Intelligent Motor Protection Relays: Monitoring, Protection, Control
Electrical motors might be called the “quarterback” of industrial activity. Intelligent motor protection relays can be considered the protective defensive line for monitoring, calculating and communicating potential overcurrent or overload conditions. Motor protection is used in residential (e.g., HVAC), commercial, and industrial facilities. Electrical professionals need to thoroughly understand the basic principles of motor protection and relay technology to reduce labor costs, improve safety through remote monitoring and conserve energy during power transmission.
According to the U.S. Department of Energy in a 2013 Energy Efficiency Study, approximately 50% of Industrial, Commercial and Residential Energy Consumption in the U.S. is attributed to electrical motor driven systems. In industry, the number is closer to 70%. Here we’ll discuss the new generation of motor control.
What’s a Motor Protection Relay, How Does it Work?
Intelligent protective relays detect that a problem is developing by identifying slight deviations in current, voltage, resistance, or temperature. Just as a thermostat regulates the control of an air conditioner or furnace in a home, protective relays help prevent motor overheating, which in addition to damaging the motor, can cause damage upstream and downstream in an electrical power distribution system. Motor controls and their circuits need to be in what electrical professionals refer to as “coordination." Refer to 'Short Circuit Protection and Safety Evaluation'.
Intelligent Relays in Motor Control Centers
Relays are found everywhere in motor control centers, also known as MCC’s, where electrical apparatus like AC and DC drives have significant variances in AC and DC voltages. An MCC can be thought of as a large filing cabinet, or series of interconnected cabinets with drawers. They’re not just full of relays. They also contain circuit breakers, starters, contactors, fuses and other electrical distribution and control products. It’s understandable that this equipment and components need to be coordinated. You will find motor control centers in all types of commercial and industrial settings.
Overcurrent and Overload Relays
Sometimes “short circuit”, “overload” and “overcurrent” are used interchangeably. However, they put different demands on relays and other power gear. Overcurrent and Overload Relays are both designed to prevent motor damage or failure. Electrical professionals deal with overcurrent and overload in different ways using relays. See our feature on short circuit protection or overload protection for an understanding of the basics. Basically, Overcurrent Relays protect against currents exceeding (i.e. over) the acceptable current rating of equipment. They usually operate instantly, breaking the current. A “short circuit” is a type of overcurrent. On the other hand, Overload Relays protect motors from a running, prolonged overcurrent that would cause a motor to overheat, thus the term “overload.”
Intelligent Motor Protection: A Smart Move for Panel Builders
Integrated motor controls with intelligent relays embed all the needed monitoring, calculating and communication in this “smart” relay. This conserves space in electrical panels. This might appeal to panel builders who are looking for ways to save space or add additional features facility managers and electrical contractors may call for. For example, a contractor may be asked to include more breakers, lighting controls and switches in a panel for new construction or system upgrades. This could mean replacing or upgrading with space and energy efficient panelboards to accommodate the specifications.
Find out More:
Count on intelligent relays in electrical motor control to reduce labor costs, improve safety, save energy and space while protecting the “quarterback”. Find out more about how to protect these assets. Contact EECO at 800.993.3326 or email AskEECO@eeco-net.com.
