Originally Posted by Mark33
Yes, I commented on this thread. For the reason you?re pointing out I?m installing duel relays running in parallel with each other. Each fuel pump will have it?s own relay but will also be able to be powered by the opposite relay. Each fuel pump will also be powered by its own separate circuit breaker.
Don't forget that a scheme like this will also require switches to activate each pump. You will need a method to test that the b/u pump is operational at Run up. I would also be concerned that BOTH pumps are run through one common relay. If that relay fails, you stop moving air unless there is a backup power route to the pumps. As shown in the pic, I would be concerned with that design. In theory, a failed relay should still make the NC connection, but you are banking a lot on that fact.
N64LR - RV-6A / IO-320, Flying as of 8/2015
N11LR - RV-10, Flying as of 12/2019
Last edited by lr172 : 11-10-2020 at 07:34 AM.