Instruction manual

ControlWave Gas Flow Computer (GFC Plus) Instruction Manual (CI-ControlWave GFC Plus)
3-12 I/O Configuration and Wiring Revised Feb-2013
3.3.7 Resistance Temperature Device (RTD) Inputs on CPU/System
Controller Board
CPU/System Controller Board connector TB6 provides connection to a
3-wire 100 ohm platinum bulb RTD (using the DIN 43760 curve).
Wire the RTD according to Table 3-9 and Figure 3-4 and Figure 3-5. In
this configuration, the return lead connects to the RTD- terminal and the
two junction leads (Sense and Excitation) connect to the RTD+ and
RTD EXC terminals.
Caution
Never ground the RTD cable shield at both ends or allow it to come in
contact with metallic/conductive conduit because multiple ground paths
can cause RTD input errors.
Table 3-9. RTD Connections to CPU/System Controller Board
Connector TB6
TB6 Pin Signal Function
1 RTD EXC Reference
2 RTD+ Sense
3 RTD- Return
Figure 3-4. 3-Wire RTD Temperature Input Wiring
Installing the RTD
Probe
To install the RTD probe, screw the fitting body into the thermowell
with a 7/8” open-end wrench. While you apply pressure against the
sheath to force the tip of the RTD probe into the bottom of the
thermowell (so that the probe tip is in contact with the bottom of the
thermowell), tighten the 9/16” nut using an open-end wrench against
the 7/8” fitting body.