Wiring Diagram; Section 2.9 Cold Junction Compensation - Spectrum Controls 1769 Series User Manual

2-16 Chapter 2: Installation and Wiring
NOTE
Section 2.8
Cold Junction
Compensation
WARNING
User's Manual Pub. 0300244-02 Rev. A

Wiring Diagram

Ungrounded Thermocouple
When using an ungrounded thermocouple, the shield must be connected to
ground at the module end.
To obtain accurate readings from each of the channels, the cold junction
temperature (temperature at the module's terminal junction between the
thermocouple wire and the input channel) must be compensated for. Two cold
junction compensating thermistors have been integrated in the removable
terminal block. These thermistors must remain installed to retain accuracy.
Do not remove or loosen the cold junction compensating thermistor
assemblies located on between the two upper and lower CJC terminals.
Both thermistor assemblies are critical to ensure accurate thermocouple
input readings at each channel. The module will operate in the
thermocouple mode, but at reduced accuracy if either CJC sensor is
removed. See Determining Open-Circuit Response (Bits 6 and 5).
If either of the thermistor assemblies are accidentally removed, re-install them by
connecting each one across each pair of CJC terminals.
NC
CJC0+
IN0+
CJC0-
IN0-
IN3+
IN1+
IN3-
IN1-
IN4+
IN2+
IN4-
IN2-
IN5+
CJC1-
IN5-
CJC1+
NC
Grounded Thermocouple