CU Change

[m4tty]

Hi,

Easy question for most on here probably but when you change a CU and have to do full testing on whole installation, do you become responsible for the existing circuits. What happens if the house owner has diy-ed spurs off spurs etc. Do you have to put right before you sign it off. Also if they wont pay to have the bonding upgraded (say its a bad/long run) can you put it as a departure or do you have to walk away?

Thanks

 

[spinlondon]

Before conducting the CU change, you should check whether the bonding and earthing are adequate.

If they are adequate but do not comply with BS7671, it should be noted on the EIC under comments on existing installation.

The only departures allowed, would be those that offer the same level of safety as would be achieved by compliance with BS7671.

The EIC should state the extent of the installtion that covered, and that would by what you are responsible for.

As for full testing on the whole installation, you are only required by BS7671 to I&T the work covered by the Certificate. Which in this case is the CU change.

Any defects in the existing installation, should where reasonably practicable be noted under comments on the existing installation.

Only defects or omissions in the work covered by the Certificate need to be rectified.

 

[ianmacd]

You sign the EIC and describe the works undertaken (CU chnage for example) and that is what you are responsible for. You have a duty to inform (and potentially fix) any unsafe conditions found. Surs off spurs off rings, just drop MCB size and treat it as a radial.

As for the bonding, yes walk away. Have a look at this link: http://elecsa.org.uk/downloads/public/Reconnecting%20Lighting%20Circuits%20with%20no%20Protective%20Conductor_ESC.pdf

 

[matt.leung]

you could always do a PIR certificate, on front page state that it is a CU change under discription of work or reason why PIR is being carried out... do a full schedule of tests and 25% or 50% visual....

 

[Lurch]

you could always do a PIR certificate, on front page state that it is a CU change under discription of work or reason why PIR is being carried out... do a full schedule of tests and 25% or 50% visual....

Pretty much what I've always done. Generally a CU change is part of the customer wanting to get the whole installation up to scratch for one reason or another so most of the other works tend to be done as well.

 

[steptoe]

changing a CU is modifying the complete installation, so you must test every circuit you have modified.

 

[spinlondon]

changing a CU is modifying the complete installation, so you must test every circuit you have modified.

Doesn't appear to be a Regulation to support this view in BS7671.

 

[batty]

Doesn't appear to be a Regulation to support this view in BS7671.

You are probably changing protective device so you need to ensure device will break circuit should a fault happen so loop test is minimum requirement but good idea to test insulation of circuit otherwise you may be back if faults are on circuit. The first is required by my part p provider and second is just commen sense.

 

[niceguy]

I always test the complete installation on a CU change, as this also alerts me to any nasty surprises.

No reason not to, especially as the CPD has been changed.

Its my name on the cert at the end of the day, and with that, i sleep very well at night.

Not at the moment though as i am missing my horse and im lonely. :|