Thermocouple shorting when extruder is on

[heoconnor]

Hi,

I'm trying to set up a titan aqua extruder to a Duet 2 ethernet board. I'm using a high temp heat cartridge, a thermocouple daughterboard and a type K thermocouple - all seem to be working.

When trying to test the motor in the extruder, it briefly moves but causes an error to the temperature sensor:

Error: Temperature reading fault on heater 1: sensor short to other wiring

I can't see any reason it is physically shorting.

Could this be an error in the way I have configured?

[dc42]

The thermocouple junction must be electrically insulated from the casing of the thermocouple. The E3D thermocouple cartridges are insulated in this way, but many other types are not. What thermocouple are you using?

[heoconnor]

Thanks for the speedy response!

It is from E3D, a type K thermocouple cartridge...

[A Former User]

Suppose it could be faulty, try measuring continuity between the leads and the case?

[heoconnor]

@bearer it doesn't fault when heating it (without extruder motor) that's what is so weird!

[A Former User]

Hmm, noise?

[dc42]

@heoconnor said in Thermocouple shorting when extruder is on:

@bearer it doesn't fault when heating it (without extruder motor) that's what is so weird!

Yes, that sounds like noise. Are you running twisted pair thermocouple wire all the way back from the thermocouple to the daughter board?

If it's a direct drive extruder then grounding the hot end metalwork may help.

Can you cinfirm that the thermocouple daughter board is the more recent type with MAX31856 chips and 2 LEDs?

[heoconnor]

@dc42 bought the thermocouple daughter board last summer. It says v1.1 on the back so I'm guessing not the most recent type.

Will look into grounding the hotend - thanks!