there's 2 reasons for shocks
1) No earth or a poor earth to the appliance
2) nylon carpetting and static which is actually YOU giving the appliance a shock
You need to make 100% sure the appliance has a good earth because if it hasn't it is potential lethal and could harm/kill someone!.Did the appliance engineer do an earth loop inpedance test using a D lok meter.this would give you an accurate reading on your earth supply.He can also do a resistance check from the plug to the appliance case but he will need a meter that can work down to 2 decimal places.a good engineer will know what this means straight away,a not so good one will not!
ck
October 2010