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Digital Heater Element Burnout Detector


A high-precision Heater Element Burnout Detector compatible with a wide-range of heater control methods.

High-precision Heater Burnout Alarms with High-resolution Digital Measurement

Burnout Alarm Possible for One of Multiple Heater Elements

Heater burnout is detected by digitally processing minor current fluctuations.

K8AC-H Features 1

Push-in Terminals for Reduced Wiring Work (K8AC-H2[][][] Series Only)

Push-in terminals have no screws to come loose, which eliminates the need to control screw tightening torque and retighten screws and helps to reduce your workload.

K8AC-H Features 3

Easily connect terminals using ferrules with insulation sleeves.

Easy Scaling Using the External CT Ratio and Number of CT Passes (K8AC-H2[][][] Series Only)

Easily set the scaling just by inputting (1) the CT ratio and (2) the number of CT passes.

K8AC-H Features 4

Compatible with Various Heater Control Methods

Models with heater burnout alarms for ON/OFF control, phase control, and cyclic control have been added to the lineup.
Check the current input range, connected CT, and relay output type before selecting the model from the product specifications.
Note: Both single-phase and three-phase heaters are supported.

Overcurrent and SSR Failure Detection from Heater Layer Short Circuits.

• Overcurrent can be detected from layer short circuits in addition to providing heater burnout alarms with overcurrent
   detection settings.
• SSR short circuit failures and SSR open circuit failures are detected by monitoring the heater current and the control
   outputs from the temperature controller.
• Detecting SSR failures enables promptly discovering that temperature control has failed.

Heater Burnout Alarms for Cyclic Control or Phase Control Heaters (K8AC-H[][]P[])

The burnout detection value is shifted according to the control output value from the temperature controller.

• Analog control is performed on the output power according to the temperature controller's current output (4 to 20 mA)
   when phase control or cyclic control is used.
• Heater burnout alarms are stable with the K8AC-H because the heater burnout alarm values are linked with the control
   output value from the temperature controller.

K8AC-H Features 7

Compatible with Gradient Settings of Power Controllers

When using gradient settings with a power controller, set a gate current level that is suitable for the gradient settings.

Note: Set the heater burnout alarm value based on the current at the heater's rated input.

K8AC-H Features 8

The transistor output from the K8AC-H2[][]N can be used as either an NPN open-collector output or a PNP equivalent output.

The transistor output of the K8AC-H2[][]N uses a photocoupler for isolation with the internal circuits, and so either an NPN opencollector output or a PNP equivalent output can be used.

K8AC-H Features 9

Preventive Maintenance

The run time can be measured by the K8AC-H.

Managing the run time history until burnouts occur is useful for diagnosis and preventative maintenance for equipment.

Count the Total Number of Alarms Output

Set the upper and lower limits to count the total number of alarms that have been output.