Software: UBZ-302-01 Control Panel (elevator) – download the program

The universal protection unit for asynchronous motors UBZ-302-01 is designed for protecting two-speed (dual-winding) motors, continuously monitoring network voltage parameters, actual phase/line currents, and checking insulation resistance of electric motors.

UBZ provides protection for asynchronous two-speed (dual-winding) motors with nominal currents from 5 to 50A when using built-in current transformers.

UBZ provides protection for motors in the case of:

• poor network voltage (unacceptable voltage spikes, phase loss and imbalance, phase sequencing and sticking violations);
• mechanical overloads (symmetrical overloads on phase/line currents);
• exceeding the reverse sequence current threshold (current imbalance);
• extended motor start or rotor blocking;
• unacceptably low insulation level between the stator and motor body (pre-check before start-up);
• stator winding “earth” fault during operation – protection against “earth” leakage currents;
• thermal overload of the motor.

The set of specific protection parameters is defined by the user through device programming. For each type of protection, automatic reset (AR) of the load can be enabled or disabled.

It includes a full set of protections implemented in UBZ-301. Additionally, it provides protection against extended start and rotor blocking, and monitors motor winding overheating using temperature sensors.