The only thing I can think off
would be something like a fault diode, which would send the current back
down the wire, I know you use diodes in small circuits, but i'm not sure
they would be used in pumps etc.
Because a motor actually generates its own electricity, it's just like a
dynamo, so a diode has to be put in place to stop it flowing backwards.
Its true what they say, a little knowledge is a
dangerous thing. First of all we said years ago on our
rcd page "If it is a submersible pump throw the pump away DO NOT
attempt to repair it. A pump may cost several pounds and can be replaced, A life
is priceless and can not be replaced."
Secondly the part regarding generating its own
electricity and diodes regarding pond pumps is absolute rubbish.
What amazes us, is the fact the first person wanted to
repair the pump, the second person had no idea what he was talking about
either.