Relay for Start Switch Circuit?

[mike.smith]

Yeah in theory I agree but apparently that Skytec starter solenoid pulls a bunch of current anyway. In the other thread that I linked above some folks were having pretty significant size fuses pop just from the solenoid, which is what started me thinking about all this. The Aerovee manual calls for 14 gauge wire so they must expect several amps at least!

I don't think it's simply theory. That's the reason for the existence of a solenoid; to isolate the high voltage from the switch and the cockpit. I have a 15 amp breaker that has never tripped. If there is that much juice going to the switch, perhaps something else is amiss.

I have a diode (1N4004, 400V (PIV), 1 amp) between the switch and the positive terminal on my SkyTec. It was there for a piece of hardware I used to have in the panel that isn't there anymore, but the diode remains. I have a diode across my master contactor, too. The diode provides protection from the collapsing magnetic field when the switch is turned off.

[n307tw]

Yes, in theory Mike is correct. Is this starter solonoid also pulling the starter motor pinion into engagement with the flywheel? I thought normally this action was a result of the starter motor itself energizing, the initial spin action engages the pinion.

Gordon,

The starter solenoid when engaged does in fact pull the pinion out to engage the flywheel. I ended up using 12ga wire for the starter circuit to be safe. It pulls close to 6 amps according to my on-screen amp meter. This is with the main wire disconnected from the starter and everything being pulled through the solenoid circuit. Maybe some of this is alleviated with the main heavy gauge wire connected but I haven’t tested that yet.

-Tim


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