"Morgans" wrote in message
...

Bathroom fan switches are "not quite" up to aerospace quality standards.

Used the way it should be, failure of the switch shouldn't be a factor.

Put the transfer pump running off of a relay, that is hooked to a "full
tank" sensor. Even if you used a timer, like above, it would prevent an
over flow situation - if you set the timer for too long, too soon.

What was that quote about idiots and failures? I can't remember right now
but one cannot idiot-proof everything. I think adding a "full tank" sensor
would be overkill. The setup in the Emeraude I had (which went in killing
the pilot because of completely empty tanks) had a 20 gallon main and a 5
gallon aux tank. When the main got down to half, one would crank the "fan
switch" over to it's stop and it would dump the five gallons into the main
and then shut off, saving the pump and battery for the next time.

A simple setup and one designed to save the pilot's brains from overload so
he can deal with the lowering overcast he just flew into.



Rich S.