Transformer clamp ammeter construction diagram

The appearance of the transformer clamp ammeter is shown in Figure 1. It is mainly composed of a through-type current transformer and a magnetoelectric rectifier system measurement device, as shown in Figure 2.

Figure 1 Appearance of transformer type clamp ammeter

Figure 2 Transformer clamp ammeter structure

The transformer-type clamp-on ammeter has a current transformer with a core in the shape of a clamp mouth. When the wrench is tightened, the core can be opened, as shown by the dotted line in Figure 1. In this way, the current-carrying wire to be measured can be placed in the clamp-shaped core through the gap opened by the core without being disconnected. Then loosen the wrench to close the core, and the wire with the measured current becomes the primary winding N1 of the current transformer. The AC current I1 flowing through the measured wire generates an induced electromotive force in the secondary winding N2 through the closed core magnetic circuit, and an induced current I2 flows through the measurement circuit. The induced current I2 is rectified by the range change switch S according to different shunt ratios and becomes a DC current and is transferred to the meter head, causing the ammeter needle to deflect. Since the scale of the meter head is scaled according to the primary current I1, the reading indicated by the meter needle is the AC current value in the measured wire.