Conair Hopper Temperature Controller UGD031 - Manual (Page 75)

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Tr o u b l e s h o o t i n g l 6 - 1 1
C h e c k i n g o r R e p l a c i n g Te m p e r a t u r e
S e n s o r s
The HTC process air heater uses RTD sensors to monitor the process temperature
in the hopper inlet, the setback temperature in the hopper outlet, and the process
protection temperature in the heater outlet.
To check or replace an RTD sensors:
1 Disconnect and lockout the main power supply.
2 Locate the RTD sensors.
3 Check the sensor positions and conditions. Temperature readings will be
incorrect if the sensors are touching the wall of an air hose or pipe or if the sen-
sor or wiring is damaged. The tip of the sensor should be centered within the
air hose or pipe. Sensor wires should be attached to the appropriate connection
points on the heater’s control center.
4 To check with ohm meter, measure the resistance across the RTDs. The
resistance should be approximately 110 ohm at room temperature.
5 Replace the sensor, if necessary.
Typical loca-
tion of the
Process RTD
at the hopper
inlet.
IMPORTANT: Always refer
to the wiring diagrams
that came with your
heater to locate specific
electrical components.
Illustrations in the User
Guide are intended to be
representative only.
ON
O OFF