Voltage control relays

Voltage control relay

Voltage control relays control the magnitude of the alternating voltage in low-voltage electrical networks. They are installed at the input to the switchboard together with other protective devices. Depending on the magnitude of the operating voltage and the type of protected low-voltage electrical network (1p / 3p), single-phase / three-phase voltage control relays are used.

Learn more

In a typical situation, when single-phase consumers are powered by a three-phase input, it is advisable to use a "universal" three-phase voltage control relay (e.control. v04m), which is designed for continuous control of the value in three-phase and single-phase circuits as well as for protecting electricity consumers from increased or decreased voltage. Voltage measurement method - real rms value. Its technical characteristics are as follows:

Nominal voltage when connecting L1, L2, L3, V - 380, 400, 415
Nominal voltage at connection L1, L2, L3, N, V - 220, 230, 240
Frequency Hz 50
Upper limit trigger setting,% 105-130
Lower limit trigger setting,% 70-95
Maximum operating current, A 8
Contact - 1NO+1NC
Number of modules - 1

Types of voltage control relays

To control the supply voltage value / protect three-phase consumers, we select a three-wire connection scheme (L1, L2, L3), with the switch for selecting the supply voltage value in the 3P3W position; to protect single-phase consumers connected to a three-phase input, a four-wire connection scheme (L1, L2, L3, N) is used; the switch must be in the 3P4W position. Switching from three-wire to four-wire mode must be carried out with the voltage removed.

Реле за контрол на напрежение1 | Енекст България — Voltage control relay three-phase adjustable e.control.v04m

The method of connecting a voltage control relay depends on the value of the rated current that the voltage control relay contact group can withstand for an unlimited time.

If the rated current of the contact group of the voltage control relay is equal to or greater than the value of the current consumed by the load, and the load itself does not create large starting currents when turned on and does not operate in heavy modes, then the voltage control relay is connected in series , and if they are less - then the voltage control relay is connected in parallel. When connected in parallel, the voltage control relay is used to control a contactor that can withstand the rated current consumed by the load. In this case, only the current of its own consumption will flow through the voltage control relay, and the power consumed by the contactor coil will be much less than the power consumed by the load. Therefore, even a voltage control relay with a small value of the rated current of the contact group can fulfill this functional task.

There is a misconception that it is enough to install a voltage control relay and this will provide full protection against emergency situations. The voltage control relay does not protect against overvoltages, for these purposes it is necessary to additionally use surge protection devices and surge arresters. Only a complete combination of all protection and control devices will provide the required level of protection.

It is worth adding that in standard models of voltage control relays there is no built-in protection against short-circuit and overload currents, therefore, according to the wiring diagram, a protective circuit breaker must be installed in front of the voltage control relay. Information on the principle of connecting the voltage control relay is available in the device passport.

Реле за контрол на напрежение2 | Енекст България — **Three-phase voltage control relay, digital e.control.v06**

Protective devices installed separately from other protective devices will not provide the full range of protection. The circuit breaker cannot control the voltage, and the voltage control relay is not designed to protect against short-circuit/overload overcurrent and atmospheric surges. Therefore, it makes sense to put a full set of protective devices and voltage control relays at the design stage of low-voltage electrical networks of facilities. Comprehensive protection will be the best solution in this situation and will contribute to the correct operation of the voltage control relay.

In addition to single-function voltage control relays, the range includes multifunctional voltage control relays, which, in addition to continuous monitoring of the mains voltage, also perform other functional tasks. One such voltage relay is the Voltage Control Relay, Digital e.control.v06. This voltage control relay is designed for continuous control of:
— the values of three-phase alternating current voltage and protection of electricity consumers from increased or decreased voltage;
— correct phase sequence;
— symmetry of the mains voltage;
— full-phase mains voltage;

Types of voltage control relays

Structurally, voltage control relays are divided into unregulated voltage control relays and regulated voltage control relays. In unregulated voltage control relays, the values of the upper and lower limits of the tripping voltage are set at the factory and cannot be changed by the user. One such voltage control relay is our voltage control relay, three-phase e.control.v03m, which is designed for continuous control of the value in three-phase and single-phase circuits, as well as for protecting electricity consumers from increased or decreased voltage. Voltage measurement method - real root mean square value. In adjustable voltage control relays, the user can change the response voltage value according to the upper and lower limits thanks to the buttons on the voltage control relay housing, as well as the time interval for switching on after restoring the network voltage parameters to the preset ranges. One such voltage control relay is voltage control relay, single-phase e.control.v02

Реле за контрол на напрежение3 | Енекст България — **Voltage and current control relay 25A e.control.v10**

The working principle of the voltage control relay

If the mains voltage deviates upwards or downwards from the set limit values, the load is disconnected from the mains.

After restoration/normalization of the mains voltage parameters, the position of the contact group of the voltage control relay changes automatically with a preset or set time-delay. When the voltage control relay operates in conjunction with a contactor, the load will be switched on automatically if the voltage control relay is connected in combination with an independent release of the input circuit breaker; restart is done in manual mode.

Реле за контрол на напрежение4 | Енекст България — **Voltage control relay, single-phase e.control.v00, 63A**

Why buy a voltage control relay from us?

Our product range includes a wide and continuously updated range of voltage control relays, covering the entire range of requirements of design and installation organizations and the needs of household consumers.

Реле за контрол на напрежение5 | Енекст България — **Automatic load transfer relay e.control.v12**

You can purchase single-phase (three-phase) voltage control relays from our physical stores, or choose from our official online store, and you will receive fast delivery to an address of your choice or a courier company office.

Voltage control relay
Types of voltage control relays
Types of voltage control relays
The working principle of the voltage control relay
Why buy a voltage control relay from us?