An isolation transformer is such a transformer with electrical isolation between the input winding and the output winding. The isolation of the transformer is to isolate the respective currents of the primary and secondary windings and its one of functions is to protect individuals from electrical shocks between energized conductors and earth ground. Isolation transformer is a special transformer with high insulation between the primary and secondary windings to isolate different potentials and suppress interference. The transformation ratio of the isolation transformer is usually 1:1. In the early days, the 1 to 1 isolation transformer was frequently used in the power industry in European countries. For example, one galvanic isolation transformer could be widely used in the control power supply of general circuits, security lighting and indicator lights in the electronics industry, industrial and mining, machine tools and mechanical equipment.

Generally speaking, the neutral wire of the AC we usually use is grounded. Since there are many harmonics and tiny currents generated by stray magnetic fields in the alternating current, the interference is large. As what is said above, isolation transformer is a 1 to 1 transformer. If the primary voltage is 240V, then the secondary one is also 240V (more examples: 120V to 120V isolation transformer, 230V to 230V isolation transformer, 480V to 480V isolation transformer). The secondary of the isolation transformer is not connected to earth so that kinds of noise waves are reduced, thus there are less interference.

Isolation transformers plays a very important role in electrical safety when people use some electrical appliances in factory or at home. For instance, it is necessary for users to use a power isolation transformer when they repaire a TV. Because the power supply of the TV is connected to the mains, it will cause electric shock and endanger personal safety if the maintenance personnel accidentally touch this part of the circuit. Since isolation transformer is a 1 to 1 transformer, the numbers and diameter of primary and secondary windings are the same, namely, either primary winding or secondary winding can be connected to the mains. What should be paid attention to is that the power of the galvanic isolation transformer must be greater than that of the home appliances being repaired when repairers select an isolation transformer.

The electricity residents use is single-phase alternating current, there are two lines, one of which is the live wire (phase wire), the other is the neutral wire that is grounded. People will be electrocuted when they touch the live wire, because the human body has zero potential. However, an isolation transformer can solve the problem. When such a transformer is used, the voltage will not change though it is 1 to 1 transformer and as long as its secondary is not grounded, no one will get an electric shock if he touches any wire (note: only one wire can be touched at the same time).

Isolation transformers are commonly known as safety transformers, whose function is to isolate impurities from the grid and maintain some sensitive equipment, such as computers, medical equipment (medical isolation transformers), audio equipment, robot devices or laboratory instruments.

How to use an isolation transformer? First of all, we must first understand the power supply system of our own country. When supplying low-voltage users, most countries power supply systems generally adopt a three-phase four-wire system and the neutral wire is grounded. To put it simply, the wires in the residents homes are live wire (phase wire) and the neutral wire respectively, which has the same position with the earth. When the human body touches the bottom plate, the current will pass through the human body and form a loop with the ground, causing electric shock.

If an isolation transformer is used, it will be safer, because the primary and secondary exchange energy through a magnetic field, and there is no physical connection between them. Even if the human body touches electrically charged items, the electric potential of the charged part is low potential, which will not cause electric shock harm because of the same position of the human body and the earth. For example, the electric shock of a person is usually the process of the conductor's electricity flowing into the earth through the human body, and the reason why it flows into the earth is that its power supply equipment has an electrical relationship with the earth (the neutral point is grounded). If there is no such electrical relationship, then people will not suffer from electric shock.

There are two points we should know when we are using an isolation transformer. First, both of the secondary ends of the transformer can not be grounded. Additionally, the human can not touch both ends of the secondary at the same time, otherwise, electric shock will happen.


General Purposes of Isolation Transformer

1. Anti-interference: With Y/△ connection, isolation transformer (delta wye isolation transformer) can prevent the transmission of some harmonics.

2. Impedance transformation: Isolation transformer can increase system impedance, so that the protection device is easy to cooperate to use.

3. Stabilizing the system voltage: When a heavy load equipment needs start, isolation transformer will help reduce the impact on the system voltage.

4. Preventing system grounding: When single-phase grounding occurs on the load side of the isolation transformer, the whole system (above the isolation transformer) will not be single-phase grounded.

5. Reduce short-circuit current: When a short-circuit accident occurs on the load side, isolation transformer will limit the short-circuit current of the system.

Main Purpose of Isolation Transformer

The main function of the isolation transformer is to completely insulate the electricity between the primary side and the secondary side and also to isolate the circuit. In addition, high-frequency unclean waves will be suppressed following into the control loop due to the high-frequency loss of its iron core.

The dry type isolation transformer makes the secondary suspend to the ground only in some occasions where there is small power supply range, short circuits. In this case, the capacitive current of the system to the ground is too small to cause personal electric shock.

As one of reliable isolation transformer suppliers, Peaco Support provides a large selection of isolation transformers, whose capacity varies from 50VA to 2500 kVA, including single phase isolation transformers and three phase isolation transformers, featuring optional primary and secondary voltages ranging from 120V/ 230V/ 380V/ 440V/ 460V/ 480V, etc., enameled copper or aluminum wire. For instance, 240V to 110V isolation transformer, 120V to 100V isolation transformer, 480V to 480V isolation transformer, 440V to 220V isolation transformer are also availabe. In addition, the isolation transformer cost is low. Please contact us if you need custom isolation transformers.