RNPP-311M is designed for:

• Monitoring acceptable voltage levels.
• Checking the correct phase sequence and absence of phase sticking.
• Ensuring phase continuity and voltage symmetry in the network (phase imbalance).
• Disconnecting the load during poor network voltage conditions.
• Monitoring the network voltage after load disconnection and automatically reconnecting it once the voltage parameters are restored.
• Indicating fault conditions and displaying voltage availability on each phase.
• RNPP-311M monitors the neutral indirectly.
• The device allows parameter adjustments (voltage trip thresholds, automatic restart delay (AR), and protection trip delay), network voltage selection (400 V or 415 V), and the configuration of protective functions.
• After restoring network voltage parameters, the relay automatically reconnects the load after the set AR delay.

RNPP-311M can operate in the following modes:

• Minimum/Maximum Voltage Monitoring.
• Minimum Voltage Monitoring.
• Maximum Voltage Monitoring.
• Phase Availability Monitoring.
• Monitoring for incorrect phase sequence and phase sticking.
• Phase Imbalance Monitoring.

Phase Availability Monitoring remains active in all operating modes. In any mode, the device trips if a phase is lost or the voltage drops below 100 V on one or more phases for a fixed duration of 0.2 seconds.

Output and Contacts

The device has two groups of independent changeover contacts (1-2-3, 4-5-6). In the "COLD STATE" (device unpowered or not connected), contacts 1-2 (4-5) are closed, while contacts 2-3 (5-6) are open.

When the load relay trips, the load is disconnected by breaking the power circuit of the magnetic starter coil via contacts 1-2 (4-5). Exception: in the "Maximum Voltage Monitoring" mode, the relay operates with reverse switching logic.

Advantages:

• Simple configuration.
• Connection via a magnetic starter.
• Compact size.
• Changeover contacts for versatile use.

Applications:

• Monitoring phase and line-to-line voltages in three-phase networks.
• Protecting three-phase or, in some cases, single-phase equipment from faults, such as voltage anomalies, incorrect phase sequence, phase sticking, phase loss, and voltage asymmetry.
• Ideal for protecting refrigeration and ventilation systems.

Key Features:

• Monitoring allowable voltage levels.
• Phase sequence monitoring and prevention of phase sticking.
• Ensuring phase continuity and voltage symmetry.
• Disconnecting the load by breaking the power circuit of the magnetic starter coil under fault conditions.
• Monitoring network voltage quality after load disconnection and automatically reconnecting the load once voltage parameters are restored.
• Ability to disable specific protective functions.