Consumer Confusion

[Power Ball]

I am looking to install a new CU to replace an old wylex but noticed while I was shopping around you can buy either Dual load ie 1 main switch 1 RCD on a 10 way or 17th Split way with 2 RCd so every thing covered ie 6x4 5x5 or 4x6

I thought everything had to be coverd by RCD so does that mean on the first unit 1 RCD has to cover all 10 mcb's

Why do they still sell the Dual unit with 1 RCD ??

Thanks

Chas

 

[binky]

the first option is a 16th edition compliant split load CU. You should be fitting the dual RCD CU

 

[batty]

the first option is a 16th edition compliant split load CU. You should be fitting the dual RCD CU

Or you could fit a 16th edition board and use Rcbo's on some circuits especially Cooker and Immersion circuits that way you won't get nuisance tripping.

Batty

 

[Andy™]

a DB with an RCD feeding more than one circuit doesnt fully comply with 17th ed. it never complied with 16th either. more a cost/inconvenience thing as to why its so widely used. split load was used for 16th, but with 17th wanting everything on RCD, dual splits became more popular (they were often used for TT under 16th ed)

anyway, not everything has to be RCD'd, which is why there are many different types

 

[Power Ball]

Thanks guys

I normally fit the 17th split load ones but just wondered why they still sell the old 16th ones and now I know.

Thanks

Chas

 

[Andy™]

you can load up the non-RCD side with non-RCD circuits or use RCBO's

 

[batty]

There is nothing to say you have got to use a 17th edition board. I generally fit Rcbo's on main switch boards. The new house I am doing at present has all Rcbo's apart from cooker circuit which is installed in galv conduit in walls and garage circuit which is in galv conduit in walls in house and Rcd board in garage. May take a little longer to do first fix but at least I won't get callbacks. Only problem with using Rcbo's, boards can get a bit overfilled as they are not really designed to take them. I may try the moeller boards because they seem to be designed better for taking Rcbo's.

Batty

 

[green-hornet]

a DB with an RCD feeding more than one circuit doesnt fully comply with 17th ed. it never complied with 16th either. more a cost/inconvenience thing as to why its so widely used. split load was used for 16th, but with 17th wanting everything on RCD, dual splits became more popular (they were often used for TT under 16th ed)anyway, not everything has to be RCD'd, which is why there are many different types

This is actually a very good point and worth remembering.

The layout of all domestic consumer units have never applied with the regulations, be it 16th or now 17th.

This just shows how governing bodies can bend the regulations to suit consumer choice.

If you take a 17th dual rcd board with say 12 ways that means that for each rcd 6 circuits will trip, this would be an inconveniance to me never mind anyone else.

Rcbo.s are too expensive an option for most so we have to comply with the bending regulations as best we can.