EGT/CHT with same ground and cables

[mcr01passion]

Converting a 4 EGT/4 CHT westach indicator on EMS, I have only one ground cable coming from the engine.
On the former installation, with a Westach rotator switch, it was working fine.

But When I split these grounds on different pins of DB25 on EMS... This doesn't work :-(

I have to precise that the former builder/constructor had installed standard electrical cables, and didn't used dedicated cables for thermocouples...

Help again...

 

[dynonsupport]

It won't work that way. Thermocouples work by generating a differential voltage between the pair of thermocouple specific wires. In a switched configuration, one side of that circuit is always be the one side of the circuit for the connected probe, but, it's only connected to one probe at a time. If you're monitoring each temperature at the the same time like we do, each thermocouple needs a dedicated pair of thermocouple wires (and the type of wire matters too). That isn't a "ground', in other words, that can be split. Each probe needs its own dedicated pair of wires of the correct thermocouple type.

 

[mcr01passion]

Ok, I will try that.

 

[mcr01passion]

Re: EGT/CHT with same ground and cables [RESOLVED]

For information, we followed Dynon advice and it works perfectly now