The AHT8A Current Flow Indicator is designed for monitoring of AC current flow in eight independent circuits. The output information has two states (the current flows - doesn't flow). The typical application of the indicator is the current flow monitoring in electrical heating circuits with solid state relays.
Properties
The device has no connection terminals for the monitored circuit - the corresponding conductor is drawn through the hole in the current sensor. The hole has the diameter 9 mm and the maximum size of the conductor is 16 mm2. The current range is 1,8 to 200 A.
The current flow is indicated by LEDs on the device and by floating transistor outputs, which can be connected for example to the inputs of the control system. While the LEDs indicate the instantaneous status of current flow, the transistor outputs turn off with a delay in order to facilitate the evaluation. The delay (short or long) can be set individually for each circuit by a jumper on the device's board. In most cases the short delay is used, which ensures only the covering of the zero-crossing of the monitored current. In such case the circuit can be checked both on break and on the short-circuit of the switching element. The long turn-off delay is useful for monitoring the circuits switched with PWM (Power Width Modulation). However in this case the circuit can be checked only on break during the normal operation. The floating transistor outputs need no external power and can be serially connected.
The device is powered by 24 V DC. Both the power and outputs are on connectors with screw terminals. The physical dimensions are 190 × 90 × 95 mm (W × H × D). The device is designed for mounting on standard 35 mm DIN rail.
