RNPP-311.1 voltage, phase imbalance and sequence relay is designed to protect three-phase consumers from key electrical network faults, including:

• Unacceptable voltage fluctuations in the network lasting at least 0.02 seconds.
• Voltage asymmetry in the network (phase imbalance).
• Phase loss, incorrect phase sequence, and phase sticking.
• RNPP-311.1 measures the actual values of phase (line-to-line) voltages and controls the coil of an external magnetic starter, which switches the load power circuit.
• It indicates voltage faults and the state of the load relay (on/off).
• The relay continuously monitors the voltages in a three-phase network, comparing them with user-defined thresholds using the regulator Unom ±%.
• The device disconnects the load if the voltage exceeds the user-defined limits.

RNPP-311.1 has a single adjustable trip setting for both maximum and minimum voltage. For example, in the 10% position, the relay trips when the voltage rises or falls by 10% of the nominal value.

RNPP-311.1 can operate in the following states:

Normal Operation:

• The network voltage remains within the limits set by the user during configuration.
• The automatic restart delay (AR) has elapsed.
• The protected equipment is connected to the network.
• The "ALARM" indicator is off.
• The "LINE" indicators are lit.
• Voltage Fault.
• The network voltage exceeds the user-defined limits for longer than the time specified in the technical specifications.
• The protected equipment is disconnected from the network, and the "ALARM" indicator is lit.
• If a phase is lost, the corresponding "LINE" indicator is off.
• AR Delay.

The AR delay begins counting down after power is applied or a fault occurs. When the delay expires, the device returns to the Normal Operation state if the network voltage parameters have been restored.

Advantages:

• Easy configuration.
• Connection via magnetic starter.
• Compact size.
• Changeover contact.

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 sequencing, phase sticking, phase failure, and voltage asymmetry.
• Ideal for protecting refrigeration and ventilation systems.

Key Features:

• Monitoring acceptable levels of actual phase/line-to-line voltage.
• Phase sequence monitoring and prevention of phase sticking.
• Phase continuity and network voltage symmetry control.
• Monitoring the state of magnetic starter power contacts before and after load activation.
• Load disconnection by breaking the power circuit of the magnetic starter coil under fault conditions, with user-defined trip delay.
• Monitoring network voltage quality after load disconnection and automatic reconnection once voltage parameters are restored, with user-defined automatic restart time.
• Visual indication of all types of network voltage faults and failure to switch magnetic starter power contacts.