Comparison Novatek-Electro RN-122 vs Novatek-Electro RN-116

The rated power of the relay in kilovolt-amperes, in other words, the maximum apparent load power with which the device can normally operate.

From a physical point of view, kilovolt-amperes and kilowatts mean the same thing, but in kW it is customary to indicate only the active power of the load (see below), and in kVA — full. In AC networks, these powers can vary because active power (the power consumed by resistive-type devices such as heaters) is added to reactive power (the power consumed by capacitors and inductors). The apparent power is calculated from these two quantities.

When selecting control relays for AC networks, it is best to take into account the full power, especially if you plan to connect equipment with electric motors to the device. However, for many modern household appliances, only active power is given in the characteristics — in kilowatts. There are calculation methods that allow converting active power into total power, depending on the type and characteristics of the load; such techniques can be found in special sources.

The device shutdown time on the upper limit of voltage or current. This is a kind of "reaction time" of the relay: the period of time between reaching the upper limit and turning off the protected network segment.

The lower this value, the more advanced the protection will be, the lower the probability of failure of sensitive devices due to untimely operation of the relay. Note that a short reaction time in this case is especially important, because too high a voltage or current is a serious danger to any device.

The lower voltage shutdown limit provided in the relay; when the voltage drops below this value, the device turns off the power to the protected network segment. Usually, this limit can be adjusted, and the specifications indicate the range of such adjustment.

Although the main danger for various electrical appliances is increased voltage, many devices do not tolerate too low voltage. Therefore, modern voltage relays provide shutdown not only on the upper, but also on the lower threshold.

The upper voltage shutdown limit provided in the relay is the voltage, when exceeded, the device turns off the power to the protected network segment. Usually, this limit can be adjusted, and the specifications indicate the range of such adjustment.

The method of managing the operating parameters provided in the device.

— Mechanical. Adjustment of parameters using mechanical switches, usually rotary, with scales printed next to them. In some models, these switches are manually adjusted, in others they must be turned with a screwdriver or other similar device. This method is simple, reliable and inexpensive, but not as convenient as digital adjustment, and has very low accuracy — for example, the re-closing time can be set with an accuracy of 20-30 seconds at best, and more often up to a minute or two.

— Digital. Adjustment of parameters using control electronic circuits. For such devices, it is mandatory to have a display: during adjustment, it displays a configurable parameter that can be changed by pressing the “+” (“Up”) and “—” (“Down”) buttons. Digital adjustment is somewhat more expensive than mechanical adjustment, but it significantly exceeds it in accuracy — the adjustment step can be 1 – 3 (seconds, volts, etc.).