Refurb works In offices

Just your thoughts on this one,doing a part refurb on existing offices,no initial verification or certs found anywhere.
Premises rewired bout 1990,adding sockets here & there in each room.
The DB is a Crabtree Tpn polestar,just finished some loop readings ,& not good,1.49 the highest,there is no rcd protection on any of the circuits,the ring mains are of a 3871 type 2 32 amp.
We are now waiting from architect or whoever on what to do.
In the meantime bit concerned about our new additions,should I refuse to connect them up.

 

all depends on what you are fitting. if RCD is required under various 7671 regs. then you need to provide same. all you need to do is ensure your new works comply and sod anything else ( unless you perceive a danger, then it should be addressed).

 

This is where the "description of work" on the EIC will CYA.

Be descriptive, and detail your work.

In the comments section, raise any issues.

Then its documented........

 

My thoughts on doing one assess what's on the existing circuits in works area and is the circuits wired to a good standard to be adapted/strip out back to a point to start afresh as much as possible .
Zs of 1.49 you have to ask why what is the Zs/Zdb ?.

 

If you have carried out alterations and additions to existing circuits you should have verified the suitability for the work you are carrying out before starting. It's no good refusing to connect after you've altered the circuit.

 

If you are adding to existing circuits then circuit protection must be adequate.

 

Agree,I’m not going to connect until someone tells me I can,the loop reading do not comply,there is no rcd,& doubt if you can retrofit a rcd to that DB.
This installation been in service like this quite some time,nobody’s said,or done anything about this problem

 

Who designed the alterations ?

 

Is the Zs correct for the circuit layout, e.g. long ring final or radial but with incorrect circuit protection.

 

Yea everything fine,regarding the new circuit,all dead tests are fine,the Zs are the problem,through out the this area,on ring main.

 

The alterations are not the problem,they consist of extra power points to the existing ring,that ring causes the problem.

 

Is the Zdb low for what it is ?. If so investigation/improvements would need to be done on the existing and what about RCD protection ?.

 

Yea the Tpn Zs is ok,it’s the existing high loops,it’s basically adding a couple of power points in the office.

 

I think my point was that the design of the alterations should have taken into account the values associated with the existing circuits and their suitability for the alterations.

 

It is usually in the spec that investigation prior to works should be sort by the electrical contractor should take place.