PDA

View Full Version : Trio AutoPilot Circuit Breakers


Bill Phillips
12-24-2009, 09:07 PM
Hello Fellow Builders, I have installed two Trio servos in my RV-8a. They are driven by the MGL Odyssey EFIS. Can not find the size circuit breaker needed even though the wiring diagram shows 22 ga wire. Who out there in builder land can help me this Christmas eve with such info? Hope to hear from you and have a merry and Blessed Christmas, Bill of Georgia

Bill Phillips
12-25-2009, 07:43 AM
Where in the Trio AP installation info does it require a circuit breaker size?

Sam Buchanan
12-25-2009, 08:24 AM
Hello Fellow Builders, I have installed two Trio servos in my RV-8a. They are driven by the MGL Odyssey EFIS. Can not find the size circuit breaker needed even though the wiring diagram shows 22 ga wire. Who out there in builder land can help me this Christmas eve with such info? Hope to hear from you and have a merry and Blessed Christmas, Bill of Georgia

Bill, if you are referring to the harness running from the EFIS to the servos, I don't recall ever seeing CB's on that harness (I've had several different autopilot systems in my plane). The signal/data wires are serial which is very low voltage--the power wire is 12vdc but I've never seen a breaker called out for it.

Rockyjs
12-25-2009, 08:48 AM
The note below the schematic on the Altitude autopilot says 3-5 amps on the power leads. As Sam said nothing on the serial lines.

Bill Phillips
12-25-2009, 09:24 AM
Sam & Rocky, I want to route the leads thur a toggle and CB so I can exclude them if something happened to a servo like a run away trim tab. Never flew an AP before and I'm a bit concerned about whom or what is controling my immediate fate, Ha. Thanks for the info, best regards, this fine Christmas morning, Bill

Sam Buchanan
12-25-2009, 09:35 AM
Sam & Rocky, I want to route the leads thur a toggle and CB so I can exclude them if something happened to a servo like a run away trim tab. Never flew an AP before and I'm a bit concerned about whom or what is controling my immediate fate, Ha. Thanks for the info, best regards, this fine Christmas morning, Bill

Bill, I understand your concern. I had to come to terms with this matter when I installed my first pitch autopilot.

The Trio Gold servos are amazingly good with all sorts of internal diagnostics to protect against unwanted events (I don't know how MGL integrates with these features). If the servo clutch is adjusted properly, you can easily hand-fly the plane even if the servo is still engaged.

I'm not familiar with how MGL controls the Trio servos--Trio's ProPilot has a single momentary pushbutton switch that will disengage both servos. If you want a belt-and-suspenders approach, you might install a good quality double pole toggle switch that controls the power lead of both servos. Once power to the servos is disrupted, the servo solenoids will drop out and your can fly the plane with no control drag.

Bob Ellis
12-26-2009, 01:20 PM
Hi Bill

I asked Jerry Hansen at Trio this very question, his reply:

"Hello, Bob:

Thank you for the inquiry.

We recommend #22 wire for all connections, and a 5 amp breaker/fuse.

If you have any further questions, please don't hesitate to contact us.

Best regards"

I plan to fit a double pole switch too as Autopilot master.

Regards

Bob Ellis
www.rv-8.co.uk

Fuselage 80% complete.

Rockyjs
12-26-2009, 06:12 PM
Hi Bob,
Since the EZ-Pilot has a switch on the unit and circuit protection I felt that that would be good enough. I did add a small mini-toggle to the Altitude autopilot/servo power using one of the mounting holes on the plate, since I didn't care for the unit being "on" all the time. As Sam said if there was a problem once the unit is off there is no control drag. If there was a malfunction on one of the servos the added switch gives you the opportunity to isolate just that system instead of a double pole switch that would "kill" both autopilots.

Rocky