RNPP-301 Three-phase voltage and phase monitoring relay
The RNPP-301 voltage monitoring relay is designed for protection of three-phase loads against major type of mains faults, as:
- RMS voltage reaching beyond admissible thresholds;
- phase sequence order violation and phase coincidence;
- violation of the mains voltage phase completeness and symmetry.
The device performs monitoring the main circuit parameters and de-energizes load when the parameters fall beyond specified boundaries. The relay also tracks the status of magnetic starter power contacts at no-load and under load while monitoring their operability (burning or sticking).
The front panel LEDs display the following:
- presence of voltage in the mains;
- load status (ON/OFF);
- type of fault.
Six variable pot knobs on the front panel allow for setting:
- the maximum allowable voltage tripping threshold;
- the minimum allowable voltage tripping threshold;
- allowable phase imbalance threshold;
- tripping time delay for load de-energizing in case of emergency voltage reduction;
- tripping time delay for load de-energizing in case of other circuit faults;
- time delay for load re-energizing after the circuit parameters recovery.
The device can function a phase- or line- voltage monitor (user-selected).
Three modifications of this device are currently produced.