garden pump tripping RCD

These intermittent faults can be a real problem.

A couple of points though.

1) If the pump was leaking to earth and is connected by a SP switch then it would trip the RCD at all times via the N to earth leakage.

2) Plugs as isolators are very common, I suspect that most domestic central heating systems are isolated in this way.

3) A pump will not act as a generator if one leg (i.e. L) of the supply cable is disconnected. It does not matter what potential is generated by the pump spinning down if there is no circuit for it to flow through.


Have you carried out an insulation test on the pump itself?

Does the RCD trip if you stop the pump by pulling out the plug.

 

Hombrey,

Did u get a result on this yet, I have exactly the same problem, couldn't believe it when I stumbled across your post..