UBZ unit provides for protection of dual-speed (double-coil) asynchronous induction electric motors of 5 to 50A rated current with use of integrated current transformers.
The UBZ unit provides for electric motor protection in the following cases:
• when the mains voltage is of poor quality (unallowable voltage surges, phase loss and phase/line voltage imbalance, incorrect phase sequence and phase “coincidence”);
• when mechanical overloads (symmetrical phase/line current overload) occur;
• when reverse sequence of the current threshold (current imbalance) occurs;
• when start delay or rotor obstruction;
• when the insulation level between the fixed coil and frame is abnormally low (startup check);
• when stator winding ground-to-fault takes place during operation – ground leak current protection is activated;
• when motor heat overload takes place.
Selection of the protection parameters is defined by the user in course of the device programming. For each separate type of protection, the unit allows to prohibit or allow automatic load reset (AR).
It is equipped with complete set of protections implemented in UBZ-301 version. It additionally provides protection against long lasting start and rotor blockage as well as motor winding overheating monitoring with use of temperature sensors.
Technical Specifications
| Rated supply voltage: three-phase | 380V 50Hz |
| Mains frequency, Hz | 48-62 |
| Rated currents range, A | 5-50 |
| Voltage hysteresis, (phase/line), V | 10/17 |
| Thermal hysteresis, % of accumulated heat at shutdown | 33 |
| Tripping threshold accuracy for current, ≤, % of rated current | 2 |
| Tripping threshold accuracy for voltage, ≤, V | 3 |
| Phase imbalance detection accuracy for voltage, ≤, V | 3 |
| Temperature permission of temperature sensors, °С | 1 |
Minimum operational voltage:
- single-phase voltage power supply when one phase and neutral wires are connected, ≥ V
- three-phase power supply voltage, ≤ , V |
180
450 |
Digital input for signal to switch to higher speed (dry contact).
Analog input to connect differential current transformer (zero sequence transformer).
Three analog inputs to connect external CT (current transformers)*
There are two analog input for connection temperature sensors (type PT100, Ni100, Ni120) | |
Main outputs:
load relay – two groups of changeover contacts (5A, 250V cos φ=1), to control motor starter | |
| Power consumption (under load), ≤, VA | 5.0 |
Enclosure protection degree:
- case
- terminal block |
IP40
IP20 |
| Operating temperature range, °C | from -35 to +55 |
| Storage temperature range, °C | from -45 to +70 |
| Weight, kg, no more than | 0.5 |
| Dimensions - nine S type modules | 85.8 х 156.2 х 56.8 mm |
| Mounting – on a standard 35 mm DIN bar |
| Mounting position – any |
| * - optional |
Characteristics of output terminals of integrated relays
| Operation mode | Max. current for 250 V A.C. | Number of tripping х1000 | Max. switching power | Max. sustained safe voltage | Max. current for U=30 V D.C.(N of tripping) |
|---|
| Power relay |
cosφ = 0.4
cosφ = 1.0 | 2 A
5 A | 100
100 | 1000 VA | 460 V | 3 A (50000) |
| Signal relay |
cosφ = 0.4
cosφ = 1.0 | 5 A
16 A | 100
100 | 4000 VA | 440/300 V | 3 A |
Dimensions
