Eaton Industrial Switchgear - xStart switching, protections and actuating motors

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2010 CA08103002Z-EN
9/18 DS7 soft starters
Functions
Typical applications for DS7 soft
starter series are:
• Pump drives: soft starting three-
phase motors prevents fluid
hammers. The mechanical load on
the entire system is decreased,
increasing its durability.
• Fan drives: soft starting keeps fan
belts from slipping, preventing
premature wear. This lowers
operating costs and extends the
system's lifespan.
• Conveyor belts: conveyor belts start
running smoothly, instead of starting
with a jolt. This ensures that any
goods being conveyed do not topple
over. Mechanical damage to the
belt itself is avoided, making it more
durable.
Documentation
Surface mounting and standard
mounting procedures are described
in the corresponding installation
instructions and in the manual.
Installation instructions
Instructional leaflet 8250-2541: For
devices with frame size 1 (up to 12 A
motor rating)
Instructional leaflet 8250-2542: For
devices with frame size 2 (up to 32 A
motor rating)
Instructional leaflet 8250-2543: For
devices with frame sizes 3 and 4 (up to
200 A motor rating)
Manual
AWB 8250-1634
You can download the documentation
for the DS7 soft starters from the
Internet:
Description
Application
DS7 soft starter series are two-phase
controlled soft starters used to soft
start applications with a normal
operating frequency and a rating
range from 3 to 200 A (1.1 to 110 kW
with a 400 V line voltage).
StartingtransientsandDCcomponents
during startup are effectively sup-
pressed and guarantee even motor
starting.
The special actuation method
(asymmetric trigger control) used for
the soft start function prevents DC
components (Moeller patent) that
would otherwise normally be produced
with two-phase controlled soft starters.
This eliminates the formation of an
elliptical rotary field that would cause
the motor to accelerate in a non-
uniformmanner and lengthen its run-up
time unnecessarily, making the
smooth-running behavior of a DS7 soft
starter comparable to that of a three-
phase controlled soft starter.
Features
• The ramp time can be adjusted
within a range of 1 to 30 s (for
starting) or 0 to 30 s (for stopping)
with a potentiometer.
• The start voltage (or start torque)
can be adjusted within a range of
30 to 100 percent of the line voltage
with a potentiometer.
• Significant reduction in switch-on
current, achieved with a short soft
start ramp time (min. 1 s) for lamp
and heating loads.
• Internal bypass relay in DS7-340
models: switches on automatically
after the end of the ramp, bypassing
the internal thyristors.
• This makes it possible to comply
with radio interference level B
without any additional measures.
• The motor's thermal load is smaller
than it would be without asymmetric
trigger control.
• Designed specifically for long
cables.
DS7