Why doesn’t grounding a single voltage transformer create a grounding circuit?

Because the secondary grounding of the transformer does not form a circuit with the main power supply

When a single voltage transformer is grounded, no grounding circuit is formed for the following reasons: 1. A voltage transformer is a measuring instrument whose primary function is to transform high voltages into low voltages for use in measurement and protection devices. Its input and output terminals are designed to be insulated, so under normal operating conditions, no current flows between the output terminal and ground; in other words, there is no ground current. 2. When a single voltage transformer is grounded, its grounding point is insulated and not connected to the grounding points of other electrical equipment or facilities. Therefore, even if grounded, it will not result in the formation of a ground circuit. It should be noted that if multiple voltage transformers are connected through a common grounding point, a grounding loop is formed at that point, which may cause grounding current to flow and affect the safety of equipment and personnel. Therefore, in practical applications, it is necessary to plan the grounding design properly to ensure the safety and reliability of the grounding system. .

Won’t the voltage induced by that second measurement cause a ground short circuit?

The induced voltage measured on the secondary side is generated by the windings of the transformer, as a result of the interaction with the current in the main circuit. When the secondary side of the transformer is grounded, it does not cause a short circuit. The reason is that the secondary winding of the transformer is designed to be insulated; under normal operating conditions, it is separated from ground by an insulating layer, so grounding does not cause a direct short circuit. Furthermore, the insulation performance of transformers is generally required to meet relevant **standards and specifications, ensuring their safe and reliable use. It should be noted that if the insulation layer of the transformer is damaged or aged, it may lead to insulation failure; in such a case, grounding on the secondary side can cause a short circuit. Therefore, when using transformers, it is necessary to regularly check the insulation condition to ensure it remains intact and to avoid potential safety hazards. .

Just like in the main circuit, if no secondary loop is formed, there won’t be any short circuits.

I didn’t understand what the questioner meant; a voltage transformer is grounded and can withstand the rated voltage.