There should still be enough L to N voltage which operates the RCD function, so I'm not sure that scenario would necessarily cause the RCD function to fail to operate.
Should or definately will be? Would you be willing to gamble your life on it? BS7671 seems to err on the side of not! I have come across RCBOs where the RCD has failed before too.
There is a possibility with TN-C-S that this situation could occur, but I've found RCDs always operate on a short to earth.
Also the situation described would not be affected by replacing a B curve with a C curve.
How do you know if the RCBO has tripped on the RCD or the MCB side of it? The B curve and C curve are to do with the MCB side of things, the efli must be low enough, in a TN system to disconnect the MCB side of things. These are the figures are given in BS7671.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local
