Dual Tarrif Consumer Unit Question

[porcupine]

We have bought a house which has a 2/3 year old ‘new’ GE consumer unit.

It has either an 80A or a 100A DP main switch protecting the off-peak supplies, which are 3 x1.7KW storage heaters and 2 x.85 storage heaters plus an off peak immersor for a hot water cylinder and all 5 are all on individual 16A MCB’s. (The 2 x.85 are covered by one 16AMCB.) 5 in total on the off-peak supply

The normal full rate supply comes into an 80A 30M DP RCCB. This protects the two ring mains, each on 32 amp MCB’s, cooker on 32 MCB, lighting on 6MCB, full rate immersor on 16MCB and an electric shower on a 40amp MCB.

Should the normal rate supply be split in the CU and be protected by a DP Mains switch or is it OK for all the normal rate supply to be directly protected by the RCCB. Everything works OK but after reading some of the posts on other subjects it seems that lighting circuits might be better outwith a RCCB to avoid the house in darkness if any earth fault occurred.

What comments please??

 

[plugwash]

its not ideal to have everything on one RCD but CUs that can take a three way split are rare and expensive (mks largest one can)

the usual way would be two have two seperate CUs but many would consider this untidy

btw that CU should really have a warning on it if it doesn't already to say that there are multiple incomers.

 

[porcupine]

Thanks Plugwash for the reply. Perhaps we should look at having two seperate CU's with the circuits needing RCCD additional protection in the other. A notice is NOT on the unit but will be NOW!!

 

[porcupine]

Whoops I meant one Cu for the off peak and the other for 24 hour supply part of which is split into RCCD protection for Shower and Ring Mains, and the rest, Lighting, Cooker ,Immersor o outwith the RCCD protection. Does this sound much more the norm??