Thermon TraceNet TCM 18 - Manual (Page 17)

Figure 6: RTD Sensor Location
Where limiter RTD sensors are installed on the process piping it should follow the
guidelines above. In cases where the limiter is to be installed on the heater itself, it
is important to recognize that an offset should be anticipated in the limiter trip value
to allow for sensor reading error and overshoot.
As a general rule, field RTD wiring and power wiring should not be routed in the
same conduit or proximity in a tray as the temperature signals can become distorted
and result in improper readings.
Power Distribution Wiring and Breakers
All field power wiring materials used shall be suitable for the intended service and
shall be rated for insulation service temperatures up to and exceeding 221
◦ F (105 ◦ C)
unless otherwise higher values are noted in project specifications. Power supply
wiring from the power transformers to the power distribution panel and distribution
wiring to the heat trace circuits shall be rated for the heat trace use voltage or higher
and sized sufficiently large in wire size to minimize voltage drop. Circuit breakers
if not already supplied in the TraceNet panel should be selected based on the heat
trace cable type being used, the service voltage, and the circuit current draw charac-
teristics. It is especially important when using self regulating cable to make sure that
the circuit breaker response curve type is coordinated with the startup characteristic
of the heat trace cable in a cold start condition. All distribution wiring connections
should be tightened using a torque indicating screw driver to the levels indicated in
Table 1.
13 PN 50316_0514