is empty
Completely agree, that there is probably more risk of running out of electrical
power then loosing both pumps. I understand that the output of one pump will
be enough even while departing. For those who missed something: In the new
serial
pumps drawings are check valves parallel to the pumps.
Thanks all non-lurkers for bringing up ideas and facts. The blocked fuel supply
made me think. If both pumps are running, as at departure, and they are in
parallel,
the flow will be more then twice as needed. If there is some half-blockage,
like Bob Harrison experienced, this increased fuel flow could more easily
suck in more debris and lead to a full block.
My solution for having (almost) always electricity to drive at least one pump is
to have 2 completely independent electrical systems. That is the original
generator,
regulator and (small) battery, and a second generator with built in regulator
and separate battery. Both pumps and the avionics will be wired to 3
position toggle switches, pos up circuit one, pos middle off, pos down circuit
2. At departure and landing pump one will be on circuit one, and pump 2 on
circuit
2. Power to the pumps will be indicated by a led.
I am still thinking about a relay system that cuts the generators and avionics
off, while connecting both batteries to get maximum cranking power at start.
Will
probably decide against it, because the extra components will add error
possibilities.
Kind Regards,
Jos Okhuijsen
----------------
|