I think this has been covered once before, but one of the current IET publications shows on the schedule of test results Max Zs as 1666 when protected by RCD (possibly RCBO as well) even when having a TN-C-S connection. I wondered what was the current opinion on this.
Current model forms have a column for max Zs and the publication is the current edition of the electricians guide to the building regulations.
Squinting at BS7671 and GN3 forms again and yes, I missed the new box for max permitted Zs. However, in pages 126 and 127 of GN3 the "filled in " sample forms have that figure as per the circuit breaker not as the RCD. Same in Onsite Guide.
Do not have the latest building regs publication you refer to, so cannot comment.
Current model forms have a column for max Zs and the publication is the current edition of the electricians guide to the building regulations.
Squinting at BS7671 and GN3 forms again and yes, I missed the new box for max permitted Zs. However, in pages 126 and 127 of GN3 the "filled in " sample forms have that figure as per the circuit breaker not as the RCD. Same in Onsite Guide.
Do not have the latest building regs publication you refer to, so cannot comment.
