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Made in Switzerland

Transfer switch US-TFSI to IBS Inverter:

In modern electrical installations in vehicles, personal safety is important. This safety is achieved with the US-TSFI transfer switch with 4-wire 30mA fault current protection. The various UltraSine inverters from 150W to 1600W are available for the 230V power supply. In addition, a land connection is increasingly being used via the external supply in order to feed all 230V consumers in the vehicle when the mains supply is present and, at the same time, to charge the battery (s) when the charger is installed. The US TSFI automatically takes over all the switching functions and guarantees the best possible protection with the 4-wire FI switch. The IBS Transfer switch offers the best possible protection against unwanted electric shock even in the case of insufficient fault current protection of the shore connection.

Technical specifications

  USi Transfer switch
inputs 2
Inputs for US inverters 1
Inputs for land network 1
outputs 2
Outputs connected 1
Outputs directly 1 (charger, direct land connection)
Outputs FI protected 1 (switched output)
Voltage 230V/50Hz
Max. Current permanent / on 10A / 20A
Ambient temperature -25°C…+60°C
Switched signals Neutral (N), phase (P)
Earth switched No
Possibility to switch earth yes (Request to IBS)
FI switch integrated yes
Switching relay integrated yes
Dimensions lxbxh (without feet) 175x168x82mm
Weight 1.4kg
  FI-Schalter (integrated)
Fault current tripping 30mA
release characteristic Type A
  Relay (integrated))
Response / release time 9ms /3ms
relay protection type RT I


Technology Switch relay with priority FI switch
Housing Aluminum and plastic, IP40


EMC Directive: 2004/108/EC
  -EN 61000-6-3:2006
  -EN 61000-6-1:2005
RoHS directive: 2002/95/EC
FI switches: EN 61008-1
  IEC 61008-1
  EN 61008-2-1
  IEC 61008-2-1
Relay: EN 61810-5 (3,6 kV/2)

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USi Transfer switch
LED Signal will show the connected input
US-TSFI schematic complete