Labelling high temperature wiring

[Jaba-who]

On 14/12/2020 at 11:45 AM, Yenn said:

jim Weir of Kitplanes described using the resistor code colours for marking with shrink wrap. He had a system that had for example all engine wires starting with 1 and all instrument wires with 2 and then a further three numbers. The start end also had to be marked.

Really unless you have a very complex engine there is not much wiring that is not apparent in its purpose firewall forward.Starter cables are heavy, alternator cables a bit less so, CHT and EGT are lightweight and visibly traceable. Wires going to relays can usually be seen easily.

Not true anymore I’m afraid. 
add 1 skyview or any of the many EFIS/EMS now available at cheapish  prices to your aircraft and you can have 20 - 30 wires going through your firewall.

 

As soon as you loom up wires (especially the EGT and CHT wires or any wires that are similar size) you lose identity of every one of them. One breaks and you have to pull the entire loom apart to identify just one wire and which cylinder etc it’s off. 
Been there done that! 

The  colour code system seems a lot of trouble  - write ( or laser print in English on a bit of paper under clear heat shrink.)

Same fire risk. 

 

[Blueadventures]

11 hours ago, Jaba-who said:

Seems the original quest was for something that was fire/flame resistant. 
None of these ( except maybe  the use of coloured Tefzel - which is  available. ) But doesn’t really  provide a foolproof easy labelling system ( since you need a copy of the code with you. Inevitably  you have a problem at a far off strip and you end up without your code book or you end up in a loom with multiple wires of the same colour etc ) 

Frankly  I don’t know of one either but I decided to take the risk and just label things in English properly -  use short bits of clear heat shrink with a laser printer printed (size 8 font) paper strip under it. The short bit of heat shrink might be flammable but in the grand scheme of things the heat shrink bits are about a couple of cm long so the risk is small but the gain in labelling immense. 
Have completely rewired my Jabiru multiple times and worked on parts of the wiring etc many times. And when it comes to working on it easily you really need every wire labelled at both ends with a text label. No need then for codes and records. 
 

If someone produced a heat resistant heat shrink equivalent I’d use it in a flash  but so far not found anything that works as well as a printed label under clear heat shrink. 

That’s what I do English shorthand and attach at both ends of circuit if a long run. Rather than printer, I have a piece of paper and sissors close by and sharp pencil.  All wiring is tefzel and colours are used as well. My wiring diagram is in A3 size and colour.  I modified the savannah one on the net and whited out bits and reprinted then added my detail and keep a reduced A4 copy on board.  Save a lot of time trouble shooting when and if you have to.

 

when ever I assist some one I lable the wire runs as their identified and remove any disused wires.

Edited December 15, 2020 by Blueadventures

[RFguy]

thanks for everyone's input

 

Jaba, that is precisely it. . tracing stuff there needs to be no guessing, nor assumptions  and not too much time used, chasing wires in wire looms  is trouble.

 

especially, ignition stuff, oil senders, fuel senders, magneto controls, CHTs EGTs solenoids, ... spark plugs (12 leads) is just the beginning. 

 

(in the old days (me with vehicle engines)) nice to be able to pop off the  heads with gay abandon, quick valve job, and putting it back together with numbers on stuff.  Numbers and letters and doco on stuff I beleive is mandatory. But that's the way I guess we wire up broadcast radio transmitters in  a different industry.

 

There is some quite good hi temp temp shrink from TE.  like HT-200. (attached) 

https://www.te.com/global-en/products/heat-shrink-tubing/ht-200-heat-shrinkable-tubing.html?tab=pgp-story

 

 

 

ENG_SS_TEC-108-120028_A.pdf

[skippydiesel]

Just received a humongous Sport Pilot magazine - page 98 "What's Hot" DYMO RHINO 4200 INDUSTRIAL LABEL MAKER, $134 from Office Works. Sounds like it just might be what we have all been looking for.

[M61A1]

1 hour ago, skippydiesel said:

Just received a humongous Sport Pilot magazine - page 98 "What's Hot" DYMO RHINO 4200 INDUSTRIAL LABEL MAKER, $134 from Office Works. Sounds like it just might be what we have all been looking for.

You may find that the labels made by those machines just revert to their base colour when exposed to  (not very) elevated temperatures. I bought a nice one like that and it made great switch labels for the cockpit, but my spark plug lead labels in the cowl  turned completely black very quickly.

[RFguy]

"thermal printer".

[skippydiesel]

1 hour ago, M61A1 said:

You may find that the labels made by those machines just revert to their base colour when exposed to  (not very) elevated temperatures. I bought a nice one like that and it made great switch labels for the cockpit, but my spark plug lead labels in the cowl  turned completely black very quickly.

At the risk of being boring I repeat:

 

Not sure why you want to label engine compartment cables - they are mostly short runs, that terminate at a point that makes their application obvious.

 

Behind the instrument panel - different story all -together.

[Jaba-who]

On 16/12/2020 at 7:53 PM, skippydiesel said:

At the risk of being boring I repeat:

 

Not sure why you want to label engine compartment cables - they are mostly short runs, that terminate at a point that makes their application obvious.

 

Behind the instrument panel - different story all -together.

Without being boring same answer as before. 

They are  not always short, ( but short doesn’t mean they can’t be convoluted and impossible to follow), they are loomed, they are not always obvious, and there are lots and lots of them. Your statement might be reasonable if it was an accurate description but it is just not correct.  

 

If one wire disconnects OK it won't be an issue but it is not  helpful especially when multiple wires are disconnected. 

 

Even following a spark plug lead that came off the distributor can be a one second job with a label on it and a half hour job with out it. 

 

Eg: Ok -let’s make that 2 leads pop off or are taken off the distributor

To correctly reconnect them   (:in a jabiru especially) will require removal of the ram air ducts so you can follow the lead all the way to the cylinder, [that may require removal of the bottom cowl in some aircraft ( I have seen a couple where the removal of the front cap screw holding the ram ducts needed the bottom cowl removed,] cutting all the zip ties  of all the wires in the loom to follow and ensure you have the right lead, then check again, then run the engine and if it there’s a problem recheck it all etc etc. 

 

or

 

simply pick up the dislocated ends, read the label and reinsert it onto the distributer, followed by repeat for the second lead. 

 

Same applies to 6 CHT leads, 6 EGTs, an oil pressure sender wire, a back up CHT sender wire, the multiple wires to the regulator, solenoids, master relay, Amp high and low shunt sender, fuel flow sensor wires, Radio wires that go directly to the battery, hard wired strobe light wires.

To say they are short and obvious is not a factual representation of the state of engine bay in many aircraft these days. 

 

 

 

 

Edited December 22, 2020 by Jaba-who

[Jaba-who]

On 16/12/2020 at 6:00 PM, M61A1 said:

You may find that the labels made by those machines just revert to their base colour when exposed to  (not very) elevated temperatures. I bought a nice one like that and it made great switch labels for the cockpit, but my spark plug lead labels in the cowl  turned completely black very quickly.

That’s very useful to know. 

I had a look at the webpage of the device after the first posting above and was thinking that despite the cost  it might still be worthwhile if it makes making the labels quicker. But sounds like back to my old method. 

[Jaba-who]

On 15/12/2020 at 8:48 AM, old man emu said:

Ahh! Those Russians!

I’m assuming you are referring to the urban legend about the US space program spending millions to develop a pen that would work in zero gravity but the russians just used a pencil. 

 

Just as a bit of interesting side info:

I heard that it’s apocryphal and that no one, not even the Russians, used a pencil because pencils give off microscopic fine powder of graphite into the air when used.  In zero gravity the graphite powder  floats about in the “air” in the capsule environment and shorts out electrical equipment. 

 

Can’t vouch for the veracity of this but gives an interesting twist on the urban legend.  

 

[old man emu]

To label or not to label? That is the question.

[onetrack]

The best piece of equipment I have ever worked on, as regards electrical repairs, was the old International ACCO ("Butterbox") trucks.

Every wire was numbered at regular short intervals, with the numbering built into the wire insulation. It made electrical repair work a breeze.

[skippydiesel]

3 hours ago, Jaba-who said:

Without being boring same answer as before. 

They are  not always short, ( but short doesn’t mean they can’t be convoluted and impossible to follow), they are loomed, they are not always obvious, and there are lots and lots of them. Your statement might be reasonable if it was an accurate description but it is just not correct.  

 

If one wire disconnects OK it won't be an issue but it is not  helpful especially when multiple wires are disconnected. 

 

Even following a spark plug lead that came off the distributor can be a one second job with a label on it and a half hour job with out it. 

 

Eg: Ok -let’s make that 2 leads pop off or are taken off the distributor

To correctly reconnect them   (:in a jabiru especially) will require removal of the ram air ducts so you can follow the lead all the way to the cylinder, [that may require removal of the bottom cowl in some aircraft ( I have seen a couple where the removal of the front cap screw holding the ram ducts needed the bottom cowl removed,] cutting all the zip ties  of all the wires in the loom to follow and ensure you have the right lead, then check again, then run the engine and if it there’s a problem recheck it all etc etc. 

 

or

 

simply pick up the dislocated ends, read the label and reinsert it onto the distributer, followed by repeat for the second lead. 

 

Same applies to 6 CHT leads, 6 EGTs, an oil pressure sender wire, a back up CHT sender wire, the multiple wires to the regulator, solenoids, master relay, Amp high and low shunt sender, fuel flow sensor wires, Radio wires that go directly to the battery, hard wired strobe light wires.

To say they are short and obvious is not a factual representation of the state of engine bay in many aircraft these days. 

 

 

 

 

Hi Jaba - like you appear to be doing, I can only speak from my own experience: 

 

The only time I have a need to label engine compartment wiring , is when I am removing/replacing the engine and even then much of the wiring is self explanatory (ie can only fit in one position). The labeling I use at this time need not be anything special, as it will be removed immediately  after first successful engine start up/system checks.

 

Behind the instrument panel and a few other places within the airframe; very different story, I have everything labeled, at point of origin and termination  & a few, in between.