HRX-MM-N007
Chapter 3 Alarm Indication and Troubleshooting
3.3 Troubleshooting
HRS Series
3-52
1.
Flow rate of the circulating fluid is less than 5 L/min.
Install a flow meter, and check the flow rate of the circulating fluid.
2.
Check the pump performance.
Install a flow meter. Refer to the "Pump capacity" graph" shown in the catalogue and check that the
pump capacity is suitable for the circulating fluid outlet pressure and the circulating fluid flow rate.
3.
Circulating fluid is contaminated.
Contamination contained in the circulating fluid adheres to the heat exchanger (evaporator), and it
decreases the heat exchanger performance.
Open the cap of the tank, and check visually the contamination (e.g. deformation, foreign matter,
abnormal smell) of the circulating fluid inside the tank.
When the visual check finds contamination in the circulating fluid, check the influence of the
contamination to the heat exchanger by following the instructions shown below.
(1) Connect the circulating fluid outlet directly to the fluid return port with a valve mounted to the
outlet port with a shorter piping to make it possible to operate the system at flow rate of
circulating fluid at 7 L/min.
(For Option T, adjust the flow rate so that the circulating fluid discharge pressure will be
approximately 0.4 MPa.)
(2) Set the circulating fluid temperature to 20
o
C, and operate the Thermo-Chiller.
(3) Check the temperature shown for "t2: Circulating fluid return temperature" and "t3: Compressor
inlet temperature" in the "Check Monitor Menu".
(4) Displayed temperature will be as shown below in accordance with level of contamination of the
heat exchanger.
<With no contamination with the heat exchanger>
"t3: Suction temperature of the compressor" ≥ "t2: Circulating fluid return temperature" -5
o
C
<With contamination with the heat exchanger>
"t3: Suction temperature of the compressor" ˂ "t2: Circulating fluid return temperature" -5
o
C
e.g. (Normal) t2: 21.5, t3: 23.8, (Abnormal) t2: 21.5, t3: 15.5
4.
Check the compressor intake temp. sensor.
Check for any difference between the actual compressor intake temperature and the temperature
detected by the compressor intake temperature sensor by following the instructions shown below:
(1) Stop the Thermo-Chiller and leave it not operating for 24 hours to make the temperature of the
temperature sensor itself be the same as the ambient temperature.
(2) Check the temperature shown for "t1: Circulating fluid discharge temperature" and "t3:
Compressor inlet temperature" in the "Check Monitor Menu" of the Thermo-Chiller.
(3) If t3 = t1 +/- 3
o
C, it means that the compressor intake temperature sensor is operating correctly.
5.
Check the compressor intake temp. sensor after replacement.
Replace the compressor intake temperature sensor with a new one. (See document No.
HRX-MM-Q016 for replacement instructions) After replacing, check that all the check items shown in
"4. Check the compressor intake temperature sensor." are correctly followed.
