Inferring Causes From Conditions (Abnormal Control); (Abnormal Measured Values) - Omron E5AR - MANUAL 2 User Manual

10.4 Inferring causes from conditions (abnormal control)

● The PV does not rise
Abnormal measured value.
A load is not connected to the control output
terminal.
Incorrect load polarity or incorrect terminal
connections.
The terminal connection screws are loose, resulting
in a bad connection.
The heater power is not turned on.
The heater has a broken wire or has deteriorated.
The heater has a low heat capacity.
The overheating prevention device has activated.
Direct action and reverse action settings are
incorrect.
The PID values are not suitable.
Control has not been started.
The output does not increase due to MV limits.
The cooling fan is running.
● The measured value rises above the SP
Abnormal measured value.
The load is connected to the wrong channel and
the heater is being controlled by the control output
of another channel.
The contact of the control output drive relay has
melted.
Short-circuit failure in SSR.
Current flows to heater due to SSR leakage
current.
Direct action and reverse action settings are
incorrect.
The PID values are not suitable.
The output does not decrease due to MV limits.
Output is taking place in manual mode.
The object of control generates heat.
Large overshoot.

10.4 Inferring causes from conditions (abnormal control)

Possible cause
Possible cause
Solution
Solve as explained in section 10.3.
Connect a load.
Wire correctly.
Tighten the screws securely.
Turn on the heater power.
Replace the heater.
• Change to a heater with a high heat capacity.
• If using two or more heaters, replace any
heaters that have broken wires.
Increase the temperature setting of the
overheating prevention device to a value higher
than the SP of the E5AR/ER.
Set the correct settings.
• Run AT.
• Set suitable PID values.
Start control.
Change the output limits to suitable values.
Stop the cooling fan.
Solution
See section 10.3.
Wire correctly.
Replace the relay.
Replace the SSR.
Connect a bleeder resistor to prevent action due
to leakage current.
Set the correct settings.
• Run AT.
• Set suitable PID values.
Change the output limits to suitable values.
Stop manual mode.
Use heating/cooling control.
See the "Overshoot or undershoot"
troubleshooting table.
10-5