ZET 7X20 TROUBLESHOOTING
- Check the offset voltage (2.5±0.1) V
Using a tester, check voltage between the “blue” output and the “common” output (white-orange).
- Check the thermocouple resistance.
Deenergize ZET 7X20 and measure resistance between the “red” and “blue” outputs. The resistance must be within 10 to 20 Ohm at ambient temperature.
Use only thermally-compensated cable for extending the cable between the TC and ZET 7X20.
- Thermocouple screening
If it’s impossible to measure the temperature accurately due to EMI, the TC needs screening. Connect the TP cable screen through a 15 nF 500 V condenser to the “Common” output for the measuring circuit power supply, as shown in the figure below: