435C EGT??????

Re: 435C EGT??????

by Rhett Mitchell » 10 years ago

Rhett Mitchell

8 99 0

My wrap bumped temps about 30 to 50 degrees C. from uncovered pipes.

Re: 435C EGT??????

by Roger Lee » 10 years ago

Roger Lee

131 5.38k 5.44k

The wraps I have done didn't seem to affect the EGT temps at all. The wrap shouldn't affect the burn of the fuel or it fuel temp as it exits the exhaust port because the probe is so close.
50c would be a lot.

---

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

Re: 435C EGT??????

by Ian Rees » 10 years ago

Ian Rees

6 42 0

Hi Dave,
I have found the following root cause failure mode for one EGT sender which read incorrectly.
Test yours to see if it also failed in the same way. The test is simple and easy to do.

The EGT probe is a thermocouple with the probe wire isolated from the metal fixing. The isolation from the metal fixing is to avoid a ground return or short to the airframe which will cause wrong temperature readings.

Disconnect the 2 wires from the EGT gauge or measurement unit. Test the continuity from each wire to the airframe ground. The circuit should be open. An EGT can have a damaged outer sheath where it exits the metal fixing which can cause a high impedance to the airframe. The damage can be due to mechanical abuse of the cable as it exits the metal fixing due to flexing. Often caused by poor installation, particularly on the M8 screw in fittings. This is because the cable must rotate as it is screwed into the exhaust.

Hope this helps.

Re: 435C EGT??????

by Dave Rigotti » 10 years ago

Dave Rigotti

11 27 0

Ian,
No shorts between each lead and outer sheath. Probe is simply defective from vendor. Being replaced at no cost.
I'll post results when rec'd.
Thank You

Re: 435C EGT??????

by Liav Chen » 10 years ago

Liav Chen

1 2 0

Hi Dave

If I understand your test bench figure correctly, the EGT sensors you have compared are not of the same type. Is the wrong reading received using a thermocouple type sensor? If that is the case, you should verify whether your monitoring device is either adequate to this sensor type or it may need to be calibrated.

Ron