Troubleshooting Traulsen Intela-Traul Sensors - Traulsen G Series Manual

I. d - Troubleshooting Traulsen Intela-Traul Sensors
Sensor Function:
•
Cabinet Sensor (Green): The Cabinet sensor reads the temperature of the return air
and relays that value back to the control head. The control head either cycles the
compressor on or off depending on the temperature set points. If cabinet sensor reads
60⁰F (15 ⁰C) or higher the unit will not go into defrost and you can't put into manual
defrost.
•
Coil Sensor (Blue): The Coil sensor reads the evaporator coil core temperature and
returns that value back to the control head. The control head uses this input to terminate
the defrost cycle at 45⁰F (7.2⁰C) evaporator core temperature. In addition the control head
uses the evaporator coil core temperature to control evaporator fan delay.
•
Liquid Line Sensor (Yellow): The Liquid Line sensor reads the temperature of the liquid
line and returns that value back to the control head. The control head uses the liquid line
temperature to trigger a clean coil alarm at 140⁰F (60⁰C) (R&A series only) & cycles the
compressor off on high temp limit at 160⁰F (71.1⁰C) liquid line temperature.
Basic Troubleshooting:
All sensors (cabinet, coil, liquid line) can be tested for accuracy using a Volt Ohm Meter.
•
When checking a sensor value through the control a reading of -40⁰F (-40⁰C) indicates an
open in the sensor or sensor circuit and a reading of 266⁰F (130⁰C) indicates a short in
the sensor or sensor circuit. See Table 4 for control head sensor parameters.
•
An ice & water solution consisting of mostly ice with just enough water to submerse the
sensor should be used to create a controlled environment of approximately 32⁰F (0⁰C).
This solution likely needs to be agitated or stirred to maintain a consistent temperature
throughout. At 32⁰F (0⁰C) all sensors should return an Ohm reading of 32,000 Ohms +/-
10%. See Table 5 below for temperature & Ohms relationship of all Intela-Traul
sensors.
Sensor
Cabinet Air
Evaporator Coil
Liquid Line
Table 4
Parameter
O
TEMP ( F) R (OHMS)
46.2K 
20
39.9K 
25
34.6K 
30
32.7K 
32
30.1K 
35
26.1K 
40
Table 5
O
TEMP ( C)
-6.7
-3.9
-1.1
0.0
1.7
4.4
7