Novatek UBZ-302 Protection Relay 1 Output

The Novatek UBZ-302 is a microprocessor-based digital device that provides protection for 3-phase motors. No external power supply is required as the unit uses the same power supply as the motor. It has been designed to work in 3-phase electric circuits with or without an isolated neutral connection, allowing operation in both in 3 and 4 wire circuits.

The UBZ-302 has 3 built-in current measurement transformers through which the motor power supply wires are looped for continuous current monitoring. In addition, it continuously monitors the power supply voltage, phase/line currents and the leakage resistance of the motor coils.

The UBZ-302 can protect electric motors with rated power from 2.5 to 30kW using its built-in current transformers. With the use of externally connected current transformers (not included) it can protect motors with a rated power of up to 315kW.

• Protects from voltage surges, fluctuations, phase loss, wrong phase sequence, phase imbalance and phase coincidence
• Mechanical overloads (symmetrical overload in phase/line currents)
• Exceeding the threshold for reverse current sequence
• Non-symmetry of the phase currents
• Minimum starting current protects against loss of drive torque (dry stroke for pumps)
• Minimal operation current protects against long lasting motor start or jammed rotor
• Checks insulation between the stator and motor case before motor start
• Earth leakage protection of stator coils during the motor operation
• Thermal overload and overheating protection
• Novatek type UBZ-302