Spectrum Controls 1746sc-NI8u - Manual (Page 33)

Chapter 2: Installing And Wiring Your Module 21
The module also has a ground terminal TB1 which should be grounded to
a chassis mounting bolt with 14 gauge wire.
Cold Junction Compensation (CJC)
CAUTION
POSSIBLE EQUIPMENT OPERATION
Do not remove or loosen the cold junction
compensating temperature transducers located on the
terminal block unless you are connecting remote CJCs
to the module. Both CJCs are critical to ensure
accurate thermocouple input readings at each channel.
The module will not operate in thermocouple mode if a
CJC is not connected.
Failure to observe this precaution can cause unintended
equipment operation and damage.
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 sensors have
been integrated in the removable terminal block. They must remain
installed to retain accuracy. If remote CJC compensation is desired,
the sensors at the terminal block must be removed and the external
sensors wired to the CJCA and CJCB terminals. The remote CJC
sensors must be Analog Devices AD592CN T0-92 style temperature
transducer devices. The module will not function with any other
CJC sensor connected.
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