UZM-3-63: principle of operation, characteristics, connection diagram

Multifunctional protective device - this is how the name of this device stands. It is designed to protect three-phase consumers connected to the mains from voltage surges and phase failures. The maximum switched current per phase is 63 A. Next, we will consider the connection diagram, technical characteristics and the principle of operation of the UZM-3-63.

Appointment

The UZM-3-63 device is a voltage control relay equipped with a powerful three-phase power relay that switches a three-phase load. The relay is also equipped with a function that monitors the mains frequency. In addition, there is a function of suppression of impulse noise with semiconductor varistor protection. Interference, in turn, occurs during the switching of powerful devices and transients in electric motors and transformers. They have a devastating effect on microelectronics and other equipment. To perform switching UMZ-3-63 does not require external auxiliary switching devices (

starters or contactors), since there is a powerful built-in 63 ampere power relay.

Design

UZM-3-63 is manufactured in a housing for installation on DIN rail 35 mm wide. On the front cover there are bolted terminals for connecting wires, which can be seen in the photo:

Also on the front panel there are regulators of the maximum "U max" and the minimum voltage "U min", as well as a regulator of the time delay for the reclosing. Red indicator of overvoltage "U>", yellow light, signals about switching on the built-in power relay, as well as a red indicator light indicating a decrease in voltage "U

Below in a row are the phase indicators, green LEDs L1, L2, L3, signaling the presence of line voltage at the power terminals. At the top of the case of the multifunctional device, there are power input terminals marked N, L1, L2, L3, labeled as input. On the opposite side there are terminals labeled output and marked N, U, V, W. Also on UZM-3-63 there are terminals for connecting remote control: Y1, Y2.

Principle of operation

Now let's look at how the UZM-3-63 works. When electricity is applied to the input terminals, the green indicators L1, L2, L3 light up. The device measures input voltage, phase sequence, and mains AC frequency. If the parameters of the mains are normal and meet the set values, the reclosing time is set by the user. After that, the yellow indicator lights up and the power relay turns on, supplying electricity to the load.

If the network parameters do not correspond to the controller settings, the load is disconnected. Wherein:

• lit “U
• "U>" is on, it means the network parameters are higher than the set value;
• frequent simultaneous flashes of red indicators, which means the mains frequency does not correspond to the norm of 50 Hz;
• slow simultaneous blinking of these indicators signals about phase imbalance, the voltage between any of the phases differs by more than 25%.

Connection diagram

So, the connection of UZM-3-63 in a three-phase network occurs according to the following scheme:

Also, you should know some of the nuances that will allow you to correctly connect the UZM to the network:

• for the device to operate without remote control, terminals Y1, Y2 must be shorted together;
• the connection of the zero terminal N is necessary, which is necessary for the normal and safe operation of the device;
• the device does not know how to respond to short-circuit currents and leakage currents, therefore, it is necessary to install automatic devices and RCDs in the power circuit;
• UZM-3-63 works only with a three-phase load.

The recommended cross-section of wires for connecting the device is given in the table below:

If you are additionally interested in connection diagram UZM-51M, we provided it in a separate article, which we referred to!

Specifications

The dimensions of the multifunctional protection device are shown in the picture:

For the rest, I would like to note that UZM-3-63 is equipped with remote control terminals, monitors phase break and alternation, and controls the network frequency. In addition, the device can switch a large current, 63 amperes in one phase.

Of the possibilities, I would like to additionally highlight:

1. Overvoltage protection. Two-threshold smart shutdown with shutdown delay.
2. Defence from undervoltage. Two-threshold intelligent shutdown.
3. Built-in varistor protection against impulse noise.
4. Adjustable delay for re-enabling UZM.

All technical characteristics of UZM-3-63 are given in the table below:

So we examined the characteristics, the principle of operation and the connection diagram of the UZM-3-63. We hope the information provided was useful and interesting for you!

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