Although I have spent almost forty years in the electronics/control engineering industry I am not an electrician and, therefore, don't claim any sort of expertise with domestic electrics. With that in mind, I would be grateful (as I have been a number of times before) for the advice of those here with more knowledge and experience than myself in these matters.
My first question relates to a problem with our cooker - a bog-standard, inexpensive Creda 'Expression'. For some little while two of the hotplates have had the annoying tendency to cause the RCD in the CU to trip about once in every 5 or 6 times they were switched on from cold (never if still warm from having been used a short time previously).
I remember, that when doing some PAT testing a few years back, an incidence of some portable cookers, with similar hotplates, continually failing insulation tests when cold - if switched on for a while before testing they would pass ok. Upon detailed investigation, it was decided that there wasn't really a fault and we just made sure that they were run for a short while before testing.
With this in mind, I decided that my cooker probably wasn't faulty but that for some reason when cold there was just sufficient earth-leakage current to cause the RCD to trip. I therefore decided - particularly as we intend to replace the cooker fairly soon - to connect it to the non-RCD side of the CU. I did this about two weeks ago and there have been no problems.
My question is: was this an acceptable thing to do?
My second question is about earth bonding in a toilet/shower room that I have built at the rear of my garage. The room contains a shower cubicle, with 8.5kW electric shower, a toilet and washbasin , and a small electrical hand-wash unit. There is no hot water supply to the room, just a single 15mm cold water supply.
Can anyone tell me what type of earth bonding is required?