Eaton’s DS7 soft starters designed to deliver more torque, less vibration

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Soft starters in the new DS7 range from Eaton’s Electrical Sector are designed to combine smooth starting and freedom from vibration, previously only available from three-phase units, with the economy and space savings of a two-phase soft starter. In addition, as fully integrated elements of the Eaton xStart motor control range, they are built to offer the convenience of fast, simple tool-free connection with motor protection relays and circuit breakers.

DS7 soft starters, which are available with ratings from 1.1kW to 15kW on 400V three-phase supplies, feature a patented asymmetric triggering system designed to eliminate DC components in the supply to the motor during starting to ensure smooth starting, allow the units to deliver more starting torque and reduce motor heating. The low level of motor vibration during starting also helps minimize wear on mechanical components, extending their lives and reducing maintenance requirements.

The new soft starters are designed to simply clip together with PKZ and PKE motor protection devices to produce complete starter assemblies; no additional wiring is needed for the power circuits, which not only saves time but also eliminates the possibility of wiring errors. Accessory connectors also are available to provide plug-and-socket connections between motor and the DS7 soft starter; when these are used, conventional motor terminals no longer are needed in the control panel.

Soft starters in the DS7 range are 42mm wide, the same as xStart motor protection devices, and therefore occupy little space in the control panel. As supplied, they are rated for up to 10 starts per hour, each with a starting current of three times full load for a maximum of five seconds. More arduous duties can be accommodated by adding an optional cassette fan that slips into place within the starter without affecting its overall dimensions.

DS7 soft starters can be supplied for use with 24 V AC/DC or 110/230 V AC control circuits. A SmartWire Darwin interface to help minimize control wiring, facilitate remote monitoring and allow easy interfacing with fieldbus systems will be available in the near future.