Mep 802a bogs down when a/c circuit interrupt

[Renojxd]

Check these wires behind the fuel/water separator. They connect the circuit interrupter contactor and the output lugs. Despite them being routed through a P-clamp, they can still rub on the edge of the sheet metal, which is compounded by how much an 802 shakes when running. Here is an example of an 802a I refurbished where one of the wires had rubbed through and was arcing on the chassis. (red circle)
View attachment 938178

Here is an image from someone else's unit with the top off. You can see where the wires exit the contactor and head down to the output lugs. (top). Plenty of places to rub against the sheet metal.

Do you know the specs of the output conductors feeding the lugs. Or a suitable splice to make repairs?

 

[Light in the Dark]

Do you know the specs of the output conductors feeding the lugs. Or a suitable splice to make repairs?

I wouldn't splice those lines. I would determine the length, gauge, and termination size, and have new ones made up complete (or sourced used from a parts machine if thats preference). Not the spot I would personally want a 'fix' to fail.

 

[2Pbfeet]

Right, we called it Safety wire. Being into racing I did a lot of safety wiring tying. I was taught how to be efficient by an aviation mechanic.

Any tips for us amateurs?

 

[kloppk]

Cable info from the -24 TM for cables from Contact to the lugs

 

[Guyfang]

Any tips for us amateurs?

1. Do you have the proper wire plyers?
2. Practice!!!!!!!!!!!!!!!!!!!!!!!!
3. Talk to a pro. Go to an aviation shop/hanger. Find an old Rotor Head mechanic. Or someone who has worked on Turbines.
4. Practice!!!!!!!!!!!!!!!!!!!!!!!!
5. Get several different diameter wires.

 

[2Pbfeet]

1. Do you have the proper wire plyers?
2. Practice!!!!!!!!!!!!!!!!!!!!!!!!
3. Talk to a pro. Go to an aviation shop/hanger. Find an old Rotor Head mechanic. Or someone who has worked on Turbines.
4. Practice!!!!!!!!!!!!!!!!!!!!!!!!
5. Get several different diameter wires.

Yes to #1, and #2, though for sure not enough practice!
#3: I thought that I did ask a pro. And yes, I probably should just hang out at the local aviation watering hole.
and, yes, I have several different diameter wires.

It probably says something that I find the results aesthetically pleasing...

All the best,

2Pbfeet

 

[rickf]

Yes to all of the above, and you have the advantage we did not have. I am SURE you could find a video of safety wire installation on You Tube.

 

[2Pbfeet]

Yes to all of the above, and you have the advantage we did not have. I am SURE you could find a video of safety wire installation on You Tube.

I found several! Many with conflicting advice on what the FAA supposedly requires, which is fortunately not an issue for me, but lots of good suggestions on technique. Thanks.

All the best,

2Pbfeet

 

[rickf]

OK, now I am going to have to drag out my tool and start practicing again. I have no idea why since I don't have anything with the required hols in the bolt/nuts. You damn guys and your ideas!

 

[Guyfang]

Truly, its something you have to watch, and ask questions about, WHILE its happening before your eyes. I once, a long time ago, had to safety wire a plate to a Hawk launcher, with 22 bolts. When I was done, it was functional. But looked like crap. SSG Jack Young laughed at me and my work. Spit some chew on the ground and told me to cut it all off. Then try again. After 3 tries, he "guided" me through the whole thing, with an every now and then jab to the ribs, It still looked like crap. But MUCH better. Then he cut all the wires and walked off laughing. It was hard to tell if he was laughing or saying bad things about me. His store bought choppers were still in his shirt pocket.

 

[rickf]

The biggest trick to the whole thing is making sure the tension wire comes off the top side of the bolt on the left down to the bottom side of the bolt on the right. Sounds easy but this is what got me every time.

 

[2Pbfeet]

The biggest trick to the whole thing is making sure the tension wire comes off the top side of the bolt on the left down to the bottom side of the bolt on the right. Sounds easy but this is what got me every time.

I think of it as how the bolt could loosen in "righty righty, lefty loosely" and do the wire tension from there, but it is the same end result.

One of the videos I looked at from a turbine tech ("Jet Tech") wrapped the "backside" wire around the bolt and under the primary wire and then used a jerk to set the wire tension and bend that seemed like a quick way to get the slack out and set yourself up for the correct wire twist, but what do I know?

All the best,

2Pbfeet

 

[rickf]

Don't forget left hand threads, There's a monkey wrench for you. LOL Does your head hurt yet?
We might want to get back to helping out the OP.