Panel went haywire???

[ragedracer1977]

Playing with the breaker right now, you might be right about it being bad.  It takes very very little pressure to make it pop.  Just the slightest tug and out it comes.  I have to pull pretty hard on all the other breakers

[ragedracer1977]

I'm no expert, but the shop that installed the narco was supposed to be.  

Found this at the connector.  I don't know that this had anything to do with it, but you wouldn't expect the people you pay as "experts" to do this.....

The com wires were all unshielded.  There was even a molex connector in line near the audio panel that carried power and audio.  

Either way, this needed to be fixed.  

 

[Oldguy]

Had to use the "Confused" emoji since I could not find the one for "Holy $h!t".

[EricJ]

5 hours ago, ragedracer1977 said:

I'm no expert, but the shop that installed the narco was supposed to be.  

Was that an AZ shop or before you bought the airplane?

[ragedracer1977]

2 hours ago, EricJ said:

Was that an AZ shop or before you bought the airplane?

Before I bought it.  I tried looking them up, but the shop isn't in business anymore, stuff like that is probably why.  

[chriscalandro]

Sounds like there might have been a few things going on, I wouldn't think a swelling battery would pull that much power, seems like it might just be a coincidence.

 

My guess is something in the radio shorted and started pulling power, and eventually burned out.  Did you say the main buss breaker might be bad?  that would explain why that went before the radio breaker, but it seems like the radio breaker should have gone too...

[ragedracer1977]

1 hour ago, chriscalandro said:

Sounds like there might have been a few things going on, I wouldn't think a swelling battery would pull that much power, seems like it might just be a coincidence.

 

My guess is something in the radio shorted and started pulling power, and eventually burned out.  Did you say the main buss breaker might be bad?  that would explain why that went before the radio breaker, but it seems like the radio breaker should have gone too...

It's very confusing.  It may have been a combination of things.  It may just be that it's a bad alternator breaker (it's WAY too easy to pull out, you just sorta tap it and it pops), and the narco was having a bad day and blew up when I sent power to it again.  Looking at the ammeter now, sitting in the pax seat, it was probably at about 40 amps, not more. That shouldn't be enough to blow the breaker. The parallax from the pilot seat makes it look higher

[PT20J]

Interesting problem and good data on the issues you found and the troubleshooting.

First, the ALT breaker should not trip unless one of three conditions occur: 1) the alternator or it's wiring shorts; 2) the breaker is bad; 3) someone replaced the alternator with a unit capable of putting out more current than the approved original. Since your alternator works, I would suspect 2 and verify 3.

Nancy Narco says (remember her?) that your Com 2 was installed by a hack. I'd look into whatever else this shop did and get it all cleaned up. But it also sounds like the Narco is toast since it didn't work on the bench. The crappy wiring may not have been the issue. The interesting question is why the Com2 breaker didn't pop. It might be defective also. If you had a weak ALT breaker that tripped early, and a Com 2  breaker that didn't pop, and a hard short in the Narco, you might get the symptoms you have. 

This will be a "peel the onion" sort of troubleshooting exercise (frustrating, but better than intermittents!). You're on the right track and doing the right things so far. Keep at it and you will get it solved.

Skip

[ragedracer1977]

A new breaker is on order.  I think this is a good place to start.  The alt breaker pops out with almost no effort.  I broke my fingernail trying to pop the breaker right next to it.  Excuse the dirty fingers.  Old airplanes do that to you!

[carusoam]

A highly sensitive tensile strength gauge you got there Brice!

CBs should have a feelable click to them.

The ones that carry larger loads continuously have a tendency to wear out in 40+ years...

My C wore out the landing light CB... I noticed it the same way as you... a very light click...getting it replaced was interesting to see the difference...

Note for Skip... @PT20J... Check the spelling on the label above... is that a Bus with one or two ‘S’?  I am spelling challenged and looking for a way to solve this one.  

Best regards,

-a-

[Yetti]

On 4/14/2019 at 1:21 AM, carusoam said:

Note for Skip... @PT20J... Check the spelling on the label above... is that a Bus with one or two ‘S’?  I am spelling challenged and looking for a way to solve this one.  

Best regards,

-a-

Do a google search for B+ Buss bar.    I think lazy people drop the second s.   Maybe kings english vs the colonies

 

http://www.freepatentsonline.com/6015302.html

[PT20J]

15 hours ago, Yetti said:

Do a google search for B+ Buss bar.    I think lazy people drop the second s.   Maybe kings english vs the colonies

Electrical term is bus. Buss is a kiss. 

https://www.merriam-webster.com/dictionary/buss

 I was admonished about this in my first engineering job out of college.  

[Yetti]

32 minutes ago, PT20J said:

Electrical term is bus. Buss is a kiss. 

https://www.merriam-webster.com/dictionary/buss

 I was admonished about this in my first engineering job out of college.  

Most people don't know what B+ means or that electrons flow from negative to positive.   I have seen it written both ways all my life.  I have other things to wrapped around the axle about.

[PT20J]

20 minutes ago, Yetti said:

Most people don't know what B+ means or that electrons flow from negative to positive.   I have seen it written both ways all my life.  I have other things to wrapped around the axle about.

Electrical engineers use “conventional current” -flows from positive to negative. Yes, of course we know that electrons flow the other way, but the convention predates that understanding. That’s why the emitter arrow on a transistor is in the direction opposite electron flow. 

[EricJ]

11 hours ago, Yetti said:

Most people don't know what B+ means or that electrons flow from negative to positive.   I have seen it written both ways all my life.  I have other things to wrapped around the axle about.

The Navy and the FAA were holdouts of expressing current in the direction of electron flow, but their conventions were backwards from the rest of the universe (thanks to Ben Franklin).   The FAA is now apparently kind of neutral or transitioning to more common convention, and I don't know how the Navy teaches it these days, i.e., whether they're still "backwards" or not.

And we'll probably have the difference between whether sqrt(-1) is i or j for a much longer time.