2 Engineering2.7 Residual current circuit-breaker (RCD)DS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com 372.7 Residual current circuit-breaker (RCD)Residual current circuit-breakers – also referred to as RCDs (residual currentdevices) and ground fault circuit interrupters (GFCIs) – protect people andlivestock from the presence (not the production!) of impermissibly hightouch voltages. They prevent dangerous and fatal injuries caused byelectrical accidents and also serve as fire prevention.Size 1 and 2 soft starters of the DS7 series have no connection to the earthpotential (PE). In size 3 and 4, the DS7 soft starters have an exposed heatsink which must be connected with the earth potential (PE).When using a DS7 soft starter, there is no leakage current at the motorfeeder. Standard residual current circuit breakers (RCD part no. A) up to30 mA can be used.Figure 19: Motor feeder with RCDF1 = Residual current circuit breaker (RCD)F3 = optional semiconductor fuseQ1 = Cable protection + motor protectionQ21 = Soft starterM1 = MotorM3 ~1L12L33L51T22T43T6L1L2L3PEQ1RCDQ21BG1, BG2F1F3M1I > I > I >1L12L33L51T22T43T6BG3, BG4PEPE
