuseboards just because they are old hat

With any board and the protection that is used, it has to meet the values prescribed,and the make up of the unit should allow for discrimination

If you decide that fuses are your choice, then there is nothing other than compliance to stop that choice


It is a very unsatisfactory state of affairs we have,when our people in our industry are making the customers fearfull of things that are not "the now",they may very well be safe, and sometimes even comply with the modern standard

 

[Sintra]

Have to agree Des too much bad guidance going on by both sparks and lecturers.

 

[Phil]

the trouble is in some colleges the tutors not all but some have not done anything in the trade for a few years so they can get a little left behind. i have seen both good and bad in the classrooms and some that talk absolute nonsense. we were told at college by one of the tutors it would be acceptable to spur of a spur and then again if we wanted too. ? and no he didn`t mean with an fcu in between either. another one told us running cables in any circumstance horizontally was illegal?

 

[Johno]

Has anyone ever done a rewire (domestic) and not changed the board?

 

[Phil]

never, always a board change for me if there is a complete re-wire

 

[Johno]

BTW am not defending the idiots that teach us the regs at college, am talking real life.

 

[Deleted member 9648]

How many times do we hear someone say..."I was told my fuseboard is illegal".....?

 

[jpmiff]

If the Zs values of the circuit meet the requirements in the BRB for the appropiate cicuit protection device then there is no problem!

 

[Risteard]

Don't forget derating factor of 0.725 for BS 3036 rewireable fuses.

 

[Spudnik]

How many times do we hear someone say..."I was told my fuseboard is illegal".....?

Believe it or not, had one yesterday.

Going to see the client tonight.

 

[nickblake]

the only time i will change a rewirable board ,is when it has the little wooden frame attached to the bakalite front ,as i feel this is a deviation ,due to the fact that if a fault developes within the board they could catch fire ,and these old board or of course if a board is faulty , defective main switch ,poor condition , etc ,, but i do have to admit i hate the things ,and will replace one if asked at a drop of a hat