Explore the technical solutions for shutdowns caused by voltage fluctuations during continuous operations in the petrochemical industry.

Thread Content

MRR Low-Voltage Motor Restart Controller – Product Overview: In industrial production, many important low-voltage motors often come to a stop due to \"voltage fluctuations\" (phenomena caused by lightning strikes, short circuits, or other reasons that result in brief drops in voltage or interruptions in power supply; this is commonly referred to as \"voltage fluctuations\"). Such incidents disrupt the continuous production process and cause significant losses for enterprises. The MRR-C series of products was specifically developed to help industrial enterprises avoid shutdowns caused by power fluctuations. The MRR-C series of products incorporate advanced foreign technologies, and feature high reliability, compact size, easy installation, and simple wiring; they can be directly installed in on-site low-voltage switchgear. The MRR-C series of products monitors the grid voltage and the operating status of motors in real time. When a motor in operation stops due to voltage fluctuations in the grid, if the grid voltage returns to normal within an allowable time frame, the motor will start again at a pre-set restart time, thereby resuming operation of the motor that stopped as a result of those voltage fluctuations. If the grid voltage does not return to normal within the allowed time, the controller locks out the program and stops starting the equipment. If there are multiple motors at the site that need to be restarted in batches, setting different restart times for the MRR-C will enable batch restarts. The MRR-C series of products can be used for motor restart under the control of conventional AC contactors, in star-delta starting circuits or reduced-voltage starting circuits, for motor restart controlled by mechanical switches such as the DW series, and for motor restart controlled by frequency converters or soft starters. Functional features: • High-precision timing for accurate restarts • Restoration voltage value can be set to ensure safe restarts • Function for tracking the total operating time of the motor • Comprehensive event logging capability • Real-time display of the motor’s operating status and current voltage value • RS-485 communication for remote control and network-based management • Communication speed can be set (4800, 9600, 19200) • MODBUS protocol • Maintenance-free design, high reliability, and strong resistance to interference

Technical specifications: • Allowable time during voltage fluctuations AF: 0.1 to 999.9 seconds • Restart time for the main relay dA: 0 to 25.5 seconds • Restart time for auxiliary relays db: 0 to 25.5 seconds • Low-voltage setting value UF: 65% to 90% of Ue • Restoration voltage setting value UH: 80% to 100% of Ue • Time adjustment step: 0.1 seconds • Voltage adjustment step: 1V • Voltage detection accuracy: 0.5% • Range for cumulative operating time HC: 0 to 9999 days • Contact rating of the main relay: 10A/250VAC • Contact rating of auxiliary relays: 5A/240VAC, 3A/30VDC • Operating temperature range: -20°C to +60°C • Storage temperature range: -55°C to +85°C • Dimensions: 70mm × 38mm × 105mm

Product diagram: Product selection table: Application areas: • Oil drilling • Petrochemical industry • Metallurgy • Coal mining • Fine chemicals • Light industry • Power generation • Municipal water supply and drainage • Electronics • Biopharmaceuticals • Rubber industry • Wastewater treatment

Images: