flyrotary@lancaironline.net Mailing List Archive

Al,

I don't know the current draw of the starter selenoid. The reason for the starter contactor is that most starter switches could not carry the starter current drain during starting. So a low amp switch is connect to the contactor which carries the heavy current draw for the starter. I think in aircraft use it is primarily for safety reason. If the solenoid should fail closed then the starter would remain engaged with the engine running and cause damage. With a switch activate contactor you remove all power to the starter thereby precluding that type of mishap.

Ed Anderson

----- Original Message -----

From: Al Gietzen

To: Rotary motors in aircraft

Sent: Wednesday, March 05, 2003 8:07 AM

Subject: [FlyRotary] Starter solenoid

What’s the steady-state current draw of the starter solenoid?

Why, in all of Bob Nuckol’s wiring diagrams, is there a starter contactor switching the heavy current to the starter? There is already a contactor in the solenoid. What am I missing here?

Al Gietzen