DS7 Series soft start controller

Compact design, high functionality for soft starting applications

With a focus on small size and ease of installation, the
Eaton DS7 line of reduced-voltage solid-state soft start
controllers is designed to meet your needs for reliable and
efficient soft starting. Designed to control the acceleration
and deceleration of three-phase motors, the DS7 Series is
available for current ranges from 4 to 32 amperes.

Features and benefits
• Run bypass mode greatly reduces internal heating created by the power dissipation across the SCRs
and directly connects the motor to the line, improving system efficiency
• Less heat minimizes enclosure size and cooling requirements, and maximizes the life of all
devices in the enclosure
• LED displays device status and provides fault indication
• Variable ramp times and voltage control (torque control) settings provide unlimited starting
configurations for flexibility
• Soft stop control suits applications where an abrupt stop of the load is not acceptable; soft
acceleration and deceleration reduces wear on belts, gears, chains, clutches, shafts and bearings (refer to the graph and dials on the right)
• Minimizes the peak inrush current stress on the power system; peak starting torque
can be managed to diminis mechanical system wear and damage
• 120/230 Vac control voltage; 24 Vac/dc control voltage is also available for personnel
and equipment safety
• Auxiliary relays indicate status of the soft start controllers; the TOR relay is active until motor
stop command is received and/or the soft start controller detects a fault condition, and
the RUN relay is active during the start ramp, bypass and stop ramp

• The simple addition of an overload relay—the Eaton C440, XTOB or XTOE—gives the DS7
soft start controller overload protection, while limited control wiring makes installation quick
and easy
• Seamless integration with Eaton manual motor protectors (MMP) (see large image to the right)
giving the DS7 Series overload and line interruption capability
• Installation of the optional cooling fan increases the thermal operating range of the
unit, even when an MMP is attached. Installation is quick and simple while bringing
additional cooling to the SCRs to enhance service life and reliability (refer to the two
pictures on the right)
• The DS7 Series has enhanced protection capability that includes detecting improper
mains connection, improper motor connection, SCR fault, heat sink/under temperature,
bypass engagement faults, over temperature warning and more.