the design

Modern microprocessor mechanisms used in the manufacture of the device provide ease of setup, simplicity of design and high reliability of parameters. If the equipment is imported, this is especially important, as they are particularly demanding on power supplies and require a high-quality power network. After all, even a minor accident can cause significant losses and failure of expensive equipment.

Below is the device connection diagram:

The design of the phase monitoring relay is based on a small circuit. She is the one who runs his business. As soon as the voltage drops (or disappears completely) in one of the phases, the microcircuit transmits a signal to the electromagnetic relay, disconnecting the load.

Also, the design of the RKF may include indicators of alternation and asymmetry of phase voltages, as well as a response time regulator.

an appointment

Since electrical equipment is used in almost all enterprises and its protection from phase imbalance and electric current drops is constantly necessary, relaying is applied in many areas of activity.

The mechanism is used to protect three-phase devices. The phase control relay protects against breakages, distortions or sticking, and also controls that each phase alternates correctly.

This unit may also have a function. Voltage Monitoring Relay – Monitors the magnitude of the voltage and cuts off the power at values ​​below the set point.

Operating principle

The principle of the device is self-resetting: the relay is disconnected when the alarm is triggered. When a three-phase voltage is received on the mechanism, all operating and control parameters are checked.

If during the examination it turns out that all parameters are normal, the built-in electromagnetic relay is triggered. If the control shows that at least one of the parameters does not comply with the norm, the mechanism turns off automatically. Then, after returning all parameters to the permissible norm, the device turns on automatically without delay. If not one phase is turned off, but two or three, then the device can be turned off without delay.

When any emergency occurs, the load is disconnected by the device. Emergency situations can be different, for example:

• No stage gone.
• Departure from the permissible limits of the voltage level (symmetric or asymmetric);
• Incorrect connection of three-phase power, as a result – incorrect rotation.

Such control using a similar design allows you to quickly and efficiently protect equipment from dangerous and emergency power supply modes of the electrical network, as well as monitor the quality of the electricity consumed.

Device types

There are a large number of phase control relays on the market today. One of the most popular types are the following:

• EL-13؛
• THE 12 ;
• 11.

In addition, modifications and models such as EL – 12 MT and EL – 11 MT have gained popularity and fame.

The EL-11 model and its modification EL-11 MT are used, as a rule, for the protection of generator sets and power supplies as well as in automatic standby transfer (ATS) schemes.

The relay model EL-12 and its modification EL-12 MT are mainly used to protect electric motors of lifting equipment with a capacity of not more than 100 kW.

The model EL-13 and its modification EL-13 MT control reversible electric motors with a capacity of not more than 75 kilowatts.

There are two ways to repair the device. The first option is to install with mounting bolts, and the second option is to install with DIN rail.

So we examined the purpose, principle of operation and control of the device relay. We hope it is now clear to you what this module is and why it is needed!