Electrical System Questions

My RV3 (Late eighties kit) has several rocker switches on the lower edge
of instrument panel. Are these switches still available from Van's and in
use today on newer RV's? They have spade terminals with crimped connectors. Any recommendations for a good low priced crimping tool for
the insulated connectors vans sells? The plane also has a master solenoid
controlled by the master switch. What is the advantage over just using a
Potter and Brumfield switchable (31 series) breaker as both the master switch and main breaker?

Thanks
Jim Miller

The terms "good" and "low-priced" very seldom coincide when you are discussing crimping tools. Anything made by Amp is usually pretty good. Anything at Radio Shack is not. You want a tool with ratcheting action so that you make sure that you crimp it all the way.

Remember that starting current probably goes through the master contactor. It's unlikely that you'll find a switchable breaker that can handle that current. Also, the wire from the battery is unprotected from the battery until the breaker / contactor, so you want that to be as short as possible. Short also helps with voltage drop when the starter is turning. If you run that wire into the cockpit and then back out to the starter, that might be enough voltage drop to require the wire size to increase.

Phil

Phil
What I had in mind is what I have put on my PA22-108 via 337. It does
not have the starting current thru the master breaker/switch. Using one
starter relay near battery the battery side of this solenoid tee's off a #8
wire for power to master switch and main buss. The starter gets it current
thru the solenoid and is in parallel to main buss. The master switch is a
35amp series 31 switchable circuit breaker.

jim miller said:

My RV3 (Late eighties kit) has several rocker switches on the lower edge
of instrument panel. Are these switches still available from Van's and in
use today on newer RV's? They have spade terminals with crimped connectors. Any recommendations for a good low priced crimping tool for
the insulated connectors vans sells? The plane also has a master solenoid
controlled by the master switch. What is the advantage over just using a
Potter and Brumfield switchable (31 series) breaker as both the master switch and main breaker?

Thanks
Jim Miller

Click to expand...

I picked up mine off Ebay. I got the original AMP PIDG crimper. There are usually always a few available on Ebay. SteinAir sells some crimpers that are less expensive, but equally effective.

bob

jim miller said:

Phil
What I had in mind is what I have put on my PA22-108 via 337. It does
not have the starting current thru the master breaker/switch. Using one
starter relay near battery the battery side of this solenoid tee's off a #8
wire for power to master switch and main buss. The starter gets it current
thru the solenoid and is in parallel to main buss. The master switch is a
35amp series 31 switchable circuit breaker.

Click to expand...

That'd work.

I guess my idea of a master switch is that it removes ALL power from the system. You might want to consider a fusible link at the battery for your 8AWG wire in case you have short between the battery and the breaker.

I don't know whether it's likely or not, but something else to consider is a locked up (welded) starter contactor. You'd have no other way to stop the prop from spinning, except to wait until the battery was dead. By then your starter will probably be dead too. Does this even happen?

I'm curious why you want to eliminate the master contactor?

Phil
Those are two good reasons to have a master relay. What led me to question
it was my PA22 doesn't and never had one as Piper designed it that way. The
mod I did just replaced a master switch and two glass fuses with a switched
breaker which was a great improvment. A master relay was never installed on a PA22-108 or any PA22 to my knowledge.

Thanks
Jim Miller