commercial dsitribution board change leaving existing circuits non rcd protected

[hodgey1972]

I am changing a commercial distribution board like for like, Can someone confirm im correct?
Ive only allowed rcd (rcbo) protection for new circuits or circuits im working on, and noting in my installation cert, that those existing lighting circuits don't comply with amendment 3 regarding rcd protection.
Or where i should be looking in 7671 or to quote from
Thanks in advance.

 

[Pete999]

Would have thought that considering you are changing the complete Distribution board, including connecting your new circuits and the existing ones, the consideration should be given to protecting the existing circuits as well as the new ones.
After all you will be certifying the whole board and taking responsibility for the complete installation. Perhaps an EICR would nave been a better option, reporting your findings rather than just noting the omissions on the certificate. My opinion only.

 

[hodgey1972]

im trying to find in bs 7671 where this is stated.

 

[hodgey1972]

i will be testing the outgoing circuits to check disconnection times etc

 

[Andy78]

Any additions or alterations should comply with the current regulations.
You are changing the DB and altering the OCPD for each circuit and altering the characteristics of the circuit.
If the lighting circuits require 30mA RCD protection it should be provided.

 

[Darkwood]

This depends on the reason for a new distribution, if you are simply replacing like for like as you state but just a larger board then you effectively haven't changed any characteristics of the existing circuit and confirmation tests to their condition plus a note on the cert' would be all I would do. This is common if you wish to re-use all the existing OCPD's to save money when simply increasing the board size.

 

[Deleted member 26818]

To start with, any Certification issued should show the extent of the work.
Unless you particularly want to, there is nothing which makes you responsible for any part of the existing installation.
Secondly, there is nothing in BS7671 which refers to changing a circuit's characteristics, or suggesting that because of any such change, the circuit should be treated as being new.
As far as I am aware, there is no new requirement in Amendment 3 for lighting circuits to be provided with RCD protection?

 

[hodgey1972]

Rcd protection for buried cables in this case wall lights and switches

 

[hodgey1972]

Yes that's correct although the opd's are obsolete so 60898's replacing 3871's

 

[Deleted member 26818]

Rcd protection for buried cables in this case wall lights and switches

There is no new requirement for buried cables to be provided with RCD protection in Amendment 3.
In fact there is no requirement in BS7671 for buried cables to be provided with RCD protection, it is just one of a number of options available. However not an acceptable method fo rambles run beneath floors or above ceilings.

 

[hodgey1972]

Also if I'm correct is there anything in bs7671 or eawa I can use in my defence of my decision? I have a demanding client who I know thinks they will be able to try and push liability for the whole installation towards me, after reducing my quote for re-wiring to not include said circuits

 

[Deleted member 26818]

The EAWA requires that anyone who's work activities require experience, knowledge or sufficient supervision to safeguard against the dangers electricity may present, should be provided with such.
It is not your responsibility to ensure employes of the company you are carrying out the work for are suitably experienced, trained or supervised.
However there is now a requirement in BS7671 which requires RCD protection be installed unless there is a documented Risk Assessment indicating such RCD protection is not necessary.
It is the responsibility of your client to produce such a Risk Assessment.

 

[shanky887614]

Yes that's correct although the opd's are obsolete so 60898's replacing 3871's

by changing the ocpd from 3871 to 60898 you are changing the characteristics of the supply so you will need to makesure it complies to current regs

 

[Darkwood]

I would argue that in the case of a board change where the OCPD is changed then as long as you have not made the circuit any less safe then you can treat it still as an existing circuit wired to a previous edition of the regulations, I cannot see why changing a board should make you bring any circuit up to standards just because the OCPD has different characteristics, as long as the circuit isn't a code 1 for any reason then I would treat as existing.

This is my opinion not a regulation, I believe you have to ensure that any alteration or edition must comply to current regulations where this is in the form of altering or adding to the circuit then yes! your work should follow current regulation but where the alteration is not the circuit but the actual device protecting the circuit then as long as it doesn't afford any less protection for the circuit than the previous device it should be the case you don't have to bring the whole circuit up to regulations.

 

[Deleted member 26818]

If I recall correctly, it is only with MCBs 10A and below where Zs needs to be lower than that for re-wirables?