1. Isolation transformers are safety power supplies, generally used for machine maintenance and repair for protection, lightning protection, and filtering. An isolation transformer is a 1/1 transformer. The primary winding is single-phase 220V, and the secondary winding is also single-phase 220V. Alternatively, the primary winding can be three-phase 380V, and the secondary winding can also be three-phase 380V. Firstly, in our usual AC power supply, one wire is connected to ground, and the other wire has a 220V potential difference with ground. Contact with this can cause electric shock. However, the secondary winding of an isolation transformer is not connected to ground, and there is no potential difference between any two wires and ground. Contact with either wire will not cause electric shock, making it safer. Secondly, the output and input terminals of an isolation transformer are completely "open-circuited," effectively filtering the input voltage (the power supply voltage from the grid). This provides a clean power supply voltage to the electrical equipment.
2. The primary and secondary voltages are electrically isolated from each other. Either phase of the secondary voltage can be touched by hand without creating a circuit.
3. An isolation transformer, as the name suggests, separates the primary side (primary winding) from the secondary side (secondary winding). This is typically achieved through insulation measures, transforming high voltage into low voltage. Because of the insulation and the low voltage, there is usually no risk of electric shock; therefore, it is called a safety transformer.
A safety isolation transformer is a transformer that electrically separates its input winding from its output winding through insulation at least equivalent to double insulation or reinforced insulation. This type of transformer is designed to supply power to distribution circuits, electrical appliances, or other equipment at a safety extra-low voltage.
