This is my first time here, and I am impressed with replies, advice I have just read.
So please help me with a small problem.
I have wired in a new CU 17th edition with a split board and two RCD's.
I want to protect the freezer contents, especially when on holiday.
The problem is if the freezer radial circuit RCD, which has other circuits protected by it is tripped by some other fault, then the freezer will thaw.
So firstly, will a power cut trip an RCD?
So even if a power cut does not trip an RCD, I still think it sensible to connect the freezer radial wire to its own fuse ie MCB or RCBO and take the power ( feed ) from the main switch.
I can't make up my mind which would be better, but consider the following;
An MCB with feed taken directly from the main switch, may not work if the RCD is tripped, as the return would go through the DPDT RCD , effectively cutting off the return.
But maybe I could bypass the return bar, and take the freezer return direct to the main switch.
An RCBO with both the feed and return via the main switch would remain independant from the CU RCD's and providing power cuts don't trip the RCD element of it, then would maintain power to the freezer.
This is a bit of a puzzle to me, brought on by a builder I was chatting to, who insisted that with new CU with all circuits protected with two RCD's , it created this potential freezer problem.
I look to your learned selves for advice as the few people I have asked to date seem to develop a sort of glazed expression when asked before developing a slight twitch.