AC Numeric Motor Protection Device, Brand Name : Novatek Electro

We offer numeric relay, numeric motor protection device.
The ubz-301 provides: a simple and accurate electromotor nominal current setting by nominal current standard scale; the electromotor operating current setting that differs from standard values; overload tripping with a dependent time delay (the current-time characteristic curve is plotted for a conventionally cold motor). The motor heat balance differential equation is being solved in the operation process. This approach enables to take account of the preceding electromotor status and to make a decision on heat overload presence with the maximum validity. This method also permits to allow for a motor start heating and to restrict (at the customer's option) amount of starts per unit time; shift of current-time characteristic curve along the current-axis and along time-axis as well; setting of trip thresholds for the minimum/the maximum voltage, line voltage & phase current imbalance, and also for automatic reset delay at the personal customer's discretion; fault type indication, the mains voltage presence indication, current range indication the unit is adjusted to, and load energization indication; the data exchange and transfer to the local computer network according to the rs-485 modbus record through the bo-01 exchange unit (bo-01 is supplied on order).
description
the unit is a microprocessor-based digital device that provides a high degree of reliability and accuracy. The unit doesn't need any auxiliary supply because it retrieves it's energy demand out of the measurement signal: it's self-powered by the voltage to be monitored. Simultaneous isolated independent monitoring for the mains voltage and phase currents permits to detect the type of occurring fault and to provide a different decision-making logic for each fault type. When the mains voltage faults occur the unit performs automatic load reset on return voltage parameters to normal operating conditions. If a fault is induced by abnormal condition inside the motor (phase current imbalance at the symmetrical power line voltage, leakage current presence etc.) restart is disabled. In other words it is a numeric motor protection relay.
the unit comes with three toroidal current transducers (ct). Two of them are the phase/line current transducers (ct1, ct2), power phase cables are pulled through them. The third transducer is the differential current transducer (cb ct) that has an enlarged diameter, because three power phase cables are pulled through it.