Electric motors are one of the backbone components of the industry. Thanks to the motors, the desired mechanical power in the industry is provided. In our country, electric motors alone constitute about 36% of the electrical energy consumed in the industry. For this reason, efficient and uninterrupted operation of electric motors is very important for both energy efficiency and production efficiency for a business. Digital motor protection relays are an effective and simple measure to protect electric motors against possible malfunctions. However, digital motor protection relays should be chosen correctly according to the motor and application variety, and should provide a smarter and more efficient solution these days when we talk about industry 4.0. In this article, we will cover our expectations from an ideal digital motor protection relay.
It is especially important to protect high power and expensive electric motors.
First of all, a digital motor protection relay should be considered from 3 aspects.
• Protection Features
• Diagnostic features
• Integration Features
The most basic protection function of a digital motor protection relay is thermal overload protection. In this form of protection, the relay measures the current consumed by the electric motor and applies the thermal overload model to simulate the heat value inside the electric motor. The product to be selected must take into account the starting and working load characteristics of the electric motor. In particular, if a protection is to be provided for large power or medium/high voltage electric motors, it is important to simulate more precisely the heat content inside the electric motor.
The second most important protection feature to be considered is the Phase Loss protection. Phase loss is one of the important causes of motor failures and occurs when the current value of one or more of the phases is equal to instantaneous/continuous 0 amps. Usually this is caused by a blown fuse or a contactor that has lost contact permeability. Traditional phase protection algorithms or solutions may take half an hour, sometimes longer, to detect phase loss. Prolonged exposure to phase loss will cause serious damage to the electric motor. Most of the time, the reason why the windings we see in the industry are irreversibly damaged is exposure to this situation. Electronic motor protection relays, on the other hand, can detect a phase loss situation in less than three seconds, so your motor is protected at the start of a fault.
Other protection features to be considered for proactive motor and machine protection include earth fault current, unbalanced load, overvoltage, etc. Large and expensive motors should take advantage of these additional protection features that can stop the electric motor to prevent damage before traditional protection algorithms and methods. These additional protection features can only be achieved with electronic motor protection relays. Moreover, in electronic motor protection relays, the opening time, reset time, current RMS, earth fault current, voltage RMS, power, energy values can be measured and changes can be made. This information is useful when protecting expensive or process critical motors.
The last design feature to consider is the integration features that overload relays provide. Electronic/Digital motor protection relays have a wide current range that helps to minimize the number of equipment required to protect the wide motor power range. Digital motor protection relays are mounted directly on the load side of the contactor and save installation time, space and wiring. On the other hand, motor protection relays offer removable terminal blocks to minimize replacement time.
The 3 basic elements mentioned above, protection, diagnosis and integration are provided by LS Electric DMP Electronic Overcurrent Protection relays. Thanks to its powerful microprocessor structure, it not only provides superior protection for your engine, but also allows you to monitor your business data.
DMP Electronic Motor Protection Relay | Many Features in One Smart Product
– Microprocessors in its structure collect and process real-time data
-Phase fault, over current, asymmetry fault, reverse phase, phase unbalance, short circuit and earth fault protection function
-You can easily check the engine load status.
– It is not affected by harmonics, so it can be used safely even in facilities where ac drives are used heavily.
– CE, UL, cUL, Lloyd certification.
It can be used as an optional ammeter.
