Legality and safety of mains equipment

摘要

I have been a reader and subscriber of your magazine for many years.Recently,I disassembled the failed controller of a domestic rainwater pump and discovered something that I would consider dangerous.The Triac on the back of the controller board is connected directly to the Active conductor of the mains supply and turns the pump on and off.It is mounted on an Earthed metal plate that is in direct contact with the water delivered to the house.Is this legal and is it safe?(M.W.,Murray Bridge,SA)·That construction method is safe and legal.The metal plate is Earthed and the water is only making contact with the Earthed metal plate.The Triac would be an isolated tab type where its metal tab is not connected to any of the Triac pins.This isolates the Triac pin connections from the mains Active.