- Emerson Remote Terminal Unit Instruction Manual

CI-ControlWave Express Installation & Operation / 2-21
2.3.5 RTD Wiring
A 3-wire RTD may be provided with the ControlWave Express (equipped with a 14MHz
CPU/System Controller Board). Connector TB6 on the CPU/System Controller Board
accommodates a removable three-wire Terminal Block (TB6). This connector accommodates
a 100-ohm platinum bulb using the DIN 43760 curve. ControlWave Express RTUs use the
common three-wire configuration. In this configuration, the Return lead connects to RTD-
and the two junction leads (Sense and Excitation), connect to RTD+ and RTD EXC.
Connection between the RTD and CPU/System Controller Board is wired per Table 2-10
and Figure 2-11.
Table 2-10 - RTD Connections to CPU/System Controller Board Connector TB6
TB6 Pin Signal Function
1 RTD EXC Reference
2 RTD+ Sense
3 RTD- Return
Never ground the RTD Cable Shield at both ends or allow it to come in contact with
metallic/conductive conduit as multiple ground paths could cause RTD input errors.
To install the RTD Probe, screw the Fitting Body into the thermowell with a 7/8”open-end
wrench. While applying 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 thermowell),
tighten the Nut (9/16” open-end wrench) against the 7/8” Fitting Body (see Figure 2-12).
Figure 2-11 - 3-Wire RTD Temperature Input Wiring
Figure 2-12 - RTD Probe Installation/Removal Diagram
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