Consumer Unit RCDs

[AdamCH]

Thanks Steve,

Not easy to run a separate feed to the fridge so guess I'd have to try it on a RCD & see if there was a problem.

There is a socket on the cooker unit but there's an unoccupied double socket next to it so no problem changing the cooker to a no socket type.

Burglar alarm can be on it's own circuit & left of an RCD.

How strongly wold you feel about not putting lighting on an RCD? Upstairs & downstairs could be two separate RCBOs.

I suspect that the main problem I'm going to have is that there isn't a lot of room where the existing consumer unit is - squeezed above the meter board. It'll be a minor miracle if the cables have enough slack in them to reach a repositioned consumer unit.

I'm assuming that it's not straightforward to have the meter moved down 6 inches?

Adam

 

[Steve]

Think about this scenario.

You have guests round, you're all tipsy. Had a few to drink. One of them has just been to the toilet, and is at the top of the stairs coming down. Lights go out. What happens next? Leave it to your own imagination. But this is the reason lights dont go on RCDs.

 

[Steve]

When the meter is replaced, you could ask the meter man to move it down a bit if theres slack on the cables, but you could be waiting 20 years for this

 

[RF Lighting]

How strongly wold you feel about not putting lighting on an RCD? Upstairs & downstairs could be two separate RCBOs.

Unless you use MEM RCBO pods, then just try and find a 6A type B RCBO

Good luck.

 

[AdamCH]

How strongly wold you feel about not putting lighting on an RCD? Upstairs & downstairs could be two separate RCBOs.

Unless you use MEM RCBO pods, then just try and find a 6A type B RCBO

Good luck.

Ah Yes hadn't thought about that!

Many thanks for all the advice from everybody.

cheers

 

[plugwash]

a C6 will almost certainly be fine for a domestic lighting circuit unless the external loop impedance is out of spec or the circuit is insanely long.

 

[Anteaus]

Alarm is SELV so preferably shoud be non-RCD. Though, either will do so long as the backup battery is good.

I used one of these Wylex units earlier this year, and generally they're OK, one point I don't like is that (with the front removed) the busbars are only covered by a flimsy plastic strip which is easily knocked-off. This means you need to be a bit careful if working with the power on. The MK Sentry are better designed, but more costly. You pays your money...

The MCB slots and neutral bar are both split 50/50 and you need to use the correct side, if you connect a circuit to an RCD way then the neutral must do likewise.

 

[AdamCH]

a C6 will almost certainly be fine for a domestic lighting circuit unless the external loop impedance is out of spec or the circuit is insanely long.

Ok I'm confused now.

I can see Type B & C MCBs but I can't see a type against the RCBOs.

The Wylex RCBOs only seem to come in 16amp & upwards so would rule them out for lighting.

Btw What's the difference between Type B&C MCBs?

 

[Spark123]

The magnettic setting on a type B MCB is different to the magnettic setting on a type C. A type C is more tollerant to the current surge caused by start up current from some items. As a higher current is required to trip the magnettic part of the MCB the maximum permitted earth fault loop impedance is lower for a type C.

 

[securespark]

There is no need to RCD protect all your circuits.

But yes it is best to use RCBOs on the circuits which do require protection. (but cost often prohibits this)

Is your name JohnD on your days off??