Discuss 18th Edition Compliant Consumer Unit in the UK Electrical Forum area at ElectriciansForums.net
No however Jpel/64 or Beama who are on the panels aren’t they are tell us yes?Are you telling me that say 3X 32A breakers plus a few 6A for ligting are going to exceed the 100A mains switch not to mention the absolute max of a 100A BS1361 type 2 incoming fuse ?
Historically we have used diversity of the final circuits to ensure that the rccb is not overloaded.
Now it seems we can not rely solely upon diversity of the final circuits downstream of the rccb and overload protection must be ensured by other means like having the upfront ocpd rated lower or equal to the rccb and main switch or ensure that the final circuits added are not greater than the rccb and ensuing manufacturers instructions are complied with.
I know with Hager they have taken the approach of fitting 2x 100amp rccb’s (Also now type A) in their dual rcd consumer units so obviously they intend to ensure that their rccb’s are not overloaded and have defaulted to use 100amp devices.
This is certainly the guidance also given by my companies scheme provider.
The key sentence is that we can’t rely solely upon diversity of the final circuits and that manufacturers instructions are followed.
Given that Hager have jumped in and defaulted to using 100amp devices , my interpretation is that we must ensure the rccb is protected by not relying on the diversity factor
Are you telling me that say 3X 32A breakers plus a few 6A for ligting are going to exceed the 100A mains switch not to mention the absolute max of a 100A BS1361 type 2 incoming fuse ?
Oh I don't disagree, a full RCBO board is always nice to have if the customer will go for it, however they should always have been DP, or at least SPSN from the get go for obvious reasons.
because if you get a N-E fault this will of course trip the up front SP RCBO device, however by being SP will leave the N-E fault still present.Why? Where does it state they should be ? When we don’t fit DP or SPSN Mcbs
because if you get a N-E fault this will of course trip the up front SP RCBO device, however by being SP will leave the N-E fault still present.
Now if this was a farm or agricultural install this will also trip the front 300mA RCD required for fire protection, with no means of being to isolate the fault, at least a (SPSN) single pole switched Neutral would Isolate the N-E fault.
This should have been designed in from the get go, even for domestic where a SP RCBO still would leave a N-E fault present.
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