All,

Elsewhere on the list we are having an, I hope, interesting discussion on protecting switch/relay contacts with snubbers. This separate note is for the starter and master solenoids which are additionally used on the gear pumps by Lancair.

You builders probably received a snubber diode packaged with your starter/mag key switch. This is the certified practice to protect the switch from the relatively large energy the switch sees when the starter solenoid is de-activited. This is a time proven method of protecting against this failure mode. For those of you with the conventional diode in place, rest easy as it is the proven solution. The starter solenoid is more highly stressed when it breaks the starter current than the hydraulic solenoid is when it breaks the pump current so rest assured again that a conventional diode is safe here also.

This note is just to insure we don't get lost in the weeds created by the far more complex subject of protecting smaller relays.

As always... hope this clarifies and helps. Fly safe.

Jack Morgan