7 Connection examples7.3 Size 3 and 4 (41 – 200 A)DS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com 1397.3.7 Bypass circuit for emergency operationIn pump applications the bypass circuit is often required to provide emergencyoperation capability. A service switch (key switch) is used to select the bypasscircuit between soft starter operation and DOL starter operation. This is used tofully isolate the soft starter.In this case, it is important that the output circuit is not opened during operation.The interlocks in the controller ensure that a switchover is only possible after astop.Figure 109: Actuation with bypass emergency operation – pump operationThe electrical and/or mechanical interlocking of contactors Q22 and Q31 ensuressafe operating states.￫ Devices of the DS7-34… series are equipped with integratedbypass contacts. External bypass contacts are therefore notrequired for standard operation.￫ Unlike the simple bypass operation, in this case the bypasscontactor must be designed in accordance with utilizationcategory AC-3. For a suitable contactor, see our recommendedmains contactor in the Appendix (￫ page 221).a Enableb Automatic operation (soft starter)c Manual/bypass operationd Soft starter/Soft stope Bypass contactorS1 = Operating mode selector switchesS2 = OffS3 = OnS4 = Stop (Soft starter)S5 = Start (Soft starter)A1A2K5S5 K5 K5S41314K4 Q22TOR K2Q31 Q11K3 K4K3ENA2Q21K1S3 K1K1 K2S2K2K1K4K3S1K2Q22Q312324RUNQ21Q21d ecbaL00/L-L01/L+
