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Determining the Error from the Current Situation for Temperature Control Errors
Section 7-6
7-6
Determining the Error from the Current Situation for
Temperature Control Errors
Temperature Is Not Rising
The Measured Temperature Increases Above the Control Temperature
Possible cause
Countermeasure
Connection Measured temperature is wrong.
• Perform the action outlined in 7.5.
No load is connected to the control output terminal.
• Connect a load.
The load polarity or connected terminals are wrong.
• Rewire correctly.
The connection terminal screws are loose and the connec-
tion is imperfect.
• Tighten the screws securely.
The heater power is not turned ON.
• Turn ON the heater power.
Heater is burnt out or deteriorated.
• Replace with a better quality heater.
The heater's heating capacity is insufficient.
• Replace with a heater with a bigger heating capacity.
• If more than one heater is used, check for burnt out heaters
and replace if necessary.
An overheating protection device is operating.
• Set the set value for the overheating protection device to
higher than the EJ1G set point.
Setting
The normal and reverse operation settings are incorrect.
• Make the correct settings.
The PID constant is unsuitable.
• Execute gradient tuning (GT) or autotuning (AT).
• Set a suitable PID constant.
RUN/STOP is set to STOP.
• Set to RUN.
Operation After Power ON is set to STOP status.
• Set RUN/STOP to RUN.
• To change to RUN the next time the power is turned ON,
set Operation After Power ON to Continue and turn OFF
the power while in RUN mode.
The MV limiter is preventing the MV from increasing.
• Change the MV limiter to a suitable value.
A cooling fan is operating.
• Stop the cooling fan.
Possible cause
Countermeasure
Connection Measured temperature is wrong.
• Perform the action outlined in 7.5.
The load is connected to the incorrect channel so the heater
is being controlled using control output from another chan-
nel.
• Rewire correctly.
The contacts for the relay driven by control outputs are
welded together.
• Replace with a higher quality relay.
The SSR has short-circuited.
• Replace with a better quality SSR.
Leakage current from the SSR is flowing to the heater.
• Connect breeder resistance to prevent the action of leak-
age current.
Settings
The normal and reverse operation settings are incorrect.
• Make the correct settings.
The PID constant is unsuitable.
• Execute gradient tuning (GT) or autotuning (AT).
• Set a suitable PID constant.
The MV limiter is preventing the MV from decreasing.
• Change the MV limiter to a suitable value.
The EJ1G is outputting in manual mode.
• Stop manual mode.
Procedure
The control system is radiating heat.
• Execute heating and cooling control.
The overshoot is too large.
• Use the countermeasures listed in the Overshooting or
Undershooting troubleshooting table.
Summary of Contents for EJ1G
Page 3: ...iv ...
Page 17: ...xviii ...
Page 21: ...xxii ...
Page 53: ...32 Unit Configuration Examples Section 2 4 ...
Page 69: ...48 Changing SPs During Operation Section 3 3 ...
Page 81: ...60 Other Functions Section 4 5 ...
Page 145: ...124 Other HFU Functions Section 5 7 ...
Page 167: ...146 Detailed Description of Services Section 6 4 ...
Page 229: ...208 Parameters That Can Be Allocated for Programless Communications Appendix ...
Page 237: ......