1. The secondary winding of the high-voltage current transformer is not allowed to open circuit, otherwise it will generate high voltage and endanger the safety of equipment and operators. At the same time, due to overheating of the iron core, it may burn out the transformer and increase the error of the current transformer. Therefore, when working in the secondary circuit, the secondary side of the current transformer should be short circuited first.
2. Avoid using both relay protection and current transformers for electrical energy measurement, otherwise due to the requirements of relay protection, the selection of current transformer ratio is too large, which affects the accuracy of electrical energy measurement. For billing users, dedicated metering current transformers or current transformers with metering windings should be installed.
3. The primary winding of the high-voltage current transformer is connected in series with the tested circuit, and the secondary winding is connected in series with the electrical measuring instrument. When wiring, attention must be paid to the polarity of the current transformer. When the lead of the coil inside the current transformer is connected to the wrong position and terminal button, and when the mark is wrong, the polarity of the coil is reversed. Only by correctly connecting the polarity can measurements and measurements be accurate.
4. When the range of load changes is large and the actual load current is less than 30%, current transformers with secondary winding tap ratio or 0.5s and 0.2s current transformers should be used, or higher level short-term heating should be used. Small range current transformer with current and dynamic stable current, close to the actual load current
5. One end of the secondary side of the high-voltage current transformer should be reliably grounded, and there should be only one grounding point. To prevent damage to personnel and equipment during the breakdown of primary and secondary insulation.
6. The connecting wire of the secondary circuit should be copper single core insulated wire. It is strictly prohibited to use aluminum wire, and there should be no joints in the middle. The cross-sectional area of the conductor in the current secondary circuit should not be less than 4mm2.
7. The sequence and current phase should be correct. For example, in the 24 group combination wiring of a three-phase three wire active energy meter, only when the component is connected to u and i, and the second component is connected to u and i, the energy measurement is correct, and other wiring methods are incorrect.