Chaps,
After reading several posts, threads etc about CU changes and what you are responsible for, i thought i would clear a few things up for those that are unsure.
Now, this affects anyone changing a CU to bring an installation up the current standard, which of course is BS7671 2008.
Now, the following are RECOMMENDATIONS and not set it stone, but its what i normally try and do, which can save a lot of time and trouble.
If you have been asked to price and change a CU, for whatever reason, you should ALWAYS carry out a site survey before any costs are discussed.
Now, once onsite consider carrying out the following:
1- Main Earth Bonding.
i) Is main earthing present?
ii) If so, is it adequate?
iii) IF not include this in your quote as this
MUST be up to current standards.
2 - Visual Inspection
i) How old does the installation look?
ii) Are there broken accessories?
iii) Is there evidence of any additions or alterations, good or bad?
iv) Ask the client of any known issues or problems in the past.
3 - Quick Basic Check & Tests
i) If convenient, isolate supply and take off the CU cover
ii) Evidence of additions or alterations?
iii) Carry out IR test between Earthing bar & Neutral bar at
250V
If everything looks ok then you are good to go, BUT, whatever happens, make sure you draw up some form of basic contract that highlights the fact that the quote does not include putting anything un-forseen right, and that if there are problems found during or after, then they may need to be rectified at additional cost.
Now, if there are issues with an installation that are not considered unsafe, although not to current BS, (unearthed lighting circuits excluded), you ARE NOT generally required to put these right, although they should be noted on the cert in the correct box.
4 - Certification.
There is a little confusion about what cert should be issued, of course, after a PIR is carried out.
The way i do it is, if i do a CU Change a full installation cert is issued, noting any deviations.
On the same cert any circuit additions or alterations can also be noted, so there is no need to write out multiples.
If you are just altering circuits with no CU change, then a separate minor works must be issued for each circuit altered.
Also, once you have changed a CU, carried out all the tests, you DO NOT become responsible for the entire installation - just the CU change.
This must be noted on the cert & periodic inspection label that MUST be fitted after the change with the words - "CU CHANGE ONLY".
Hope that helps, and if there any E&O's then let me know.
Good luck - As most CU changes need it
