Adding RCD Unit.

SSE · Oct 24, 2012

Thoughts on this please. A new cooker circuit has been wired, the cable is already in the cupboard at the fuse board. The circuit will be terminated in an RCD unit fed with 16mm[SUP]2[/SUP] tails so that it has the correct protection. The tails from the main fuse are 16mm[SUP]2[/SUP] to the digital meter then 16mm[SUP]2[/SUP] to the fuse board. Are there regualtions on where the tails for the RCD unit have to be fed from? I've seen some come straight out the top of the fuse board switch before & some split from a connectorl block before the fuse board? Also would the main (from fuse-meter-fuse board) 16mm[SUP]2[/SUP] tails be enough or would they have to be changed to 25mm[SUP]2[/SUP]. There are quite a lot (about 8) circuits in the fuse board including a shower, two rings, 30A MCB to a shed so I'm wondering if the load is a bit on the large side with new RCD unit to be fed with16mm[SUP]2[/SUP]. The main fuse is 60A so obviously this will have to be changed to a larger fuse. Any help would be great. If there's an easier way to go about it I'd be open to suggestions.

DurhamSparky · Oct 24, 2012

but them in henly blocks!

RyanCheetham · Oct 24, 2012

Henley Blocks after the meter and before the CU and might as well put in an isolator at the same time

DurhamSparky · Oct 24, 2012

just by pass the meter..!! cheaper in long run

Engineer54 · Oct 24, 2012

SSE said:
Thoughts on this please. A new cooker circuit has been wired, the cable is already in the cupboard at the fuse board. The circuit will be terminated in an RCD unit fed with 16mm[SUP]2[/SUP] tails so that it has the correct protection. The tails from the main fuse are 16mm[SUP]2[/SUP] to the digital meter then 16mm[SUP]2[/SUP] to the fuse board. Are there regualtions on where the tails for the RCD unit have to be fed from? I've seen some come straight out the top of the fuse board switch before & some split from a connectorl block before the fuse board? Also would the main (from fuse-meter-fuse board) 16mm[SUP]2[/SUP] tails be enough or would they have to be changed to 25mm[SUP]2[/SUP]. There are quite a lot (about 8) circuits in the fuse board including a shower, two rings, 30A MCB to a shed so I'm wondering if the load is a bit on the large side with new RCD unit to be fed with16mm[SUP]2[/SUP]. The main fuse is 60A so obviously this will have to be changed to a larger fuse. Any help would be great. If there's an easier way to go about it I'd be open to suggestions.

What are you talking about, a single RCD unit for the new cooker circuit, or another CU that's RCD protected?? If it's a single RCD unit, i'm not understanding why you want to use 16mm tails, ...what correct protection are you talking about??

25mm tails are for 100A service supplies, the existing 16mm tails are pretty much good for up to 80A. You can only have 100A supply fuse if your Ze is low enough to accommodate it.

Why are you thinking that an upgrade of service fuse is required, have you clamped the incomer to check this massive load your envisioning??

SSE · Oct 24, 2012

DurhamSparky said:
but them in henly blocks!

Cheers.

RyanCheetham said:
Henley Blocks after the meter and before the CU and might as well put in an isolator at the same time

Cheers, no room for an isolator unfortunately.

DurhamSparky said:
just by pass the meter..!! cheaper in long run

Ha. If only!

Engineer54 said:
What are you talking about, a single RCD unit for the new cooker circuit, or another CU that's RCD protected?? If it's a single RCD unit, i'm not understanding why you want to use 16mm tails, ...what correct protection are you talking about??

25mm tails are for 100A service supplies, the existing 16mm tails are pretty much good for up to 80A. You can only have 100A supply fuse if your Ze is low enough to accommodate it.

Why are you thinking that an upgrade of service fuse is required, have you clamped the incomer to check this massive load your envisioning??

It's a single RCD unit for the new installed cooker circuit. I'm assuming 10mm tails for RCD unit will be adequate? My thoughts on an upgrade of fuse were because with the new circuit I think the current fuse won't be adequate, it's an awful lot of circuits (off the top of my head 4x 6A lights, 1x40A shower, 2x 32A rings 1x32A shed supply,1x 16A Water heater. Plus the new cooker circuit 40A max (although account to be taken for diversity). Unfortunately don't have a clamp meter to check the load. plus the new cooker circuits 40A max.

Engineer54 · Oct 24, 2012

Unfortunately don't have a clamp meter to check the load. plus the new cooker circuits 40A max.

That's unfortunate, because you'll would have then seen for yourself that you'll not be anywhere near that 60A you think you'll be exceeding!! lol!! Check out the other threads here on diversity and you'll understand why.

10mm tails will be fine for the single RCD unit your installing.

SSE · Oct 24, 2012

Engineer54 said:
That's unfortunate, because you'll would have then seen for yourself that you'll not be anywhere near that 60A you think you'll be exceeding!! lol!! Check out the other threads here on diversity and you'll understand why.

10mm tails will be fine for the single RCD unit your installing.

Think I might have to invest in one of these meters for future use then, lol. Perfect, I'll just use 10mm & split the current 16mm tails before the fuse board & split using blocks. Thanks.