In an earlier contribution to this discussion,
raden wrote:

In message , Set Square
writes

It would sometimes be useful to test a pump dry - by running it for
a minute or so -before fitting it, and I'm trying to assess the
consequences of so doing.

It uses water both as a coolant and as a bearing for the ceramic
shaft.

Thanks to everyone who replied. The general consensus seems to be that it is
a *bad* thing to run it dry - so I shall desist.

[One reason for wanting to test it dry is that I'm experimenting with a
delay timer - to keep the pump running for a bit longer than the boiler's
pump over-run logic (if you can call it that!) does it for. Specifically, I
want I keep it running during the period after the boiler stops firing but
before the over-run stat decides that it's getting a bit hot, and it had
better start the pump again. The timer is designed for an extractor fan -
but is supposed to work with loads between 25 watts and 200 watts - so I see
no reason why it shouldn't work with a pump - unless anyone knows
differently?!]
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.