Thoughts please

[sdc8843]

Hi Guys,

I have just started with a new company and want to run a couple of things by you all.

1. They only want Minor Works Certs filled out for changing lights in bathrooms and sockets in kitchens. I thought it was work on any circuit in kitchen and bathroom because they are special locations.

2. On a certificate in the box Maximum Zs permitted by BS7671 they want me to record 1667 ohms for any circuit controlled by a RCD rather than the tabulated value in the regs.

What are your thoughts

 

[Des 56]

Sounds a reasonable request

What has a special location got to do with certification ?

 

[deafboy]

For changing lights sockets etc in special lcation a minor works is fine as long as there is no changes to wiring.
The RCD is an interesting one i would they could possibly be right however i personnally use the tabulated values (@100%) with regards to the overcurrent device.
At the end of the day its down to whoever signs as the Inspection and Testing to decide what values they put.

 

[Sintra]

Hi Guys,

2. On a certificate in the box Maximum Zs permitted by BS7671 they want me to record 1667 ohms for any circuit controlled by a RCD rather than the tabulated value in the regs.

What are your thoughts

This is a tabulated value in the regs. Table 41.5 p 50

 

[Des 56]

The correct value is the tabulated value agreed
The fgure of 1667 is for an rcd on a TN system

With a TT system.the earth loop impedance is usually pretty high ,therefore the fault current used to operate the RCd will be low and it dis connects as it should
On a TNC-s system the fault current will be very large and could cause a high enough volt drop that may cause non functioning of the electronics of the RCd, and it may not operate,so cant be relied on for fault protection

Having said that,the person oversigning the certificate takes that responsibility,so just go with his method, then keep in mind why I detest the shortcomings of the Qualified supervisor system nonesense operated by that most electricial industry un friendly creatures the Niceic