1、Before putting a voltage transformer into operation, conduct test inspections in accordance with the items specified in the regulations. For example, measure polarity, check connection groups, test insulation resistance, and verify phase sequence.
2、Ensure the correct wiring of the voltage transformer: the primary winding should be connected in parallel with the measured circuit, and the secondary winding should be connected in parallel with the voltage coils of the connected measuring instruments, relay protection devices or automatic devices. Meanwhile, pay attention to the correctness of polarity.
3、The capacity of the load connected to the secondary side of the voltage transformer should be appropriate. The load shall not exceed its rated capacity; otherwise, the error of the transformer will increase, making it difficult to achieve accurate measurement.
4、Short circuit is not allowed on the secondary side of the voltage transformer. Due to the small internal impedance of the voltage transformer, a short circuit on the secondary circuit will cause a large current, which may damage secondary equipment and even endanger personal safety. A fuse can be installed on the secondary side to protect the transformer from damage caused by secondary short circuit. If possible, a fuse should also be installed on the primary side to protect the high-voltage power grid from risks to the primary system caused by faults in the transformer's high-voltage winding or leads.
5、To ensure personal safety when touching measuring instruments and relays, one point of the secondary winding of the voltage transformer must be grounded. After grounding, if the insulation between the primary and secondary windings is damaged, it can prevent high voltage from appearing on the instruments and relays, thus avoiding endangering personal safety.
6、Short circuit is absolutely prohibited on the secondary side of the voltage transformer.
