Thermon TraceNet TCM 18 - Manual (Page 68)

Improperly located RTD sensor. Is the RTD sensor installed next to a
heated tank or a steam jacketed pump
that might cause a higher than expected
reading? Is the RTD sensor on the heater
itself? Move the RTD sensor to location
more representative of the majority of the
piping. Is the sensor location representa-
tive for properly controlling under all flow
scenarios? Review location of the RTD(s)
with respect to the known process flow
patterns which occur and change as ap-
propriate.
Wrong insulation size, type, or thickness
on all of the line being traced. Measure circumference of insulation, di-
vide by π, and compare to insulation diam-
eter charts for proper over sizing. Check
insulation type and thickness against de-
sign specification. Replace insulation or
review system design for alternate oper-
ating possibilities.
Wrong insulation size, type, or thickness
on part of the line being traced. The insulation system should be as spec-
ified in the design for the entire circuit be-
ing traced. Having a lower heat loss on
one part of the circuit and higher heat loss
insulation on the other part of the circuit
(perhaps where the RTD sensor is) will re-
sult in the better insulated line being too
hot. Redo the insulation to assure unifor-
mity and consistency.
Damaged RTD temperature sensor. Disconnect RTD sensor and measure re-
sistance. Compare to resistance tables
for corresponding value of temperature.
Compare to pipe or equipment tempera-
ture known by another probe or sensor.
If different, the RTD sensor may need re-
placement.
PN 50316_0514 64