S8 Thermocouple Wiring

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Jman
Posts: 9
Joined: Mon Oct 26, 2015 2:47 pm

S8 Thermocouple Wiring

Post by Jman »

Hello again,

I posted earlier regarding thermocouple wiring but I am still having issues. I have two K-type thermocouples wired directly into the S8 through the four specified pins. The wiring on both the thermocouple and ECU sides is correct, but the voltage reading is constant regardless of temperature. Both sensors are specified as K-types in SCal so I can't figure out what the issue is. There isn't a separate voltage curve required for K-types correct?

Is there any additional setup for thermomcouples in SCal that I could be missing? Any help would be appreciated.
Slowie
Posts: 123
Joined: Thu Jan 17, 2013 7:30 am

Re: S8 Thermocouple Wiring

Post by Slowie »

From your post, it seems you have a flat linearization for the K-Type sensors, correct? If not, please make sure to set the EGT sensor linearizations to "0" throughout.
Jman
Posts: 9
Joined: Mon Oct 26, 2015 2:47 pm

Re: S8 Thermocouple Wiring

Post by Jman »

Thanks for your input. Yes the linearizations are set to 0V throughout.
TimH
JT Innovations
Posts: 718
Joined: Wed Sep 01, 2010 3:51 pm

Re: S8 Thermocouple Wiring

Post by TimH »

I've never looked at the voltage reading for an EGT in SCal; if you pull up a gauge for the actual EGT readings, do they look correct?
Slowie
Posts: 123
Joined: Thu Jan 17, 2013 7:30 am

Re: S8 Thermocouple Wiring

Post by Slowie »

And both sensors are defined in I/O Configuration->Pin Assignments->Exhaust gas temp as per the pic? Sorry if that sounds very basic, but sadly I have no other bright ideas.
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S8 EGT.png
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RICE RACING
Posts: 448
Joined: Mon Feb 24, 2014 1:08 am

Re: S8 Thermocouple Wiring

Post by RICE RACING »

Jman wrote:Hello again,

I posted earlier regarding thermocouple wiring but I am still having issues. I have two K-type thermocouples wired directly into the S8 through the four specified pins. The wiring on both the thermocouple and ECU sides is correct, but the voltage reading is constant regardless of temperature. Both sensors are specified as K-types in SCal so I can't figure out what the issue is. There isn't a separate voltage curve required for K-types correct?

Is there any additional setup for thermomcouples in SCal that I could be missing? Any help would be appreciated.
The only time I have seen this is when a customer had the same issue (constant reading on one TC) he assured me the wiring was correct as it was done by a FSAE co ordinator & mech eng teacher of all people, upon checking all items I found that the TC (-) was wired into the wrong pin location in the 88way connector.
Please confirm that its wired as per below:
Image

Once this was fixed by me it worked as intended.

The linearization table or voltage curve is not used when you select K-Type as the input.
To test the TC probes themselves unplug at the mini K connector and put a multi meter across the pins and heat up the probe tips and see that the voltage changes just to be sure edit: also worth mentioning, I have come across people who did not use the right TC extension wire (F88 side wiring) > general notes here http://au.rs-online.com/web/generalDisp ... uple-cable
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