Eaton DS7 Series, Manual

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2 Engineering
2.11 Motor connection
DS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com
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2.11 Motor connection
DS7 soft starters enable the operation of different variants of three-phase
asynchronous 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, internally
cooled or surface-cooled three-phase asynchronous motor with a speed of
1500 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 starter
in a star or delta circuit – depending on the mains voltage. This type of setup
uses 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) or
motors 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 up
the motor excessively.
Star connection
Delta circuit
Figure 22: Permissible motor connection circuits
(shown for devices up to 32 A, furthermore, phase L2-T2 is connected
through instead of L3-T3)
L1 L3
L1 L3
L2
L2
T1 T2
T3
U1 V1 W1
W2 U2 V2
U1 V1 W1
W2 U2 V2