Bob, I agree with your point on the fuel pump switch as a single point
failure. Bob Nuckolls points out the same situation for avionics master
switches and recommends that if you install a avionics master that you

add

an alternate/emergency switch in case it fails. I plan to have a back up
switch installed for avionics master and for fuel pumps. But for normal

ops

I prefer to use a single switch that toggles between left and right

pumps

and switches the selector at the same time.

  Good to see that someone else is considering this type of system - it
cant be totally off base if someone else is planning to go this route.

Mike Wills

Bob, I was also concerned about the possible failure of switches crucial to
the operation of the fuel and ignition system.  I purchased some rather
expensive toggle switches designed for hostile environments and with a
rating of 200 % of the DC (not AC)  current flow I estimated I needed.  Each
toggle has three positions,down-off, center-battery 1 (main) and up-battery
2 (aux) for redundant power sources.

However, I was still concerned about the non zero probablity of a switch
failure, so I wired a 20 amp circuit breaker  between the battery bus and
around the EFI and Ignition switches direct to those systems.  The circuit
breaker (normally open)  is located on the left hand side of the panel where
I can quickly reach it an push it in should I need to.

 The switches are normally operated in the center position (Main Battery).
I have the three crucial switches in a row.  1. Ignition/EFI Power 2. Aux
EFI Fuel Pump and 3. Aux CPU (in Tracy's ignition module).  My emergency
reaction is to throw all three switches (Simultaneously)  from the center
(main Battery) position to the upper position (Aux Battery) selecting the
aux power source and the alternate igntion CPU.  I also push in the 20 amp
circuit breaker.

Ed

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