"limited" EGT and CHT temperatures

[High_Flyer]

Hello Dynon,
My setup is full Skyview system with EMS 221, Aerosport IO-375-M1S engine.
I have made my 1st flight yesterday, and noticed that all 4 EGT were not reaching normal temperatures, all very low.
Today I tried to troubleshoot and found out that all 4 EGT do not go over 475°F, and all 4 CHT do not go over 375°F.
To see this I used a heat gun on the probes. I removed the EGT and the CHT probes and directed the
heat gun at them. Temperatures rises rapidly until reaching 475°F for the EGT / 375°F for the CHT and suddenly stops at those values, never go higher. My heat gun is set at the max temp of 1200°F
I do not understand why this is.
It seems that the probes are somewhow "limited" to these values...
This means no further flight until it is resolved because I will not know if my CHT are too high as the max value displayed is 375°F.
HELP PLEASE.
Atteched is a screenshot during yesterday's flight.

 

[High_Flyer]

And further to my 1st post a screenshot made just after landing.

 

[rvator51]

I would check all of the configuration settings. I suspect some are wrong. do you have your ranges for the sensors set properly?

 

[High_Flyer]

I would check all of the configuration settings.  I suspect some are wrong.  do you have your ranges for the sensors set properly?

The config settings can not be changed I think, and I checked the ranges and they are correct. And the ranges even if wrong wouldn't prevent the probes to sense more than 375/475 degrees...

 

[Dynon]

What are you using for the actual CHT and EGT probes? The CHTs must be type J thermocouples, and the EGTs type K. If you're using different sensors, they won't output the voltages SkyView is expecting to see.

 

[High_Flyer]

What are you using for the actual CHT and EGT probes? The CHTs must be type J thermocouples, and the EGTs type K. If you're using different sensors, they won't output the voltages SkyView is expecting to see.

All probes are Dynon, J and K thermocouples.
I ordered all standard Dynon equipment, EMS came with the probes and the EMS wire loom. All I did was shorten the cables from the EMS to the probes (NOT the cables of the probes) as the manual says is allowed.

I tested one EGT probe with a multimeter:
O ohms,
Close to 0 milivolts at ambiant temperature,
22,3 Milivolts with the probe inside the mouth of a heat gun at 1220°F.

The nubers on the labels of the probes are: 100405-000 for the EGT, and 100404-000 for the CHT.
The EMS is SV-EMS-220 (see screenshot).

 

[High_Flyer]

Screenshot of the sensor input mapping:

 

[High_Flyer]

Screenshot of the sensor debug data:
Please note that at the moment of this screenshot the #2 EGT probe was not installed as I was testing it.

 

[dynonsupport]

Can you please send a screen shot of the debug screen scrolled down a bit? There's a section with a bunch of elements like "ColdJ" and "vref+" that would be helpful.

 

[High_Flyer]

Can you please send a screen shot of the debug screen scrolled down a bit? There's a section with a bunch of elements like "ColdJ" and "vref+" that would be helpful.

Following are ALL the debug pages:
1

 

[High_Flyer]

2

 

[High_Flyer]

3

 

[High_Flyer]

4

 

[High_Flyer]

5

 

[High_Flyer]

6

 

[High_Flyer]

7

 

[High_Flyer]

8

 

[High_Flyer]

9

 

[High_Flyer]

What I've done troubleshooting so far:
- Checked proper probes model installed: OK
- Checked proper EMS installed (EMS 220): OK
- Checked continuity of the wires to the proper EMS pin : OK
- Checked "polarity" of the wires: OK
- Checked Gounds: OK
- Added a ground wire direct from EMS to engine block
- Verified Debug page parameters as told by Dynon support:
     Volt Ref around 5V: OK
     TC Offest around 0.4V : OK
     Clod J around room temp : OK

Ordered other EMS from Finesse max (France Dynon rep), should arrive tomorrow.
If it's not the EMS that's faulty then I really don't know what else to do...

 

[dynonsupport]

Alain,
Given the reasonable values from your sensor debug page, it's not likely that the EMS has failed, but it will be interesting to see if that does fix it.

Your limits of CHT and EGT say that the system can no longer read above 20mV. 375F on a J type is 20mV and 475F on a K type is 20mV. So there is a hint there.

Can you please try something else? Heat one of the probes with your heat gun again, but looking at the sensor debug page for that sensor instead of the main screen. What does the line for that sensor show when you do this?

If it is limiting on that page, please un-plug the D37 connector and try again to see if anything on that connector is causing the issue.

Also, have you checked that you have no inputs connected to any of the unused thermocouple inputs? If you were to hook a 5V or 12V signal to one of the unused inputs it could cause this issue.

We'll figure it out!