Eaton DS7 Manual page 34

1 Device series DS7
1.14 Function
30
DS7 Soft starter 09/16 MN03901001Z-EN www.eaton.com
The soft starters of the DS7 device series are two-phase controlled and are
available in two variants in the power section (for size 1 and 2 or size 3 and 4).
1L1 3L2
2T1 4T2
M
3 ~
Size 1 (4 to 12 A)
Figure 15: Designs and variants in the power section
￫
In the case of conventional two-phase controlled soft starters,
the physical conditions involved in their operation lead to DC
components that in turn result in an elliptical rotating field being
produced. This causes the motor to start up unevenly and the
acceleration time is unnecessarily extended.
The asymmetrical thyristor trigger control that was developed and patented
by Eaton (Moeller) for phase control (PCT/EP00/12938, 19.12.2000) prevents
DC components and ensures optimum startup behavior. This control is
integrated in the DS7 soft starters and is active during the start (t-Start) and
stop ramp (t-Stop).
5L3
6T3
Size 2 (16 to 32 A)
1L1 3L2 5L3 PE
2T1 4T2 6T3 PE
M
3 ~
Size 3 and 4 (41 to 200 A)