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Semidan Power 920 Uninterruptible Power Supply (UPS)

Semidan Power, SP 920 UPS systems, are available from 5 to 30 kVA with single or three phase output. All parts are accessible from the front of the cabinet.

The UPS consists of a charger, battery, inverter and static or electromechanical switch with by-pass possibility.

  • Uninterruptible operation
  • Constant output voltage and frequency with a high efficiency
  • Easy accessible configuration for maintenance
  • Maintenance-free and technical proven design
  • High reliability and long life-time

The battery type is chosen according to application or costumers requirements. In the event of mains failure the inverter will be supplied from the battery. Duration of discharge is in accordance with costumer specification.

Typical applications
  • Data centers
  • Power stations
  • Banks
  • Insurance offices
  • Ship yards
  • Ships
  • Rader and broadcasting stations
  • Hospitals
  • Off-shore platforms
  • Airports
  • Communication systems
  • Process control systems
  • Theatres
  • Cinemas

The internal static or electromechanical switch will, in case of an inverter failure, supply the load through the alternative mains. This increases the up-time considerably. Principally there are two types of switches available:

  1. static switch (No-break)
  2. electro-mechanical switch (Short break, typically 50-100 ms)
  • Thyristor or switch-mode controlled charger
  • Natural or forced cooling
  • Input voltage according to customer specification ±15%, three phase
  • Frequency 50/60 Hz ±5%
  • Output voltage 24/48/110/220/400 Vdc ±0.5%
  • Charging characteristics IU better the DIN 41773
  • Ambient temperature -20 C, max +45 C
  • Relative humidity max 95%
  • RFI N to VDE 0875, BS 800, CE-marking
  • Acoustic noise max 50 dB (A) to DIN 45632

The charger is designed to charge the battery and simultaneously supply the DC to the inverter.


The DC-voltage from the charger or battery is converted into a pulse wave with a constant frequency. The subsequent transformer with L-C-filter produces a constant sine wave output.

  • Natural or forced cooling
  • Input voltage 24/48/110/220/400 Vdc +20% – 12.5%
  • Output voltage according to customers specification, single or three phase
  • Stability of output voltage static ±1% with load between 0-100% throughout the DC-voltage range
  • Power factor 0.8 inductive to 1
  • Overload capability 50% in 30 seconds as standard
  • Pure sinus wave form
  • Frequency 50 Hz or 60Hz ±0.5% (selectable via internal switch)
  • Distortion <=3%
  • Short circuit characteristic the equipment has built-in current limit
  • Ambient temperature -20 C to max +45 C
  • Relative humidity max 95%
  • RFI N to VDE 0875, BS 800, CE-marking
Static switch
  • Thyristor controlled “Make before break”
  • Transfer Zero break
  • Overload capability 10 time rated current for 1 second
  • Acoustic noise Max 60 dB (A) to DIN 45632