2 Engineering2.11 Motor connectionDS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com 412.11 Motor connectionDS7 soft starters enable the operation of different variants of three-phaseasynchronous motors:• Standard three-phase asynchronous motor,• Pole-changing motors (Dahlander motors),• Slipring rotor motors,• External rotor motors (fan motors, roller drives),Within this context, a “standard motor” refers to a four-pole, internallycooled or surface-cooled three-phase asynchronous motor with a speed of1500 rpm at 50 Hz or 1800 rpm at 60 Hz.2.11.1 Connection configurations (star/delta configuration)A three-phase asynchronous motor can be connected to the DS7 soft starterin a star or delta circuit – depending on the mains voltage. This type of setupuses a standard connection configuration, also referred to as outside-the-delta wiring (with three connection cables).In a 3 × 400 V supply system, the following motors are generally operated:• up to approx. 4 kW motor output can be switched in a star connection(230/400 V),• over 4 kW motor output in a delta circuit (400/690 V).Do not connect three-phase motors with starpoint-earthing (star circuit) ormotors with a neutral conductor connection to DS7 soft starters (see fig. 23),as one phase is always connected directly to mains voltage and will heat upthe motor excessively.Star connectionDelta circuitFigure 22: Permissible motor connection circuits(shown for devices up to 32 A, furthermore, phase L2-T2 is connectedthrough instead of L3-T3)L1 L3L1 L3L2L2T1 T2 T3U1 V1 W1W2 U2 V2U1 V1 W1W2 U2 V2
