power avionics master

[willerjim273]

 

 

1980 231k

 

Where do I find the bus that becomes hot with the avionics master? I read about some plastic piece on pass side. Anyone have a pic? What wires could I follow to that one.?

We are adding a bitching betty and I would like to have her not start bitching until I hit the avionics master. I also have a Davtron 655  OAT I need to power. Only place I can find is below pilot - under panel. However I cannot find any under there that are open/closed by the avionics master. 

Also, there are some inline fuses under the panel not labeled. As far as what items need to be run through the panel fuses, do we go with the "essential for safe flight" definition regarding what fuses have to be easily  accessible and reset-able in flight?  Betty is not essential for flight. 

To get to the back of the panel fuses, it looks like some de- riveting is required. Anyone have instructions on that one? Some people are like John Lennon- "let it be."

 

 

Tks

 

 

[cliffy]

Your A&P should have a manual with the wiring diagrams. Does he?

[carusoam]

The mysterious bus is usually on the back side of the mysterious circuit breakers...

 

Try the search function,  Somebody has pics...

+1 on discussing said additions properly with your A&P.

Having everything properly documented in the end will make you feel happier about your ship.

Best regards,

-a-

[N231BN]

The procedure for removing the CB panel is in the manual. Basically, in addition to the screws on the face of the panel there are two screws underneath the panel and there are two screws ahead of the door hinge on the side of the fuselage that need to be removed.

[willerjim273]

OK,

 

Thanks

He is not fluent in Mooneys. We will look for it. I see it in the wiring diagram, but no location reference that I can see. 

[Guest]

The “bus” referred to is all of the copper bars which tie all of the avionics circuit breakers together.  There will likely be several of them, one on each row of avionics circuit breakers.

The circuit panel layout should look something like this.

Clarence

 

[NicoN]

You may try to reach the lowest bus "bar" without removing the CB-panel. I did not try this. But removinge the CB-panel was far more work than expected.

The Avionics Master itself powers only a solenoid-

[PT20J]

10 hours ago, N231BN said:

The procedure for removing the CB panel is in the manual. Basically, in addition to the screws on the face of the panel there are two screws underneath the panel and there are two screws ahead of the door hinge on the side of the fuselage that need to be removed.

This is where to begin. If you are adding equipment, you should add a breaker for it. It might be better to have this done by an avionics shop as they are will probably do a neater job of it since that's what they do for a living.  

Skip

[Yetti]

The buss is on the comm breakers which is powered by a relay that is up on the starboard bulkhead near the firewall.   The relay is a normally closed relay. That is powered by the comm switch.   Power makes the NC breaker open.   Sometimes removing the CB from the panel give more room to work.