Determining The Error From The Current Situation For Heater Burnout Alarm Errors - Omron EJ1 User Manual

Determining the Error from the Current Situation for Heater Burnout Alarm Errors

8-8 Determining the Error from the Current Situation for
Heater Burnout Alarm Errors
HB (Heater Burnout) Alarm or Heater Burnout Not Detected
Connection No current transformer (CT) is connected.
The CT is connected to the wrong channel.
Setting Control does not start.
The ON time for control output is less than 100 ms.
The HB alarm is not assigned to a control output or bus out-
put.
The heater power was turned ON after operation control
started.
The heater burnout detection current is set to 0.0 or 100 A.
The heater burnout detection current is the heater rated cur-
rent.
The measured heater burnout detection current is not suit-
able.
Procedure The heater current value exceeds 100 A.
The heater current is direct current (DC).
A pure metal heater is used.
Possible cause Countermeasure
• Connect a CT.
• Connect the CT to the correct channel.
• Start control.
• Set the control output ON time to 100 ms or more.
This will make the HB alarm operate.
• Assign an HB alarm to a control output or bus output.
• Turn ON the heater power then start operation control.
• Set an appropriate value between 0.1 and 99.9 A.
• Measure the heater current and set the detection current
value.
• Set the detection current again, taking into consideration
the voltage range of the heater power supply and current
measurement error.
• Reduce the value to 100 A or less.
• The HB alarm will not operate under these conditions.
• Measure the heater current and set the detection current
value.
Section 8-8
225