Under certain conditions, such as high humidity, and in bathrooms, a decoupling is required electrical network and consumers in order to avoid serious electric shock in the event of a malfunction in devices. An isolation transformer will help to organize a safe connection.
Content
- Features of transformers
- Applications
- Isolation transformer design
- Connection method
Features of transformers
One of them is the presence of double insulation and / or a protective shield providing galvanic isolation, in contrast to from an ordinary device. This means that electrical energy is transmitted without direct contact between the windings. Separator provides protection from serious electric shock. If the insulation breaks through the housing inside the energy consumer, then the risk of electric shock while touching the device and a grounded object will be much lower.
Another feature of isolation transformers is that they have a conversion factor more often total is equal to one. Thus, the output voltage will be equal to the input - 220 volts. This variety is the most common. Transformers introduce some losses in the energy transmitted through it, since the efficiency is in the range - from 70 to 85 percent.
Applications
Isolation transformers are installed where a safe supply of electricity is required according to the current rules:
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In environments with high humidity, water, and poorly earthed metal (such as bathrooms, basements, and cable wells). This allows you to safely use common electrical appliances in these locations. The current regulations only allow the installation of sockets under these conditions when connected via an isolation transformer. - For example, if a hairdryer falls into a bathtub, the risk of an emergency will be minimized, since a closed circuit between the electrical network and a grounded object does not form. And when connected to an unprotected outlet, severe electric shock can occur, and in the worst case - fire of the insulation of the consumer's wires.
- In healthcare facilities to enhance safety and protect patients and staff from electric shock. In this case, isolation transformers can also be supplemented with devices for monitoring the state of insulation with remote posts. for remote tracking.
- This application is becoming more widespread in medical institutions in some developed countries.
- When connecting electrical tools of the first class of safety.
Isolation transformers of lower power are also used in broadcasting and organizational technology. For example, in high frequency amplifiers, receivers, signal splitters (splitters for ADSL and telephone), and computer Ethernet networks.
Isolation transformer design
Windings are wound on the magnetic core, between which there are at least two layers of reinforced insulation.
It is also possible with a special protective shield installed in addition to the basic insulation. The number of turns, as well as the thickness of the wire will be the same. It is then that the transformation ratio becomes equal to one. Due to the reinforced insulation and the winding screen, a galvanic isolation is created, and the consumer is completely separated from the earth. There are also other types of isolation transformers:
- step-downs for powering the lanterns;
- automatic;
- pulse;
- peak;
- measuring;
- high-frequency;
- power.
Connection method
A typical circuit looks like this: the primary winding is connected to the electrical network through a residual current device (RCD), which prevents current leakage. The device requiring protection is connected to the secondary winding forming an insulated circuit. It, as well as the consumer's case, must not be grounded. The rest of the devices can be connected directly to the primary circuit through a residual current device. In this case, grounding of their housings is allowed.
Thus, with the help of isolation transformers, it is possible to supply power to places where it would be unsafe to use a conventional electrical network. In this case, the effect of elementary safety rules is not canceled. For example, do not intentionally touch the terminals themselves. The same current flows through them as in the primary circuit, which can cause serious electrical injury. Isolation transformers must be installed by qualified personnel.
