[riobison]

Help

I have just bought a RV4 and I?m trying to figure why there is a toggle switch for ?Gen? and another one for ?Alt?

It has a 0360 A1A and I?m certain that it has an alternator on it.

So why an Alternator switch and a Generator switch?

Thanks

Tim

 

[Mike S]

While this is an almost impossible question to answer, due to the fact I did not built the plane----and only the builder really knows the answer-----I am going to take a stab at answering your question.

A possible explanation is that when originally built, the switch labeled Gen controlled the charging device, and then later a mode C encoder was added, and the switch for that was labeled "Alt"

Really, you will have to contact the person who installed the switches, or trace out the wire runs---or maybe you can get lucky if you can not figure it out by switching things on and off, and watching what happens when you do so.

Good luck...........you may need it.

 

[jim miller]

Tim
I would trace each back to see what they hook-up to. I also have a question
on same subject. My RV3 has a alt switch to disable field to alternator but
no way to turn off alternator output to buss as the major buss circuit breaker
is the W58 series with no means to trip manually. I have heard that alternators can keep going even if the field switch is opened, operating on an
induced current. Is this true? I have a master relay that can remove battery
from buss but not the alternator unless the field switch can do the job with
certainty.

 

[Jaknjoan]

ALT

If you happen to have a TruTrak Altitude Hold, that 3/4 inch square on-off button says "ALT" on it.

 

[MCA]

Tim
I would trace each back to see what they hook-up to. I also have a question
on same subject. My RV3 has a alt switch to disable field to alternator but
no way to turn off alternator output to buss as the major buss circuit breaker
is the W58 series with no means to trip manually. I have heard that alternators can keep going even if the field switch is opened, operating on an
induced current. Is this true? I have a master relay that can remove battery
from buss but not the alternator unless the field switch can do the job with
certainty.

Jim,

Most automotive internally-regulated alternators DO have this failure mode. Any externally regulated alternator (such as B&C) does not, and Plane Power says they have eliminated this failure mode as well. You can install a contactor (controlled by the field wire) on the b-lead but frankly I'd just get a proper aviation-specific alternator instead. Then you are assured that turning off the field switch also turns off the alternator output. My 2 cents...