Voltage measuring range
Voltage measurement range supported by the device.
Many modern control relays are equipped with digital displays, which can display, including current voltage; this parameter specifies the operating range of the built-in voltmeter. In this case, the voltage measurement range can be noticeably wider than the difference between the smallest minimum and the largest maximum shutdown threshold (see below). This allows you to use the relay also for online diagnostics of the network status.
For a current relay (see "Device") in this case, the range of operating voltages can be given directly — the voltage at which the device can normally perform its functions.
Reclosing delay
The reclosing delay is the time after a safety shutdown after which the device turns on the mains power again. Usually, in modern control relays this time can be adjusted, so the characteristics indicate the range from the minimum to the maximum value.
Adjustment of the delay allows you to adjust the format of the relay to the characteristics of the network. So, if voltage failures do not mean critical problems, you can set the minimum re-closing time, and if jumps occur only with serious problems that need to be fixed, it is better to turn on the maximum delay. Note that triggered relays usually allow manual reclosing, and in most models it is possible to completely disable the automatic reclosing function.
Lower cut-off limit
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.
Upper cut-off limit
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.
Functions
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Display. As a rule, control relays are equipped with simple segment LCD displays that can display numbers and some special characters. This screen performs two main functions. Firstly, during operation it displays key network parameters - voltage, power and/or power, as well as notifications of problems; Some models provide several separate displays, each with its own parameter. Secondly, the screen is used when changing device settings.
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Operation indicator. A pointer indicating the operation of a device, and often a specific mode of operation. Note that in this case we are talking about the simplest indicators - for example, in the form of an LED, which lights up green in normal mode and lights up red after the protection is triggered. The display is not considered an operation indicator, although it can perform such a function.
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Thermal protection. A safety system that turns off the device when it reaches a critical temperature. Some models also provide a shutdown when the permissible heating rate is exceeded. This function serves as additional insurance in case of malfunctions in the relay itself (for example, if the settings are lost and the device does not respond to overload), and in case of fire (in case of fire, the equipment must be de-energized).
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Memory of emergency operations. The function
...of saving data on the state of the network during emergencies. Allows you to assess the situation of what happened after resuming work.Adjustment
The method of managing the operating parameters provided in the device.
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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.
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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.).
