150/5 multi core current transformer 1 through the heart, 30 times. 2 wear heart, 15 times. 3 through the heart, 10 times 5 through the heart, 6 times. In short, you use the rate of 1, divided by the number of heart, is the actual rate. The magnification mainly depends on the magnitude of the primary current and the current measured or controlled by the secondary side. Generally, the secondary side nominal current of the current transformer is 5A.
The main reason is to select the appropriate current transformer primary current nominal value (close to the transformer nominal current value) according to the supply current of the AC power source or the current of the power load. For example, if the rated current of the power distribution cabinet to a certain line is 1450A, then the current transformer of 1500A/5A should be selected, and the three-phase 5A watt-hour meter should be used, then the magnification is 150.