To twist, or not to twist?

[Steve Crewdog]

Got some single runs of 2 wires (OAT sensor,etc.) one manual says to twist and it will make a stronger run, other manual says DON'T twist, it will weaken the wires, instead tie them up. Only problem is tying them up makes for a bulky bundle of 2 wires.



Thoughts?

TIA

[Mich48041]

I would twist the wires. Twisted wires are less susceptible to noise.
Twisting wires will not weaken them unless they are twisted too tightly.

[PhatRV]

Originally Posted by Steve Crewdog

Got some single runs of 2 wires (OAT sensor,etc.) one manual says to twist and it will make a stronger run, other manual says DON'T twist, it will weaken the wires, instead tie them up. Only problem is tying them up makes for a bulky bundle of 2 wires.



Thoughts?

TIA

I am installing the wiring using Dynon avionics. The only non-shielded wires the Dynon insist on twisting are serial data wires for its network cable. The rest of the wires are straight. Dynon OAT wires are straight from the factory.

[emsvitil]

Use your safety wire pliers to do the twisting.............

[wirejock]

I always twist power and ground. Data wires are usually twisted but if not, I twist them.

[Paul K]

If you don’t want to twist, you can always sleeve. Bought two spools of the nylon snake skin sleeve and secured the ends with shrink wrap. Also bought heat resistant for FWF, it is identified by a white strand woven in. Makes for a very clean install!

[wjb]

Originally Posted by emsvitil

Use your safety wire pliers to do the twisting.............

Or your electric drill ... works great; but don't be too aggressive.

[Canadian_JOY]

Originally Posted by Steve Crewdog

Got some single runs of 2 wires (OAT sensor,etc.) one manual says to twist and it will make a stronger run, other manual says DON'T twist, it will weaken the wires, instead tie them up. Only problem is tying them up makes for a bulky bundle of 2 wires.



Thoughts?

TIA

It's been mentioned here in a previous post but I'll perhaps add a little emphasis... Twisting wires together has little to do with their physical strength and everything to do with their electrical properties. By twisting them together one achieves something referred to in the EMI/RFI world as "common mode rejection".

In simple terms, common mode rejection allows the two twisted wires to act together so that noise on the wires is effectively cancelled by the other wire. It's why our headset cables use Mil-C-27500 "twisted, shielded" wire. The wires twisted together form a strong tool to prevent electrical noise from manifesting as audible noise in the headset.

For signals like OAT, twisting the wires helps provide a more stable signal for interpretation by the digital hardware at the other end.

There's no sense in twisting so tight that one might damage the wires... It's surprising how little twist it takes to make an improvement in noise reduction. Even a couple of twists per inch is a big help.

[John Tierney]

Here is a video from Stein on how to twist, with caution.
https://www.youtube.com/watch?v=uTJhrTTl-EE

[Steve Crewdog]

Thanks everyone, for taking the time to educamate me. John, I was surprised how much the wires shortened when they were twisted.

[engage: Peter Falk voice]
One more question, if I may, sir, just one more question.]
[/revert: normal pilot/wannabe mechanic voice]

If twisting 2 wires going to the same destination is good, why not do that for all (i.e., wires going to various switches) before lacing them into one big bundle? Is it because of the bulk that would result from lacing a bunch of twisted 2 wires runs together?


TIA