Plastic AC UBZ-304 Numeric LT Motors Protection Relay, Color : Black

UBZ-304 Numeric electric motor protection device is designed for protection of asynchronous LT motors having power of 2.5 to 315 kW (5A – 630A), with use of external standard current transformers having output current of 5 amperes (secondary), works in power mains with isolated neural or with solidly grounded neutral terminals.

The device provides continuous monitoring of the mains voltage parameters and RMS phase/line currents of the three-phase electric equipment of 380V-415V 50Hz, as well as for the motor insulation resistance test. More than 90 parameters can be programmed/customised depending on application & usage with variable trip delay and auto-reset delays. Four line full function backlit LCD display provides all information and eases programming from front panel. Built In RS-232 & RS-485 Modbus communication for DCS/ SCADA integration, realtime monitoring, programming and remote control. Device comes with free PC software for realtime monitoring & programming. Universally accepted flush mounted 96 x 96 x 78.3mm overall dimensions.

UBZ performs the following protection types for electric motors:

• over-current protection in phases;
• ground fault protection (zero-sequence current);
• phase current asymmetry (negative-sequence current);
• for exceeding negative-sequence current factor to negative-sequence voltage factor;
• thermal overload;
• undercurrent protection in phases (dry-run);
• delayed starting (rotor blocking);
• overheating of windings (RTD inputs);
• minimum line voltage;
• maximum line voltage;
• line voltage imbalance (negative sequence voltage protection);
• improper phase sequence;
• decreasing of mains frequency lower that setting;
• for increasing of mains frequency higher that setting;
• minimum insulation resistance of the motor winding;
• motor phase loss (protection is operated when the motor current is disabled in one (two) phase).