OMRON Electronics has released the K8AC-H digital heater-element burnout detector. It can detect heater element burnout faults in both cyclic and phase control systems. Other models can detect both SSR short-circuits and over current faults of heater elements in conventional on/off systems, controlled by SSR.
Both detection systems are available with either a single relay output for all faults or dual solid-state outputs, which differentiate between heater burnout/over-current alarms and SSR open or short-circuit faults.
To improve the accuracy of operation, the K8AC-H supports source voltage fluctuation compensation to ensure more stable readings. The in-built four-digit, seven-segment display shows heater current and power supply levels. There are also separate LED indicators for alarm conditions such as heater burnout, over-current detection, output SSR short circuit or open circuit.
The H8AC-H series accepts a wide range of ac inputs from a current transformer, with different models detecting 0.2A-2.2A, 2.2A-22A and 20A-200A. The K8AC-CT20S/20L/200 current transformers can provide these input signals. All models handle one and three-phase signals from one or two CTs. A gate input allows the K8AC-H to synchronise measurements with the heater control.
All units are powered by 100V-250V ac signal and support Omron's open CompoWay/F protocol. This protocol has been used for virtually all of Omron's discrete components that support communications. A twisted-pair RS485 signal is used, allowing up to 32 devices to be installed in the field, up to a distance of 500m from the communication control device.