There are many types of current sensors, perforated, screw-mounted, PCB, and rail mounted. There are many applications, such as high temperature, low temperature, high humidity, salt spray, vibration, etc., but the current sensor is used. The method is basically similar.
Like a conventional current sensor, a general Hall current sensor has four pins: positive (+), negative (-), measuring (M), and ground (0), but the line current sensor does not have these four pins. Instead, there are three lead wires of red, black, yellow and green, which correspond to the positive electrode, the negative electrode, the measuring end and the ground. At the same time, there is an inner hole in most of the sensors, and the current is passed through the inner hole when measuring the primary current. The size of the aperture has a certain relationship with the product model and the magnitude of the measured current.
Regardless of the type of current sensor, the wiring of the pins during installation should be wired according to the conditions stated in the instruction manual.
1) When measuring AC power, the bipolar power supply must be forced. That is, the positive (+) of the sensor is connected to the "+VA" terminal of the power supply, and the negative terminal is connected to the "-VA" terminal of the power supply. This connection is called a bipolar power supply. At the same time, the measuring terminal (M) is connected to the "0V" terminal of the power supply through a resistor (single-finger zero-magnetic formula).
2) When measuring DC current, use a unipolar or single-phase power supply, that is, short-circuit the positive or negative terminal to the “0V” terminal, so that only one electrode is connected.
In addition, the installation must take into account the product's purpose, model, range, installation environment. For example, the sensor should be installed as much as possible for heat dissipation.
In addition to the installation wiring, instant calibration calibration, and attention to the working environment of the sensor, you should also pay attention to the following items to ensure the test accuracy:
1) The primary side conductor should be placed in the center of the inner hole of the sensor, and should not be biased as much as possible;
2) The primary side conductor should be completely filled with the sensor inner hole as much as possible, leaving no gaps;
3) The current to be measured should be close to the sensor's standard rating IPN, not too much difference. If the conditions are limited, there is only one sensor with a high rated value, and the current value to be measured is lower than the rated value. In order to improve the measurement accuracy, the primary side wire can be wound a few times to make it close to the rated value. For example, when measuring a current of 10A with a sensor with a rating of 100A, to improve the accuracy, the primary conductor can be wound around the center of the inner hole of the sensor by ten turns (in general, NP=1; one turn in the inner hole, NP= 2;......; Around nine turns, NP=10, then NP×10A=100A is equal to the rated value of the sensor, which can improve the accuracy).
