Can you run a sub RCD unit of a main RCD unit?

ey143

Firstly, I will get advice from a professional electrician, I am just asking here to get others views especially those who are qualified electricians.

I have just purchased a new large detached house, a part of which has its own granny annex side extension and own self contained unit with its own front door. I plan to rent this side out.

However, the whole house is in need of total rewiring and I am considering my options in terms of how I might want to propose this (eventually) to an electrician.

Rather than putting the whole house including the granny annex on one RCD unit, is there a way to have the granny annex on its own consumer unit (and kept within the granny annex too) and this unit feeds of my main consumer unit?

What I am trying to avoid, is a situation where I am on holiday and an RCD trips and nobody is in the main part of the house to switch it on again for the tenants. I'm trying to avoid having two separate electric meters (yes meters) in the property (which it currently does for the different parts of the house). A day will come when I will want the whole house complete without renting out the annex so would want to keep the meters / RCD units simple.

Ultimate question is, can you have a sub RCD unit work of a main RCD unit and if so, if the sub unit trips, will it also trip the main/master RCD unit?

Thanks.

longtimelurkersam

I guess this is similar to what I have in my garage/workshop, I have a main RCD in the flat and then a sub RCD in the garage, however I don't think this will solve your issue as if the main property trips then the sub RCD is fed from this.

Unless of course what you are thinking it running it straight from the meter, in which case I have no idea and one of the bright sparks will be along in a moment I am sure to guide you further......

ey143

What if the sub RCD unit is run off the main consumer unit's non RCD section?

Quiet_Spark

ey143 wrote: »

Rather than putting the whole house including the granny annex on one RCD unit, is there a way to have the granny annex on its own consumer unit (and kept within the granny annex too) and this unit feeds of my main consumer unit?

You could have it wired that way if you like, or for true independence you can have two individual consumer units both fed from the meter.

Your electrician will advise further once he or she has seen the job.

ey143

Hi quiet spark,

Could you pls expand a little on your suggestion of running two consumer units off one meter. Never seen this before - is this ever done? What are the downsides to this.

If there are two meters in the house, I suppose it would be more costly to run because of daily standing charge etc right?

Is there an easier way of apportioning cost and measuring use of electricity used in an annex without two main meters?

Thanks.

Electrician_Surrey

There are no downsides, you have the new consumer unit local to the annex, so if anything tripped out your not having to go next door. you can get a 2nd meter for the annex to see power usage.

ey143

Thx. Are there any specific websites or 2nd meters that you can recommend or point me to?

Electrician_Surrey

Just type in 'check meter'

Give a local electrician a call they can advise you more, electricity kills :eek:

keystone

Ho will your tenants a) be charged for and b) pay for their leccy if you don't keep the second meter?

Cheers

Myser

Split your electricity supply after your meter with a Henley block:

http://www.tlc-direct.co.uk/Products/MK1100.html

Sub-meter with something like this:

http://www.tlc-direct.co.uk/Products/RDCRED100.html

Install a small consumer unit after the sub-meter for the flat electric supply. This will also contain its own RCD(s).

Avoriaz

ey143 wrote: »

..I have just purchased a new large detached house......However, the whole house is in need of total rewiring.......

Complain to the builders.

A new house should not need rewiring.

:whistle: