6 Parameter Settings and Functions
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6.4.9 Heater burnout alarm [PAR4 → AL-1/AL-2/AL-3 → HBA]
When using a heater to raise the temperature of the control subject, the temperature
controller can be set to detect heater disconnection and send out an alarm by monitoring
power supply to the heater.
Heater disconnection is detected by the controller using a current transformer (CT), which
converts the current to the heater to a specific ratio (CT ratio) for monitoring. If the heater
current value [CT-A] measured by the CT is less than the heater detection set value
[AL□.L], the heater burnout alarm will activate.
Heater burnout detection only takes place when the temperature controller's output is
turned on. Otherwise, heater burnout will not be detected by the controller.
Detection is only available in models with switching output (Relay output, SSR drive output).
Models with linear output (current, SSR drive cycle/phase output) are incapable of detection.
Current detection is not performed if OUT1's control output time is less than 250ms.
It is recommended to use Autonics designated current transformer (for 50A).
Alarm output option can be set to standard alarm [AL-A] or alarm latch [AL-B].
In the case of TK4SP models, heater burnout alarm [HBA] mode is not available.
6.4.9.1 Heater burnout detection settings [PAR1 → AL!L/ AL@L/ AL#L]
Set the alarm output value [AL□.L] as the reference value for heater burnout detection.
Parameter Setting range
Unit
PAR1
AL!L
0)0 to 5)0 0)0 A AL@L
AL#L
Set to 0)0 for OFF. Set to 5)0 for ON.
Setting Value Calculation
: Heater Burnout Setting Value = {(Normal Heater Current) + (Heater Burnout Current)}/2