PR 240 Intelligent Motor Management Relay
PR 240 intelligent motor management relay is suitable for protecting, monitoring, metering, and controlling motors in industrial areas such as
Technology of Electrical Automatic
Keep Your VFDs Running
Your VFDs save energy. Don’t let nuisance trips and hidden electrical faults stop your line. Get protection built for VFDs—stay online, stay safe, keep running.
Explore Our Product Offerings for VFD Applications
We offer a complete protection portfolio for VFD applications: ground-fault protection relays that prevent nuisance tripping and detect low-level ground faults; motor protection relays that protect motors in both VFD and bypass modes; arc flash protection relays for fast fault clearing that safeguard personnel and equipment; and insulation monitoring devices (IMDs) for ungrounded (IT) networks—and more.
Stable Earth Leakage Protection for VFDs
VFDs are widely used in industrial Motor Control Centers (MCCs) to control conveyors, crushers, and pumps. High-frequency leakage current can trip standard ground-fault protection. Built-in drive protection also misses low-level ground faults. So use Type B ground-fault relays designed for VFDs — they detect AC and DC leakage and filter out high frequencies. With multiple VFDs, install one relay per motor circuit or MCC section. A CT at the VFD input protects the drive itself. One on the load side protects the motor and its cables.
Enhance VFD Protection With Motor Management Relay
Built-in motor protection in variable frequency drives (VFDs) has limitations. Thermal models lose accuracy at low frequencies. Protection is disabled in bypass (direct-on-line) mode. And when multiple motors share one VFD, they cannot be protected individually. So an independent motor protection relay is needed to cover overload and locked rotor in both VFD and bypass modes. Short circuits in the Motor Control Center (MCC) can also cause arc flashes, so an arc flash protection relay is required for fast fault clearing.
Insulation monitoring for VFDs
VFDs are widely used in ungrounded power networks (IT systems). Common industries include mining, marine, energy, oil and gas, and water utilities, with typical applications such as pumping, hoisting, propulsion, and HVAC. When the neutral point is ungrounded—on a standalone VFD or across multiple VFDs in a large network—an ungrounded system forms. A single-point ground fault there does not trip or disconnect immediately, posing a safety risk. Insulation Monitoring Devices (IMDs) are designed for these systems. They monitor insulation faults upstream, downstream, and inside the VFD in real time, without affecting VFD performance.
Reliable Solutions for Various VFDs
Tailored monitoring, control, and protection solutions for diverse VFD application scenarios. Our solutions effectively detect electrical faults, safeguarding variable frequency drive against unexpected downtime.
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