07 02, 2020
There are two main factors that determine the safety characteristics of the isolation transformer.
1. The secondary line of the isolation transformer is not connected to the earth.
First of all, understand that the general power supply system in my country generally uses a three-phase four-wire system when providing low-voltage voltage to users. The neutral wire is grounded, commonly known as a point. That is, one of the wires to the user's home is the live wire and the other is the neutral wire. It has the same status as the earth, and when a person standing on the ground touches a live wire or a conductor connected to the live wire, the current enters the human body from the live wire to the earth, forming a loop through the ground wire, causing electric shock. The secondary line of the isolation transformer is not connected to the earth, and there is no potential difference between any two lines of it and the earth. Therefore, under normal circumstances, when the user touches any line, no electric shock will occur.
2. The input end and output end of the isolation transformer are completely isolated, and there is an insulator in between.
The input and output terminals of the isolation transformer are independent and there is no common line. At the same time, when manufacturers make isolation transformers, they will apply insulating varnish on the outside of the windings. The wires used are what people often call "enameled wire", and the enameled wire can effectively achieve electrical isolation between the input and output terminals, thus being safe and effective. Avoid accidental contact with live objects and cause the user to get an electric shock.
But in fact, this "safety" is not absolute, there are two points that require special attention from users.
1. The user cannot touch the secondary ends of the isolation transformer at the same time, otherwise there will be a risk of electric shock.
2. Both ends of the secondary side of the isolation transformer cannot be grounded, otherwise there will be a risk of electric shock.