Failed klixon breaker l

[RobertGary1]

Yesterday my edm 700 I’ve had for about 15 years went dead on approach. A call to my avionics guy suggested wiggling the breaker.  Sure enough even pushing the breaker in (that was already in) caused the monitor to go on and off. He suggested shutting down power snd just pulling the breaker over and over to clean the contacts.  That worked. Seems good now. He said this failure is rare. 
 Going jnto annual jn a few weeks. Should I go ahead and just plan to replace it to avoid future issues or do you think the fix of exercising it may hold?

[romeotango]

Should be pretty cheap to replace for peace of mind.

[Ragsf15e]

Cheap and easy to replace if you can reach the wiring easily.

[AerostarDriver]

I just discovered my alternator breaker was split in half. If I pressed on the right side panel would cause everything to shut off. It was about 50 bucks to replace.

[Ragsf15e]

Spruce has all the klixon varieties.  Depending on amperage, $20-$75.  Most of the small breakers are about $25.

[Skates97]

1 minute ago, AerostarDriver said:

I just discovered my alternator breaker was split in half. If I pressed on the right side panel would cause everything to shut off. It was about 50 bucks to replace.

I would at least have the breaker pulled to look at it. When we were working on the panel we found a crack in the case of one and another that when it was unscrewed from the buss bar it came apart. The only think holding it together was that it was mounted in the panel with the buss bar holding it together.

[Marauder]

In my 30 years of ownership, I have seen at least a half dozen fail. None like Richard's. What I have seen is they trip sooner than their rated amperage. I have been "exercising" for the past decade and they seem to fail less often.

If I recall correctly, the Klixon style breaker is used in some aircraft as the on/off switch.

[RobertGary1]

33 minutes ago, Marauder said:

In my 30 years of ownership, I have seen at least a half dozen fail. None like Richard's. What I have seen is they trip sooner than their rated amperage. I have been "exercising" for the past decade and they seem to fail less often.

If I recall correctly, the Klixon style breaker is used in some aircraft as the on/off switch.

It is my autopilot on/off switch. I believe what happened is I pulled the autopilot breaker (the normal procedure to disconnect in the manual) and must have slightly touched the EDM breaker. Just wiggling the EDM breaker reproduces the problem.

I know there are a few different model numbers of the breakers so I'll try to get in there and see if I can read the number.

 

So in general is it advisable to exercise all the breakers on some schedule? To prevent contact corrosion? 

-Robert

[bradp]

I’ve had a couple fail.  Usually it’s been the spring no longer holds. 

[Marauder]

2 hours ago, RobertGary1 said:

It is my autopilot on/off switch. I believe what happened is I pulled the autopilot breaker (the normal procedure to disconnect in the manual) and must have slightly touched the EDM breaker. Just wiggling the EDM breaker reproduces the problem.

I know there are a few different model numbers of the breakers so I'll try to get in there and see if I can read the number.

 

So in general is it advisable to exercise all the breakers on some schedule? To prevent contact corrosion? 

-Robert

I think our Mooneys are using the 7277 series breakers. Your breaker rating will be stamped on it.

https://www.aircraftspruce.com/catalog/elpages/klixon7277.php?clickkey=40017

[Skates97]

And they come in two ways, 7277-2-x and 7277-5-x. The x is the rating, the -2 and -5 are the short and long. You most likely have the -2 and you want to replace with the same or they will not be even and makes it weird when checking that they are all in. 

[A64Pilot]

It was I believe 1983, I had just completed my first phase inspection of an OH-58 helicopter. Phase is similar to an annual. 

These were Vietnam era helicopters, so pretty old. The test pilot got in after the pre flight of course and started pulling circuit breakers, there was one or two that couldn’t be pulled.

There is no inspection to check if they can be pulled, it’s not in the book, but from then on when an aircraft got inducted into phase, one of the first things I did was to pull all of the breakers.

Assumption is, given enough time they may corrode in place, maybe in an overload they will still trip. but if you can’t pull it, it’s bad.

‘So, ever since then whenever I annual, I pull all of the breakers, it’s one reason I dislike the flush breakers Cessna and others use

 

Edited April 14, 2021 by A64Pilot

[N201MKTurbo]

26 minutes ago, A64Pilot said:

It was I believe 1983, I had just completed my first phase inspection of an OH-58 helicopter. Phase is similar to an annual. 

These were Vietnam era helicopters, so pretty old. The test pilot got in after the pre flight of course and started pulling circuit breakers, there was one or two that couldn’t be pulled.

There is no inspection to check if they can be pulled, it’s not in the book, but from then on when an aircraft got inducted into phase, one of the first things I did was to pull all of the breakers.

Assumption is, given enough time they may corrode in place, maybe in an overload they will still trip. but if you can’t pull it, it’s bad.

‘So, ever since then whenever I annual, I pull all of the breakers, it’s one reason I dislike the flush breakers Cessna and others use

 

You should have my fridg magnet.

[A64Pilot]

I enlisted in 1982 as a 67V, OH-58 repairer, took me almost four years and three attempts to get picked up for flight school, a few towards the end of flight school got to select our aircraft, I picked the AH-64.

‘I Retired in 2002, since then somehow or another, I’ve lost most of my trinkets, that was actually another life it seems

[N201MKTurbo]

10 minutes ago, A64Pilot said:

I enlisted in 1982 as a 67V, OH-58 repairer, took me almost four years and three attempts to get picked up for flight school, a few towards the end of flight school got to select our aircraft, I picked the AH-64.

‘I Retired in 2002, since then somehow or another, I’ve lost most of my trinkets, that was actually another life it seems

My son worked for Boeing in Mesa for a couple of years. I went to a few of their open houses.

[A64Pilot]

Been to Mesa picking up aircraft etc many times.

‘Did you go to the museum on the other side of the airfield? They had an HE-111 when I did.

[EricJ]

4 minutes ago, A64Pilot said:

Been to Mesa picking up aircraft etc many times.

‘Did you go to the museum on the other side of the airfield? They had an HE-111 when I did.

I used to see the He-111 fly over my house once in a while, but it crashed many years ago, killing the crew.

 

[Ragsf15e]

10 hours ago, Skates97 said:

I would at least have the breaker pulled to look at it. When we were working on the panel we found a crack in the case of one and another that when it was unscrewed from the buss bar it came apart. The only think holding it together was that it was mounted in the panel with the buss bar holding it together.

I broke the 50amp aux bus breaker while trying to remove it.  The 50 amp ones get expensive.  I was just trying to clean and secure all the wiring.  I guess what I’m saying is the CBs are pretty delicate and the wiring is pulling from several directions.  It’s tough to maneuver everything around without stressing some of the parts.

[carusoam]

Swapping out a single CB that is in the middle of a row... the bus bar on the back comes off...

Really good to have the access panels in front of the windshield that day...  

Best regards,

-a-

 

Wait a minute...  this HE-111?  https://en.wikipedia.org/wiki/Heinkel_He_111
 

[EricJ]

7 minutes ago, carusoam said:

Wait a minute...  this HE-111?  https://en.wikipedia.org/wiki/Heinkel_He_111
 

Yes.   The AZ CAF was operating it and it crashed in 2003.

https://aviation-safety.net/wikibase/45157

https://www.treasurebunker.com/forums/index.php?/topic/2328-the-last-flying-heinkel-he-111/

[A64Pilot]

11 hours ago, carusoam said:

Swapping out a single CB that is in the middle of a row... the bus bar on the back comes off...

Really good to have the access panels in front of the windshield that day...  

Best regards,

-a-

 

Wait a minute...  this HE-111?  https://en.wikipedia.org/wiki/Heinkel_He_111
 

Yes that one. I didn’t even know of it’s existence and “found” it outside on the ramp at the museum, they also had a B-17 with horribly damaged leading edges. I asked about the damage and was told it was a fire bomber in the past, I’m not sure why fire bombing would cause so much damage?

Anyway maybe because I was in a military flight suit, I got to go inside and climb around in the HE-111

They had a lot of neat stuff at the Museum, and what was really interesting was it wasn’t behind ropes and glass cases etc, I got a good look at a Gnome rotary engine for example and I’d never seen one before. It was really interesting, it had extremely weak valve springs for instance, I believe they were for starting only. the rocker arms had counter weights on them, I believe these weights provided the closing force for the valves, the faster it spun, the greater the force if I’m right, which is pretty darn smart, a lot of energy is lost through valve springs on a conventional engine, they knew that and came up with a better way, over 100 years ago.

It’s astonishing how much was known way back in the day, My Wife’s Grandfather for instance was an aircraft mechanic I assume right after WWI, he got his license by a correspondence course, I have most of those books, the attached photo is from one of them where the average aircraft is shown to illustrate parts. It’s a Curtiss JN-4 Jenny.

I never met him, he was gone before I came around, but his legacy if you will is still around. He later worked at Turner Air Force base in Albany Ga., and built a “drop tank” luggage carrier for some kind of aircraft there, the Col liked it and on one trip to Japan in a B-52 bought him a set of China as a gift, so now my Daughter’s set of China was smuggled into the US in the belly of a Nuclear bomber, how many can say that?

Somewhere I have a Nose gland nut wrench for a YP-59 too, what surprises me about that is it’s a cast manufactured part or possibly forged, for a experimental airplane.

On edit, what these books are particularly good at is wood repair as of course most aircraft were constructed from wood, it tells you how to make your own adhesives and all kinds of info that’s over my head actually as I have no experience with wood.

‘But anyway in school now we are told things like don’t use a non castellated nut on a drilled bolt, but not told why, his old books explained it was due to the drilled cavity being trapped under the nut could lead to corrosion and eventual failure of the bolt, they knew that over 100 years ago, and went to the trouble of explaining it, now we are just told not to.

 

Edited April 15, 2021 by A64Pilot