He's not much of an electrician if he doesn't know how but there are many out there who make the same mistake 
Prize goes to RF Lighting then - neutral to the RCD should be fed into the top not the bottom of the module as he has done.
to be frank, you need someone more competent to sort it.
The person who fitted it did not do a good job. It is not difficult to do one of these properly if you understand what you are doing.
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