Will Diode Prevent Backfeeding of Transfer Pump

Updated 09/05/2018 | Published 09/04/2018

Question:

I have a reversing diesel fuel transfer pump which transfers fuel between two tanks on a boat. I need to add a shut off valve to be actuated opened whether left or right power feed is energized. If I connect both left and right positive feeds to the “in” and connect the shut off valve to the “out”, will this diode prevent one power feed from back feeding to the other attached to the “in” side? I will of course need to attach the cut off to ground.

asked by: John

Expert Reply:

The simple answer is yes, the Roadmaster Hy-Power Diode # RM-790 will prevent backfeeding because they allow electrical current to flow in one direction only.

There is limitations to the power the diode can safely handle; it has a maximum load of 85 amps at 24 volts per diode so you need to ensure you do not exceed that capacity for it to work.

expert reply by: Kyle S