- Joined
- Nov 28, 2009
- Messages
- 14,677
- Reaction score
- 832
From a recent Voltium post:
So now the RCD in a split load CU should match the rating of the service fuse, which up here is usually 100A
So looking for a small CU today, looking at Electricfix, not one appears to have a 100A rated RCD.
So are we all quietly ignoring this? Or does someone know a magic source of CU's with 100A RCD's?
Oh and now there is the need to pull the main fuse to actually see it's rating? Or do we assume 100A as even though it might not be now, the DNO could fit a 100A fuse at any time?
Regulation 536.4.202 – current rating of devices
The issue where there are split load consumer units with a 100A switch and an 80A or 63A RCD providing RCD protection for groups of circuits. Also, if you’ve got a 100A service fuse that doesn’t provide protection for your 63A RCD.
If you’ve a 100A service fuse that doesn’t provide protection for your 63A RCD. Previously, diversity took into account that if you’re the designer you could allow for your 63A not pulling any more than your 63A, and hence no need for protection. But the regulations say there is no diversity. Now, if you have a 100A service fuse or 80A your RCDs in split load boards should match the rating of those devices.
So now the RCD in a split load CU should match the rating of the service fuse, which up here is usually 100A
So looking for a small CU today, looking at Electricfix, not one appears to have a 100A rated RCD.
So are we all quietly ignoring this? Or does someone know a magic source of CU's with 100A RCD's?
Oh and now there is the need to pull the main fuse to actually see it's rating? Or do we assume 100A as even though it might not be now, the DNO could fit a 100A fuse at any time?