12 hours ago, Goanna said:

But as you can see from the pic, I have bigger problems here. With the main off, only one circuit, the GPO that the tv runs from, shows ten volts! So, there is a screw piercing somewhere or something like that. When all the switches are on with the main off, they all show 10 volts, because of the live bar. As well, the consumer unit box gives a shock, although mild.

 

I see no issue in your measurement, with everything off that's more than likely just capacitive pickup, nothing to worry about.

 

If you are receiving a shock from anything measure between it and a big screwdriver in the lawn (true earth) and see what you measure then.

 

I do see that you have an RCD in that box, but it doesn't seem to be connected.

 

There appears to be a link (brown) between your neutral bar (bottom) and the ground bar (top), this would stop your RCD working properly (possibly why it's not connected) and also potentially could be the cause of your mild tingle. You should remove that link.

 

EDIT Actually, you need to get a sparks who knows what he's doing to do the job properly (I know, easier said than done).

 

EDIT2 Oh, if you've not had your PEA inspection there's no way in heaven or earth that you will pass. You are missing a properly configured MEN link, functioning RCD, ground rod and grounded outlets.

 

Have a look at this PEA document (in Thai but plenty of pictures) for how they expect it to be done http://crossy.co.uk/Handy Files/groundwire.pdf note particularly how the incoming neutral is routed via the ground bar, this is how MEN is implemented here. If you still have the instructions for the breaker box you should read them.

Thanks Crossy.

I built a large workshop. It has a couple of welders and various other power tools. My wife's uncle is a good electrician and he advised us to install a bigger meter, 15/45. We had to install larger wires from that new meter to the workshop and house.  If I remember correctly we paid about 4,000 baht for the meter change. The charge per unit of electricity did not change. Both the shop and house have 63 amp breaker boxes.