CHT/EGT wiring

[bob888]

Do all the probe wires need to be same length or can some be shorter/longer than others, i.e. #5 shorter than #1. This may seem like a silly question but it is hard to make a short wire longer...

 

[Jesse]

You can trim them if you need to. I have never had trouble with the standard harnesses being too short. Sometimes I keep them standard length and sometimes I trim them as necessary.

 

[Walt]

If they are within a few feet of each other the difference in temp reading would be negligible.

From the Omega website:

What is the maximum length of thermocouple wire?

There are many factors that can impact the usable length of a thermocouple. As a guideline, under 100 feet with 20 AWG or thicker wire in an area free of electromagnetic interference usually is fine.

 

[RV3bpilot]

Sensor wires

Make sure the sensor wires are shielded..

 

[Auburntsts]

Make sure the sensor wires are shielded..

Why? I don't believe standard thermocouple wire is shielded and I've had zero issues with either my CHTs or EGTs. Also for my Garmin system, shielded wire is not called for in the installation manual.

 

[Jesse]

I've never seen shielded thermocouple wire. The sensors usually have a wire braiding over their wires, but that seems to be more for protection than electrical interference. From there to the screen I've never seen shielding.

 

[Walt]

There certainly are thermocouple wires available with a metal over-braid (shielded) and it was standard from many of the better egt/cht instruments suppliers in the past, but seems not as much anymore. Thermocouple wires are susceptible to magnetic interference from power wires, motors, generators etc. so it's good practice to separate them from these items and preferably should not be run in bundles with power wires.