What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Flap Circuit Breaker

Robb

Well Known Member
The 5 amp breaker on my 7 started tripping the breaker today. It runs the motor for a few seconds then trips. It does more the flaps a few degrees but thats it. Ill troubleshoot it this week and see if its a motor or breaker? Doesn't seem to be binding anywhere. I didn't build it so I am not really familiar how it works. If its a motor are they readily available from Vans?
 
I have a 10 amp breaker on my flap circuit but was not able to find documentation on what it *should* be. May have gotten it off the motor itself.
 
10 amp breaker for the flaps

We recommend a 10 amp breaker for the flaps. Typically the flaps will draw a maximum of 5 amps under rated load, but if there's any binding in the flap linkage it can exceed this amount momentarily. Yes, the breaker should be sized for the wire it protects, but then the wire should be sized for the expected load, so it's kind of what comes first, the chicken or the egg. And of course, the wire size is going to depend on the distance between the flap motor and the voltage source. Use the sizing tables in the Aeroelectic Connection for wire size.
 
I've got 290 hours now on a 5-amp breaker for the flaps on the 9A with no troubles.

Just a datapoint, might very well turn out that I need 7.5 or 10 at some point. I generally use full flaps for every landing, retract on the rollout and park with them down, so they get exercised fully twice on every flight. I do pay very close attention to flap extension speeds though, so I'm not overloading the motor.
 
The stall current for the flap motor in a -7 is 14.49 amps. Now, we hope that the motor will never be fully stalled, but you can bet that the inrush current when you 1st press the button is pretty close to that figure.

The flap switch that shipped with my kit is rated at 10 amps, 250 volts.

There are a couple of data points for you; your choice on how to use them. :)

Charlie
 
I recently converted from manual flaps to electric. The flap motor from vans required a 10 amp breaker in the instructions. Works perfect.
 
If this worked reliably for a while and now trips the breaker, you should find the reason that it is now drawing more current. Increased resistance is a possibility and could point to grease migrating into the motor's brushes if you have an older flap unit.

Larry
 
Checked the motor and it all looked good. It was drawing just a little over 5 amps so I should be good. It was an easy task to change the breaker and check the wire size. Lucky for me a professional avionics shop did my panel everything was easy to get to. I just wish I had aileron trim!!!!
 
Flap motor circuit protection ?

As stated in this thread, Vans suggests a 10 amp fuse for a conductor that supplies the flap motor and other devices on the same circuit. It is also suggested above, that 5A breakers are known to ?pop? under some conditions and 10A breakers are common. Also, the wires on the motor appear to be about 20ga. / 5A capacity. According to Knuckles ( and B&C techs), breakers are generally more tolerant of surges and slower to ?pop? than fuses.

So, how do you fuse a circuit from the buss to protect a 10A breaker circuit that is protecting motor wires than are only rated for 5 A ??
 
Back
Top