SV-AP Panel Breaker Rating

[rvflyer]

The docs suggest a 4A breaker for the AP panel which I assume allows for 2 MAC trims.
If you only have 1 MAC trim (elevator) I assume the breaker should be rated at 2A. However, the Ray Allen docs suggest 1A is appropriate. Which is correct and how much current does the AP panel draw? I would not want overrated breakers.
Any help appreciated.

 

[mmarien]

The breaker is to protect the wire. There is nothing incorrect about putting in a bigger breaker as long as it will protect the wire. So put in a 5A breaker and a wire big enough (18AWG) to support that current and you are good.

The AP panel will not draw more then 4A so the breaker will never trip from normal use.
If there is a short, the breaker will trip before the wire will go up in smoke which is what it is suppose to do.

If you are concerned that the larger breaker will cause damage to the equipment by allowing it to draw more then 4A, that will never happen.

 

[rvflyer]

Thank you, I'm well aware of how breakers protect the wire, there is an apparent inconsistency in the various sets of documentation. I'd like to know if this is an omission or other.
The recommendation is that a load is no more than 80% of the breaker rating, dependant on the type of load.

FYI, 40 years ago I qualified as an electronics engineer, did you?

 

[Raymo]

FYI, rvflyer, mmarien is one of the most competent, knowledgable folks on this board. The information he provided is spot-on. No need to get defensive.

 

[rvflyer]

Thank you , not defensive, I've built, amongst others, 4 RV's.
Happy for my competence to be questioned, just prefer not to be spoken to like I'm an idiot!

 

[jakej]

Troubleshooting via email or phone is not easy, especially if one does not know the level of ‘experience’ (distinctly different from level of training) of the other person.  You need to go down to a basic level of explanation when troubleshooting & I usually state ( with phone calls) that because it hopefully lets the OP understand where i’m coming from  .  That way no one gets their face out of place. ;D
Oh, btw, I’m on my 40th RV & at least 30 other installations- no full on training & I find that helps a lot because I wasn’t taught to think a particular way & I find that really helps a lot, particularly with in the field experience, in troubleshooting issues that some trained people are not able to do.  All in all we need each other so I’d politely suggest we chill out and keep our [ch128526]. This is supposed to be a learning & fun industry whether your a aircraft builder or flyer or both 

 

[mmarien]

My apologies. I must have miss read the gist of you post.

Maybe table 98 on page 18-5 is what you are looking for. Power for the AP panel is supplied by the Skyview network.

 

[Dynon]

We try to provide reasonable guidance to people who do not fundamentally understand the function of breakers, how to size them, etc. They might not be exactly the same as an engineer might choose for their exact situation, circuit design, etc. I presume other manufacturers do the same, and those recommendations may not necessarily align perfectly because none of us know what circuits and loads builders may combine. We do have comprehensive power specifications starting on page 2-4 that should clear everything up and will allow an electrical engineer to formulate a breaker plan based on their own knowledge.

One point on the SV-AP-PANEL: Think of it as two devices in one. The Autopilot Panel half of the product (which is buttons, low current electronics, and backlight only) is powered by SkyView Network, and isn't separately protected. The other half of the product (literally on a different connector on the panel) is the trim motor controller. In that case, it's really the trim motor current that you're sizing the breakers for. As you'll see in the table, the trim motor power protection is "dependent on the trim motor chosen".

 

[rvflyer]

Thank-you everyone, it was a simple question, all I noticed was an inconsistency in the docs. It seems more effective to actually call the factory, it would be foolhardy to blindly follow a lookup table. It is a fact that Dynon have been known to produce faulty & problematic products. The consequence of an electrical fault in an aircraft may be significant- aircraft can bite hard when they go wrong. For comparison, look at Trig install docs, they are thorough and well written as are those of the Aerolectric connection.

 

[rvflyer]

Thank-you everyone, it was a simple question, all I noticed was an inconsistency in the docs. It seems more effective to actually call the factory, it would be foolhardy to blindly follow a lookup table. It is a fact that Dynon have been known to produce faulty & problematic products. The consequence of an electrical fault in an aircraft may be significant- aircraft can bite hard when they go wrong. For comparison, look at Trig install docs, they are thorough and well written as are those of the Aerolectric connection.

 

[rvflyer]

One more question, to you all, I note that some members are denoted experts. Can I assume them to be qualified/chartered engineers in electical/electronic engineering, specifically in the aerospace world? I would expect/ assume those experts to be experienced in circuit design/ power engineering specifically in the aerospace world which ain't quite the same as working on cars for example. No disrespect intended, but giving advice on a situation that might make for a dangerous aircraft seems unwise. I have a fair amount of experience with aircraft but on anything significant I consult with people that have relevant & current knowledge. I'd like to minimise the opportunites for lawyers to remove the shirt from mine or anyone elses back!

 

[jakej]

Three things here come to my mind here -
1. Your last sentence shows you don’t understand the ‘experimental aviation’ world - litigate if you think you can be successful.
2. I don’t know of any avionics manufacturer who hasn’t had an issue with at least one of the products they have produced, nothing is perfect no matter how they try. Name one that hasn’t had an issue.
3. May I suggest politely you do not tell us how qualified you are & how much we probably don’t know - it doesn’t go down too well with us ordinary folks.
No more from me on this particular post - IMO enough has been said & no more to gain

 

[rvflyer]

Well JakeJ, my qualifications were earned the hard way and your disrespectful and ignorant attitude makes me question your 'expert' status.

 

[airguy]

You seem to be asking an awful lot of basic questions for a subject matter expert who has built 4 RV's already (among others).

 

[Dynon]

I think the "expert" tag is automated, based on post quantity. So it may or may not denote an actual expert. I'll will volunteer that all of the "experts" in this thread do indeed deserve the badge - they know a ton about Dynon products and try to be as helpful as they can be. Please, everyone, let's try to keep the tone civil though. We haven't locked or deleted a thread in many years, and I really don't want this to be the first.

 

[rvflyer]

I called the factory, and as suspected, there is an issue here, the breaker should be less than 4 amps for 1 trim motor, 2amps is probably suitable. Based on the AP panel drawing .5A & a motor drawing upto .8A in during normal operation, ergo, 2A is likely to be appropriate. As they say 'read the question'. This idiotic tit for tat is likely to negatively impact the reputation of Dynon. It certainly invokes 'sales prevention' , I won't be making further purchases!