SMC Networks HRS012-A-10 Series Service Manual page 49

External load is out of the specification range.
1.
Cooling capacity varies depending on the ambient temperature, facility water temperature, set
circulating fluid temperature, and power supply frequency.
Please refer to the "Cooling capacity" graph shown in the Operation Manual.
2. The alarm goes off right after the Thermo-Chiller starts.
Check if the the Thermo-Chiller has a circuit that the circulating fluid that has been heated to 60
or more by a waste heat of the workpiece that is cooled returns to the Thermo-Chiller at once when
the Thermo-Chiller starts operation.
Check the external piping.
3.
Check if the Thermo-Chiller has a circuit that high temperature circulating fluid returns to the
Thermo-Chiller at once due to an operation of the valve or the switching valve in the external piping.
Check the circulating fluid temperature sensor (PT2).
4.
Two circulating fluid temperature sensors are used; one is for the outlet port (PT1) and the other is
for the return port (PT2). Compare the temperatures sensed by the temperature sensors under the
conditions shown below to judge if the values provided by the temperature sensors are correct or
not:
(1) Connect a shorter pipe directly from the circulating fluid outlet port to the return port of the
Thermo-Chiller with a valve mounted to the outlet port. (Mount a valve to the outlet port to make
it possible to adjust the flow rate roughly.)
(2) Operate the Thermo-Chiller and stabilize the temperature.
(3) Check the temperature shown for "t1: Circulating fluid outlet temperature" and "t2: Circulating
fluid return temperature" in the "Check Monitor Menu".
If the temperature is within the range of t2 = t1 +/- 2
temperature sensor (PT2) is normal.
Check the circulating fluid temperature sensor (PT2) after it is replaced.
5.
Replace the circulating fluid temperature sensor (PT2). (See section "4.5.2 Replacement of the
temperature sensor (PT2)" for the replacement procedure.) After replacing, check that all the check
items shown in "4. Check the circulating fluid temperature sensor (PT2)" are correctly followed.
HRS Series
Chapter 3 Alarm Indication and Troubleshooting
o
C, operation of the circulating fluid
HRX-MM-N007
o
C
3.3 Troubleshooting
3-33