Wiring between main and starter contactor...

[Michael Burbidge]

I'm using a short length of battery type cable made by B&C to connect my main contactor to the starter contactor. Both contactors are from B&C. The orientation of the terminal bolts on the contactors does not make for using copper bar easily.

I've enclosed a picture. My question is, do you the think the radius of the bend will put too much stress on this wire? If so, what would you suggest?

Thanks,
Michael-

[mannanj]

Looks ok to me from here. If you're worried about it, make a new one with welding cable. It is super flexible and should make that radius easily.

[Frank Smidler]

You can shorten the wire and bend the terminal connection over 90 degrees to make a neater installation. That being said, it looks OK as it is as long as it will not rub against the battery box.

[Captain_John]

...or do it like i did with a twist in the copper bar.



. CJ

[TX7A]

You probably knew this, but when you crimp the terminals on, make sure they are "clocked" so you don't have to twist the cable when you put the ends on the studs. Don't want to introduce any stress.

[idleup]

CJ,

Where did you get that copper bar you used to interconnect the contactors and what size/thickness is it? Also, how did you do the black on there, it looks like rubber. Thanks

Matt

Originally Posted by Captain_John

...or do it like i did with a twist in the copper bar.



. CJ

[UnPossible]

Vans sells copper bus bars. http://vansaircraft.com/cgi-bin/stor...oduct=buss-bar

To me it looks like the black is just heat shrink tubing.

Hope this helps,
Jason

[Mel]

Originally Posted by idleup

CJ,
Also, how did you do the black on there, it looks like rubber. Thanks
Matt

Looks like heat-shrink tubing to me.

p.s. Obviously Jason types faster than I do. My recent eye surgery has slowed my keyboard!

[az_gila]

Originally Posted by UnPossible

Vans sells copper bus bars. http://vansaircraft.com/cgi-bin/stor...oduct=buss-bar

.......

Hope this helps,
Jason

If you want to equal #2 gauge wire, you should use two strips of Vans bus bar in parallel.

One strip is only about 55% the copper cross-section area of a #2 wire.

[DanH]

Originally Posted by Michael Burbidge

My question is, do you the think the radius of the bend will put too much stress on this wire?

No. The minimum radius for a wire is roughly the same as the minimum bend radius for sheet or bar material with thickness equal to the individual wire strand diameter. Put another way, the concern is cracking of the individual strands, just like cracking an aluminum sheet part by using a bend radius that is too small.

You're not anywhere near the plastic region for those wire strands.

Concern about "preload stress" is baseless. Consider your torque-to-length Lycoming connecting rod bolts, or the stress on your landing gear right now, sitting quietly in the hangar.