Panel went haywire???

[ragedracer1977]

Flying home from Texas yesterday.  Uneventful from SSF to PEQ.  Departed PEQ headed for DVT.  Somewhere past El Paso, I noted that the battery voltage was 11.9v.  Hmm.  Alternator is on, annunciator is off.  Find the alternator breaker popped,  I push it back in, ammeter showing a near 50 amp draw.  Maybe it’s cause the battery is low? Breaker pops again.  Well, this is a problem.  I start working out where I’m going to deviate.  El Paso seems the best bet, it’s sunday afternoon, and maybe there’s a mechanic there, not much between El Paso and Phoenix... I know I’ve got battery power for comms currently, and a backup handheld, so I start troubleshooting.  I turn off every switch, pull every breaker.  Push the alternator breaker back in.  Turn on alternator switch,  OK, battery is charging.  Not seeing hardly any draw on the ammeter. Start turning on all the lights.  Still ok.  Push 430 breakers in.  Still ok.  Push G5 breakers and associated breakers in.  Still good.  Push comm 2 (narco ncs812 breaker).  Narco comes on, ammeter jumps way up, narco goes blank and ammeter drops back to normal.  I pulled the narco breaker back out.  Put in all other breakers.  We’re good. Kept on towards Phoenix, modifying my route to keep airports fairly close, and I-10 under us for a while.  Made it home fine. 

So, the narco seems to be dead.  We pulled it out and hooked it up to a bench power supply and tried to turn it on. It stayed blank but was pulling under 1 amp.  Put it back in the plane and tried the “dead display” tuning function.  No joy on any frequency. 

How is it possible a nav comm pulled 30+ amps??  And didn’t pop the 10amp breaker it’s on? 

[carusoam]

It’s not where we’ve been that is important...

It’s where we are going... (Nice pirep though, excellent trouble shooting!)

 

Unfortunately, the Narco is probably not going with... for the rest of the journey...

Now to the thread with all the nicely straightened pics of used hardware choices... (I did the straightening, I have nothing to do with the pics of great hardware...)

You have been approved to leave the Narco... (Narco was my radio version of the champion spark plug... simple crappy nylon gears that would break, and the company could swap them out for less than a million dollars... so it seemed.)

Need a hand finding a replacement, Brice?

Best regards,

-a-

[ragedracer1977]

3 hours ago, carusoam said:

It’s not where we’ve been that is important...

It’s where we are going... (Nice pirep though, excellent trouble shooting!)

 

Unfortunately, the Narco is probably not going with... for the rest of the journey...

Now to the thread with all the nicely straightened pics of used hardware choices... (I did the straightening, I have nothing to do with the pics of great hardware...)

You have been approved to leave the Narco... (Narco was my radio version of the champion spark plug... simple crappy nylon gears that would break, and the company could swap them out for less than a million dollars... so it seemed.)

Need a hand finding a replacement, Brice?

Best regards,

-a-

I'm really leaning towards an SL30.  it would fit nicely in my radio stack, really freeing up the co pilot panel. 

[takair]

Must be bad Narco week.  My MK12D decided to stop transmitting this weekend.  Must have been over 30 years old and very reliable.  

[Ned Gravel]

Don't tell me that! 

I still have a 12D in mine as NAV/COM 2.  480 is NAV/COM 1.  I would be OK (safe and airworthy) if #2 goes, but, but even with a handheld backup - the holes in the swiss cheese are starting to line up.

 

 

[1964-M20E]

On 4/9/2019 at 5:05 AM, ragedracer1977 said:

I'm really leaning towards an SL30.  it would fit nicely in my radio stack, really freeing up the co pilot panel. 

There is a place in the North East that still repairs Narco radios I sent him mine a few years back.  Probably the cheapest route but then you have the SL30 or it's newer replacement as well.  There seems to be several manufacturers out on the market right now.

[ragedracer1977]

3 hours ago, 1964-M20E said:

There is a place in the North East that still repairs Narco radios I sent him mine a few years back.  Probably the cheapest route but then you have the SL30 or it's newer replacement as well.  There seems to be several manufacturers out on the market right now.

It seems my only real option is the SL30 or an Icom com only radio, at least to fit where I want it.  

[EricJ]

You may have had more than one problem, and it may be that whatever the problem was is what killed the Narco.   Fingers crossed that replacing that heap fixes everything, but I'd keep an eye out for other contributors.

 

[ragedracer1977]

3 hours ago, EricJ said:

You may have had more than one problem, and it may be that whatever the problem was is what killed the Narco.   Fingers crossed that replacing that heap fixes everything, but I'd keep an eye out for other contributors.

 

It might have been the stratus! 

i has it plugged into the cigarette lighter.  Noticed after the flight that the battery was significantly swollen....

[MIm20c]

4 minutes ago, ragedracer1977 said:

It might have been the stratus! 

i has it plugged into the cigarette lighter.  Noticed after the flight that the battery was significantly swollen....

I’d get that changed out. Not sure if it one that can explode (however slight still would not be good). 

Side note a used sl30 is listed on BT for a reasonable amount. 

[ragedracer1977]

32 minutes ago, MIm20c said:

I’d get that changed out. Not sure if it one that can explode (however slight still would not be good). 

Side note a used sl30 is listed on BT for a reasonable amount. 

Ohh yeah.  It's out. 

I'm now considering just going comm only.  I don't know that I really want to invest $5k in a new radio and indicator when I only ever use it to get the ATIS.  

[mark21m20c]

 what is the circuit breaker reset procedure for mooneys ? 

[ragedracer1977]

1 hour ago, mark21m20c said:

 what is the circuit breaker reset procedure for mooneys ? 

I don't know there is one, but I'm sure someone will chime in if there is. 

Best practice is to reset it no more than once.  I fully admit I did it twice. If it had popped a 3rd time, I was diverting.  But I learned something.  

Next time a main breaker like that pops, I'm going to pull all the breakers first, and then reset one at a time.

[mark21m20c]

OUR Mooney is a 1967 and the manual is very slim. 

[Marauder]

OUR Mooney is a 1967 and the manual is very slim. 

If you are taking about the Klixon style. I would only reset it once and if it pops again, leave it out.



I have replaced a number of these breakers over the 28 years I have owned my F. They seem to wear out periodically. Someone once told me to “exercise” them periodically and to pull them out and reset them. I do this about once a month and it does seem to have eliminated the premature demise of them.

I do know on some planes, there is no switch and they use these breakers as the switch. Not an expert on them, but based on my experience with them, I tend not to trust them.


Sent from my iPad using Tapatalk Pro

[Paul_Havelka]

29 minutes ago, Marauder said:

I do know on some planes, there is no switch and they use these breakers as the switch. Not an expert on them, but based on my experience with them, I tend not to trust them.


Sent from my iPad using Tapatalk Pro

 

Due to how circuit breakers work, heat derived from the current draw that correlated to the trip curve, it is very detrimental to their lifespan when they are used as switches. Unfortunately this is a necessary evil in some a/c. That being said, it appears that the above model of klixon cb has a life expectancy of 5,000 cycles at 30 vdc. 

 

To the OP, with that kind of draw and with the swelling of the one particular battery it would seem that you potentially have a hard short somewhere in the panel and before I would install any new equipment or operate the a/c I would have a meter put on all of the power leads, starting with the faulty circuit, until you were sure that there was not a short to ground or found the culprit.  I would look for any chafing on any wire looms. It is feasible that you had a slight short that caused your stratus battery to bulge and the Narco to act up initially and that it continued to get worse. And with how trip curves work, if your previous flights were not long enough for the cb to trip then the problem could have been ongoing for quite a while. 

 

Does the cigarette lighter and Narco happen to share a circuit or even just a common/ground?  

[ragedracer1977]

Narco and lighter share a similar ground, they're both grounded to the panel support.  Different bus bars for power.

I flew 8 flights in the previous 5 days.  1 of 4 hours, 1 of 2.5 hours, several right around an hour, the flight immediately preceding (engine didn't even cool down) was 2.5 hours 

[0TreeLemur]

19 hours ago, mark21m20c said:

OUR Mooney is a 1967 and the manual is very slim. 

There is a 1977 M20C manual you can download that is considerably more detailed.   A few of the V-speeds are different (Vfe is the big one), but you can edit those.   I have the '67 manual in my bird, but the '77 manual is the one that is within reach.

[DXB]

Weird problem, and great job isolating it in flight - not sure I would have been as clever.  The SL30 is a great unit (I love mine) but it's old.  These supposedly will be available in July for similar cost - in case you want to fly with 1 radio for a bit.  

https://www.aopa.org/news-and-media/all-news/2018/july/23/trig-avionics-previews-2019-releases

[mark21m20c]

21 minutes ago, Fred₂O said:

There is a 1977 M20C manual you can download that is considerably more detailed.   A few of the V-speeds are different (Vfe is the big one), but you can edit those.   I have the '67 manual in my bird, but the '77 manual is the one that is within reach.

Thank You !!!

[Yetti]

On 4/9/2019 at 12:45 AM, ragedracer1977 said:

How is it possible a nav comm pulled 30+ amps??  And didn’t pop the 10amp breaker it’s on? 

because the breaker is bad.  They do that.  Pretty common in AC breaker boxes.  Usually corrosion or a bit of welding has happened.   The way your radio failed is probably that the power supply went bad with a transistor or cap letting loose.  Sometimes they direct short when they go.

[PT20J]

So if I understand correctly, three things happened:

1 The ALT breaker tripped

2 The Stratus battery is swollen

3 The Narco radio fried.

The alternator shouldn’t normally be capable of putting out enough current to trip the ALT breaker. The purpose of the breaker is to isolate a fault in the alternator or its wiring from the battery. 

A swollen Li-ion battery is indicative of over charging which could be due to over voltage.

Newer avionics will withstand a wide range of bus voltages - usually about 8 to 33 VDC. The old Narco is less tolerant of over voltage. 

Did you notice the bus voltage after you reset the ALT breaker? This might be a voltage regulator/alternator problem. Hard to tell without doing some troubleshooting. 

Skip

[ragedracer1977]

16 minutes ago, PT20J said:

So if I understand correctly, three things happened:

1 The ALT breaker tripped

2 The Stratus battery is swollen

3 The Narco radio fried.

The alternator shouldn’t normally be capable of putting out enough current to trip the ALT breaker. The purpose of the breaker is to isolate a fault in the alternator or its wiring from the battery. 

A swollen Li-ion battery is indicative of over charging which could be due to over voltage.

Newer avionics will withstand a wide range of bus voltages - usually about 8 to 33 VDC. The old Narco is less tolerant of over voltage. 

Did you notice the bus voltage after you reset the ALT breaker? This might be a voltage regulator/alternator problem. Hard to tell without doing some troubleshooting. 

Skip

Bus voltage never got above about 14.2v.  

We've done all the testing we can think of and can't recreate the problem.  Is it possible the narco took a dump and caused the breaker to pop over a big transient draw? And then, I was flying on battery for who knows how long.  It could have been an hour.  The alt out light did not illuminate so I didn't know until I checked my battery voltage and saw it below 12v.  I have a plane power alternator, which I think is capable of 70 amps (have to check the model).  Could it have been putting out higher amps to recharge the battery and the narco thing was just the catalyst?

[PT20J]

15 minutes ago, ragedracer1977 said:

We've done all the testing we can think of and can't recreate the problem.  Is it possible the narco took a dump and caused the breaker to pop over a big transient draw? And then, I was flying on battery for who knows how long.  It could have been an hour.  The alt out light did not illuminate so I didn't know until I checked my battery voltage and saw it below 12v.  I have a plane power alternator, which I think is capable of 70 amps (have to check the model).  Could it have been putting out higher amps to recharge the battery and the narco thing was just the catalyst?

Another possibility is that these things are not all related. It will take between 110 and 150% of the breaker rating to trip it, and at those small overloads it will take several seconds to heat up enough to trip. The alternator shouldn’t be able to trip it unless the alternator has a short. Or ... if the breaker is bad. The Stratus problem could just be an old worn out battery and unrelated. Not sure how the Narco would fit in, but it’s old and if funny things were going on with the electrical system, it my have just given up.

I would start by figuring out why the ALT breaker is tripping because that should never happen unless there is a major fault. Likely the breaker is bad since the alternator and voltage regulator seem to be working after resetting it. I wouldn’t expect a fault that trips a 70A breaker to be transient.

Skip

[ragedracer1977]

21 minutes ago, PT20J said:

Another possibility is that these things are not all related. It will take between 110 and 150% of the breaker rating to trip it, and at those small overloads it will take several seconds to heat up enough to trip. The alternator shouldn’t be able to trip it unless the alternator has a short. Or ... if the breaker is bad. The Stratus problem could just be an old worn out battery and unrelated. Not sure how the Narco would fit in, but it’s old and if funny things were going on with the electrical system, it my have just given up.

I would start by figuring out why the ALT breaker is tripping because that should never happen unless there is a major fault. Likely the breaker is bad since the alternator and voltage regulator seem to be working after resetting it. I wouldn’t expect a fault that trips a 70A breaker to be transient.

Skip

It's a 50 amp breaker, if that matters