ST-UK 33 from 300 to 600 KVA



Online UPS 300 KVA to 600 KVA 3-Phase Input; 3-Phase Output


ST-UK33 the new transformer-less UPS from SATRON Power Solutions. Best in class system for its compact footprint, the system also provides high efficiency up to 97 % .


ST-UK33 is flexible in its configurations and benefits of a wide range of options. This makes it an ideal power protection for high capacity sized critical applications where power consumption, available space and reliability are key parameters.


the compact footprint and the wide range of options, make ST-UK33 the best solution for the power quality of any critical load.



The UPS is based on a highly efficient transformer-less online , double conversion technology, ensuring the lowest OPEX on the market in its category. Best in class for energy consumption; the system has a very low Total Cost of Ownership (TCO).


  • DSP, fully digital control technology
  • 3-level IGBT technology
  • Transformer-less architecture
  • AC/AC efficiency up to 97%
  • Input PF > 0.99 and THDi< 3 %
  • Output PF up to unity (without derating)
  • Up to 8 units in parallel connection
  • Static and maintenance bypass switches included
  • Back-feed protection included
  • Touch screen display


  • Easy installation, operation and maintenance: all models have front access, for easy maintenance or inspection.
  • Maximized savings in terms of footprint (m2), power installed (kVA), electrical system (cabling and protection devices), security (MTTR and MTBF) and power management (kW and cost).
  • Easy upgradeable architecture with reduced CAPEX and optimized OPEX. ST-UK33 offers a low input THDi and almost unity input PF, even when a low percentage of load is applied: no additional power-consuming filter.
  • Wide range of options such as a load synchronization tool, top cable entry, up to IP41 protection degree, battery temperature probes as well as all connectivity devices (SNMP, Modbus, RS232).
  • Touch screen display: all the main parameters of the UPS are always under control.
  • International top-class brands of major components redundant design for critical circuits
  • Dual system control card and dual bypass unit power prevent single failure point
  • Large allowance for power module, strong protection for overload and short circuit.
  • Strengthen PCBs coating: Anti-salt spray, anti-corrosion, anti- moisture, anti-dust, etc.




  • High efficiency in online mode (>97%) reduces heat dissipation and limits

power consumption costs .


  • Efficiency>99% in ECO mode gives significant cost reduction .


  • THDi ≤3% .


  • Self-aging function, easy debugging and test on site, reduce power loss.


User-friendly Interface

  • User-friendly operation design to avoid false operation


  • Large-size touch screen with LED indicators, comprehensive and visualized information display


  • Large data storage capacity,10000pcs events logs


  • Friendly human-machine interface with data and graphical forms


Intelligent Management

  • Multiple communication interface supports UPS and load intelligent monitoring


  • Intelligent SNMP achieves local monitoring and remote monitoring


  • Batter y temperature compensation function improve the battery performance

and extend battery use life


  • Intelligent fan control according the load capacity reduces the noise

and prolongs fan service life


  • Fault trace management for convenient failure analysis

(100ms waveform record before & after fault point)


Technical Specifications

MODEL ST-UK33-300 ST-UK33-400 ST-UK33-500 ST-UK33-600
Power Ratings ( KW ) 300 400 500 600
Input Voltage 380/400/415 VAC , 3 Ph + N + G
Voltage range without battery mode -25% / +20%
Frequency ( Auto Selection ) 40 ~ 70 HZ (auto-sensing )
Power Factor ≥ 0.99
THDi < 3% ( with full linear load )
Output Voltage L-N 220/230/240 ±1% , L-L 380/400/415 ±1%
Frequency ( Hz ) 50/60 Hz ± 0.1 ( Battery Mode )
Slew Rate ( HZ / S ) 0.5 to 5 ( adjustable )
Power Factor 1
THDv THD < 1% ( Linear Load )  ,  < 4% ( Nonlinear Load )
Voltage Waveform Pure Sine Wave
Transfer Time < 20 ms ( Without Interruption )
Efficiency ( AC/AC VFI mode ) Up to 97%
Overload 130 % for 10 Min. , 150 % for 1 Min.
Crest Factor 3 : 1
Short Circuit Response Short circuit proof ( 1.8 x IN for 180 ms ) , if continuous UPS will shutdown
Type Sealed Lead Acid maintenance – free .
Voltage ( VDC ) 384 to 528 VDC ( from 32 to 44 blocks 12 V )
Charger Current ( A ) Max. 20 – 100 A
Battery Management Exhaustive discharge protection / Protection against excess load Automatic battery test (daily, weekly, monthly)
Communication Interface (Dry contact ,MODBUS and SNMP optional)
User interface / failure indication 3 LED’s with traffic light display, detailed indication via LCD display (acoustic/visual) (alarms: at mains failure, overload, battery charging, battery replacement, fan fault data logger – with clear text display incl. Date and time history)
Protection Low battery, overload, short-circuit and over temperature
Alarms Low battery, abnormal AC input, UPS failure
Audible Noise ( 1 m distance ) < 75
Operation Temperature -5 to 40 ºC
Relative Humidity 0 to 95% No Condensation
Operation Altitude Up to 1000 m @ nominal load
Dimension ( WxDxH ) mm 1400x800x1800 1400x800x1800 1600x800x1800 1400x900x1800
Weight ( Kg ) 950 1000 1200 1300