paul777 wrote: ↑Mon Apr 24, 2023 12:29 am
my question is can I run a 6mm cable and install a 40MCB at circuit board ?
Answer is dependent on your skill and were you live and if you mind breaking the law, or are prepared to pay silly sums to the LABC.
New circuits in England and Wales need notifying, and in Wales kitchens are special locations, personally unless a rental property I would not worry, how will they find out? But the question is "Can I".
To upgrade a home every time the regulations change is not required, but any new work must comply to current regulations, as to if you can use the RCD as type AC not type A is a matter for debate, and I would not worry about it, however an inspector could require it to be changed. Since a new circuit should be protected with a type A.
A B40 MCB to work on the magnetic side needs 5 x 40 amp to flow, plus 5% for safety, so the loop impedance needs to be better than 1.1 Ω and the meters to measure that are expensive, so step one is get out the EICR done when you moved in and see what the readings were, you should see on there if there is likely a problem.
But you only need 20 amp so why not fit a B20 MCB? The cheap plug in tester with loop will normally measure 1.9 Ω so the tester costs just £50 not £250 OK would need to temp fit a socket to use tester, but it would keep the cost down.
In theory to DIY electrics will cost more than getting some one in, due to the cost of test equipment and notification, we all known most people don't bother, and unless you injure some one doing the work, there is very little chance of getting caught, but for any one to say on an open forum you can break the law, is clearly wrong, so most people never ask "Can I".
