One Common Circuit Breaker (Fuse) for Intercom / Intercom Panel/ SV COM Panel

[RV7Builder]

Hi everybody,
planning the installation of our Dynon System I wonder if it makes sense spending 3 circuit breakers (5A) for the communication system, or one would be enough.
In my Opinion, if the SV Com is out of order , the Com Panel and Interocm is useless anyway ?
What do You think about that, or how did You realize that ?

Nice greetings David

 

[jnmeade]

I am going to put the T25 and the Intercom on the same 5A CB. The load is well within the rated range. Note Dynon suggests 20 AWG for the radio.

 

[Marc_J._Zeitlin]

planning the installation of our Dynon System I wonder if it makes sense spending 3 circuit breakers (5A) for the communication system, or one would be enough.
In my Opinion, if the SV Com is out of order , the Com Panel and Interocm is useless anyway ?

Personally, I'm not a fan of doubling (or tripling) items on a single CB or fuse. It's more difficult to debug/maintain that way, and as you indicate, you lose two things if the breaker/fuse pops.

In this particular case, if you only have one COM and the COM dies/pops the CB/fuse, the Audio Panel or Intercom aren't going to be much use for communicating with ATC or other aircraft, but they'll still allow you to talk to the other folks in the airplane.

If the Audio Panel / Intercom dies/pops the CB/fuse, most of them will pass through the pilot headset and COM 1 signals, so that the pilot can still communicate with ATC or other aircraft.

In either case, these both seem like useful functionality to me in the case of a failure of one but not both components. So I would (and have) put all my components on individual fuses.

My $0.02.

 

[RV7Builder]

Tahnks for Your fast answers. May be a good compromise would be Com and Com Panel on one fuse, and one separated for the Intercom.
I guess the Com Panel has no function without the Com, although i could use the intercom for comunication with the Copilot, as You mentioned.

Nice greetings David

 

[jnmeade]

As always, we should probably cite where we are coming from.

I guess David is building an RV7, which if I remember correctly is side-by-side. I don't know how many radios he is putting in. Internal communication is probably not as big a factor to me with a two-place side-by-side airplane.

When I answered, of course I had my own setup in mind. I am building a small tandem aircraft with small panel size so space is an issue. Figure 194 of the AG installation guide shows the com panel powered through the same 5A cb as the com and that is how I am wiring mine. The intercom may be wired separately although Dynon suggests the load is so low one may wish to piggyback on another cb, which I decided to do and picked the com cb because it has a light load.

My plane is very deliberately being built for me to fly in a 30 miles radius around my farm solo, so I have all that in mind as I am (as we write) wiring my panel including the com functions. My panel is built hinged so it is very easy for me to flop the entire panel down and see and touch every cb and wire leading to it if I need to troubleshoot or modify (not in flight, of course ). My radio is way back near the antenna behind the passenger.

No doubt there are many very valid installation schemes and I won't defend mine, simply offering what I am doing and why for anyone else's consideration.

 

[Brent Dana]

I dont ever understand why someone might spend in excess of $20,000.00 on a system that you strap your ass too at 10,000 feet, and the lives of others and there is even a question as to 60.00 worth of circuits? Just saying, guess I could not look at my panel ever and think yep, i did it cheap! Just my 2 cents. Obviously I dont! Spent in excess of 100 hrs and 1 yr designing my panel, so it would be done right the first time!

 

[jnmeade]

Brent, it seems your comment is an attack on the concepts expressed in my post and by inference a direct attack on me. Thanks for your thoughts. I'm happy for you that your like it your way. I am happy for me that I like it my way. You stated your position very plainly and forcefully. Mine was stated above and needs to reiteration. Happy flying.

 

[Brent Dana]

Brent, it seems your comment is an attack on the concepts expressed in my post and by inference a direct attack on me. Thanks for your thoughts. I'm happy for you that your like it your way. I am happy for me that I like it my way. You stated your position very plainly and forcefully. Mine was stated above and needs to reiteration. Happy flying.

Sorry, not an attack. But was critical..,As an appraiser, I tend to see things that are not the way they are suppose to be as problems, and as such, I tend to speak negatively. Will try to curb that here. For resale value, spend the money on the little things, and you will get the most money for an item. Just a fact, I have come to appreciat.