The UBZ-304 can operate in the mains with isolated neural as well as with solidly-grounded neutral.
The device is equipped with the panel.
The UBZ provides continuous control of the mains voltage parameters and RMS phase (line) currents of the three-phase electric equipment of 380V 50Hz, as well as the electric motor insulation resistance test.
The UBZ provides electric motor protection in the following cases:
• when the mains voltage is of poor quality (unacceptable voltage fluctuations, phase interruption, violation of phase sequence and phase coincidence, phase/line voltage imbalance, decrease of mains frequency below the specified one and (or) increase of mains frequency above the set one);
• when reverse sequence of the current threshold occurs;
• when phase current imbalance (without overload) occurs that is induced by the insulation fault inside the motor and/or the lead cable (comparison of current imbalance factor with voltage imbalance factor based on negative sequence);
• when motor torque is lost (“dry run” for pumps) – protection based on the minimum inrush and/or operating current;
• when start delays or locked rotor occurs;
• when insulation level between the fixed coil (stator) and frame is abnormally low (test before motor start).
• when motor thermal overload occurs;
• when winding overheating occurs (winding temperature is measured by the integrated temperature sensors, or frame temperature is measured by the external temperature sensors).
General specification
| Application of the unit | Switchgear and control-gear;
induction motor protection control |
| Design (installation) type | DIN rail 35 mm |
| Protection rating of front panel | IP64 |
| Protection rating of housing | IP10 |
| Climatic version | NC 3.1 |
| Contamination level | II |
| Overvoltage category | II |
| Rated voltage of insulation | 450 V |
| Rated impulse withstand voltage | 2.5 kV |
| Electric shock protection class | II |
| Wire cross section for connection to terminals | 0.5-2 mm² |
| Torque for terminal screws | 0.4 N*M |
Technical Specifications
| Operating supply voltage, three-phase | 380 V, 50 Hz |
| Mains frequency, Hz | 48-62 |
| Rated current of CT, A | 5 |
| Voltage hysteresis, (phase/line), V | 10/17 |
| Thermal hysteresis, % of accumulated heat at shutdown | 33 |
| Determination accuracy of trip threshold for current, not more, in % of rated value | 2 |
| Determination accuracy of trip threshold for voltage, not more, V | 3 |
| Determination accuracy of out-of-phase voltage, not more, V | 3 |
Voltage when maintaining serviceability:
- phase voltage, when powered by one phase and zero wire is connected, not less, V
- line voltage, when powered by three phases, not more, V |
180
450 |
Main outputs:
- load relay – two groups of changeover contacts to control the electric motor starter – 8A, 250 V at cos φ=1;
- functional relay – one group of changeover contacts - 16A, 250V at cos φ=1 (function of the relay is set by the user). | |
Analog inputs:
- input to connect temperature transmitter (types: Pt100, Ni100, Ni120), pc.;
- input to connect temperature transmitter of PTC-1000 type, pc.;
- three analog inputs for standard CT with 5A output (T-0.66 type or similar), pc.;
- input to connect differential current transformer (zero sequence transformer) pc.;
- input to measure current of 0-20 mA, pc.;
- input to measure voltage of 0–10 V, pc.. |
1
1
3
1
1
1 |
| Permit according to temperature of temperature transmitters, °C | 1 |
| Power consumption (under load), VA, not more | 5.0 |
| Weight, kg, no more than | 0.34 |
| Overall dimensions | 110 х 96 х 88.3 mm |
| Position in space | free |
| Housing material | self-extinguishing plastic |
Characteristics of output terminals of integrated relays
| Operation mode | Max. current at U~250 V | Number of actuations х1000 | Max. switching power | Max. continuous boosting AC / DC voltage | Max. current at Uconst=30 V |
|---|
Functional relay
cosφ = 0.4
cosφ = 1.0 |
5 A
16 A |
100
100 | 4000 VA | 440/300 V | 5 A |
Load relay
cosφ = 0.4
cosφ = 1.0 | 2 A
8 A | 100
100 | 2000 VA | 460 V | 3 A |
Dimensions
