Thanks, and yes, I do. The float switch sends power to both pumps, or doesn't, to keep the header full. When I add a bypass (switch) around the float switch that will send power to the two transfer pumps, and I will have to then use the transfer pump switches to manually myself to keep the Header full. Terrence
Sent from my iPad
Terrence,
I suggest you have individual switches for each pump that operate totally
independent of the float circuits.
Grayhawk
Angier,
Thanks for that experience, which made me realize I need
a switch to bypass my header float switch, to be able to transfer fuel
manually in case the float switch fails in the Off position.
This LML list
is a good thing.
Terrence
Sent from my iPad
On Mar 22, 2013,
at 9:15 PM, "Greenbacks, UnLtd." <N4ZQ@VERIZON.NET> wrote:
>
About 20min into todays' flight and with the transfer pump switches set to
auto, the system failed. Actually it had failed before takeoff but I was
unaware since the header tank was full on takeoff. I observed the sight gauge
level drop to its normal pump on level and kept falling. The EI fuel gauge for
the header tank agreed and kept falling. Normally the pumps come on
automatically at about 7.5gal but not today so I continued the flight and
operated the transfer pumps manually for the 2.5hr flight. About 5 min out
from landing I again turned on the transfer pumps manually and this time
forgot to shut them off. :-(
> Needless to say fuel was being pumped
overboard as I taxied into the hangar....
>
> So what went wrong?
The auto transfer system is controlled by a solid state relay from Perhelion
Design and it works great.
> However, the system failed due to the fact
that one of the leads to the relay from the buss had somehow slipped off its
terminal on the relay(these terminals are pointed down in this installation).
A female spade connector that was obviously just loose enough to wiggle itself
off, did so. In the end, a simple fix but it reinforces the point that none of
our building work should be taken for granted. Now the two power leads to the
relay are secured with clear heat shrink as well as lacing tape.
>
> Angier Ames
> N4ZQ
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