STS 100-800 A

The STS is used as a transfer switch in 3-phase power grids and switches between two power sources
(manually or automatically). So it ensures power supply redundancy of connected devices from 100 to 800A. Break-Before-Make-switching prevents both
power sources being connected simultaneously
to the consumer.

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  • Permanent monitoring of the power sources
  • Break-Before-Make Switching
  • Automatic switching back
  • Manual switching possible
  • 3- or 4-pole versions available
  • Display: kVA, kW, CF, PF, A, V, Hz.
  • Redundant cooling with monitored fans
  • Front access to all power components
  • Neutral with 2 x Inom
  • Interfaces: RS 232, RS 485 (MODBUS protocol)
  • Double maintenance bypass prevents cross connection
  • 24 months warranty


STS100 A250 A400 A630 A800 A
PowerPower230V AC L-N, 400 VAC ph-ph, other voltages on request
Voltage window± 10% (up to ± 20% on request)
Rated current100 A250 A400 A630 A800 A
Rated frequency, Frequency range50/60Hz, ± 2Hz (up to ± 4Hz on request)
Transfer phase angleStandard 10° (5° ÷ 30° on request)
OutputOutput voltageSame as Input
Output frequencySame as Input (50/60 Hz)
Output currentSame as Input
Maximum transfer time 4-15 ms depending on the phase angle
CommunicationDisplayGraphical LCD display, mimic LED panel and keyboard
ConnectionsRS485 (Modbus RTU protocol), Standard: 4 SPDT relays,
optional 6 additional SPDT relays
MechanicDimensions (H x W x D in mm)1475 x 820 x 8351900 x 1220 x 860
Weight in kg265290305615660
Input terminals3-phase hardwired with neutral
Output terminals3-phase hardwired with neutral
Regulations /
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