A voltage monitoring relay is a protective device that is used for establishing voltage control. There are many different kinds of voltage monitoring relays, depending on the function that they are meant to perform. The basic function of this relays is to receive the input signals and then monitor them and determine them. If the value is reached, an alarm signal is set out. It is extremely essential equipment, as it helps to protect the important products and devices against problems of overcurrents and overvoltage faults. These relays are used for monitoring the AC power supplies, analog signals, and other temperatures which help to detect the abnormalities in machines by observing the values against alarm thresholds. An alarm signal can also go off if any input signal turns into an abnormal status. This signal is to stop the equipment and prevent it from damage.
Where Can Voltage Monitoring Relays Be Introduced?
If you ever get to visit any production site, you will see an exorbitant range of machines operating at a time. These machines are used as sources of power for heaters and motors on the production lines. If any machine faces any kind of mishap, the products will be formed defective and sometimes the production equipment may also stand damaged. Device protection is the technique of monitoring the status of the main power circuit of the industrial production equipment and machines from problems like overvoltage, low-voltage over-currents, or other faults.
How Can Voltage Monitoring Relays Help?
A voltage monitoring relay can either be used as an under-voltage or an overvoltage relay. This, however, depends on the kind of output contact being used.
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Undervoltage Relay: This kind of voltage monitoring relay helps to provide protection to a machine or equipment that is needed to operate above a specific minimum voltage. This kind of relay harnesses the use of normally open contact. As long as the monitored voltage exceeds the minimum value which is needed, the relay will be energized and the normally open contact closes, which then turns on the load. However, if the voltage drops below the minimum value required, the relay will be de-energized, causing the normally open contact to reopen and turn the load off.
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Overvoltage Relay: This kind of relay helps to provide protection to those machines that are unable to handle any excess voltage. An overvoltage relay incorporates the use of a normally closed contact. In contrast to what we saw in the previous case, in this case, as long as the monitored voltage stays lower than the maximum voltage which the equipment can bear, the relay stays de-energized and the normally closed contact remains closed. This keeps the load energized. Similarly, if the operating voltage reaches a level more than the machine’s maximum rating, then the relay energizes, opening the NC contact and turning the load off.
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Over and Under Voltage Monitoring Relay: Apart from these two cases, another kind of relay is Over and Under Voltage Relay. This is more popularly known as a voltage band. A voltage band helps to provide protection to machines and equipment which are needed to operate within a range of upper and lower voltage. The internal relay remains energized as long as the voltage, which is operating, is within a range of under and overvoltage. However, if the voltage drops outside the specified range, then the relay will drop-out, thereby protecting the machine from any further damage.
Conclusion
I hope this gives you an overall idea about the function of a voltage monitoring relay and how it helps to safeguard heavy machines. They are of utmost importance if you want to keep your machine in working condition for a long time.
