SIEMENS
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Siemens IK PI · 2015
PROFIBUS
Soft Starters
3RW44 soft starters for High-Feature applications
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Overview
The solid-state SIRIUS 3RW44 soft starters are suitable for the
torque-controlled soft starting and ramp-down as well as braking
of three-phase asynchronous motors.
Optionally, SIRIUS 3RW44 soft starters can be upgraded with a
PROFIBUS DP or PROFINET module. Thanks to their communi-
cation capability and their programmable control inputs and
relay outputs the SIRIUS 3RW44 soft starters can be very easily
and quickly integrated in higher-level controllers.
In addition to soft starting and soft ramp-down, the 3RW44 soft
starters provide numerous functions for higher-level require-
ments. They cover a performance range up to 710 kW (at 400 V)
in the inline circuit and up to 1200 kW (at 400 V) in the inside-
delta circuit.
The 3RW44 soft starters are characterized by a compact design
for space-saving and clearly arranged control cabinet layouts.
For optimized motor starting and stopping the innovative
SIRIUS 3RW44 soft starters are an attractive alternative with
considerable savings potential compared to applications with a
frequency converter. The new torque control and adjustable
current limiting enable the High-Feature soft starters to be
used in nearly every conceivable task. They guarantee the
reliable avoidance of sudden torque applications and current
peaks during motor starting and stopping. This creates savings
potential when calculating the size of the switchgear and when
servicing the machinery installed. Be it for inline circuits or in-
side-delta circuits – the SIRIUS 3RW44 soft starter offers savings
especially in terms of size and equipment costs.
The bypass contacts already integrated in the soft starter
bypass the thyristors after a motor ramp-up is detected. This
results in a further great reduction in the heat loss occurring
during operation of the soft starter at rated value.
Combinations of various starting, operating and ramp-down
possibilities ensure an optimum adaptation to the application-
specific requirements. Operation and commissioning can be
performed with the user-friendly keypad and a menu-prompted,
multi-line graphic display with background lighting. The opti-
mized motor ramp-up and ramp-down can be effected quickly,
easily and reliably by means of just a few settings with a previ-
ously selected language. Four-key operation and plain-text dis-
plays for each menu option guarantee full clarity at every mo-
ment of the parameterization and operation.
Applicable standards
•
IEC 60947-4-2
• UL/CSA
Functionality
Equipped with modern, ergonomic user prompting the 3RW44
soft starters can be commissioned quickly and easily using a
keypad and a menu-prompted, multi-line graphic display with
background lighting. The optimized motor ramp-up and ramp-
down can be effected quickly, easily and reliably by means of
just a few settings with a selectable language. Four-key opera-
tion and plain-text displays for each menu option guarantee full
clarity at every moment of the parameterization and operation.
During operation and when control voltage is applied, the dis-
play field continuously presents measured values and operating
values as well as warnings and fault messages. An external dis-
play and operator module can be connected by means of a con-
nection cable to the soft starter, thus enabling active indications
and the like to be read directly from the control cabinet door.
The SIRIUS 3RW44 soft starters are equipped with optimum
functionality. An integral bypass contact system reduces the
power loss of the soft starter during operation.
This reliably prevents heating of the switchgear environment.
The SIRIUS 3RW44 soft starters have internal device overload
protection. This prevents thermal overloading of the power
section's thyristors, e.g. due to unacceptably high closing
operations.
Wiring outlay for installing an additional motor overload relay is
no longer needed as the SIRIUS 3RW44 soft starters perform
this function too. In addition they offer adjustable trip classes
and a thermistor motor protection function. As an option the
thyristors can also be protected by SITOR semiconductor fuses
from short-circuiting so that the soft starter is still functional after
a short circuit (type of coordination "2"). And even inrush current
peaks are reliably avoided thanks to adjustable current limiting.
In addition a creep speed function is available for positioning
and setting jobs. With this function the motor can be controlled
in both directions of rotation with reduced torque and an adjust-
able low speed.
On the other hand the SIRIUS 3RW44 soft starters offer a new,
combined DC braking function for the fast stopping of driving
loads.
Highlights
•
Soft starting with breakaway pulse, torque control or voltage
ramp, adjustable torque or current limiting as well as any
combination of these, depending on load type
•
Integrated bypass contact system to minimize power loss
•
Various setting options for the starting parameters such as
starting torque, starting voltage, ramp-up and ramp-down
time, and much more in three separate parameter sets
•
Start-up detection
•
Inside-delta circuit for savings in terms of size and equipment
costs
•
Various ramp-down modes selectable: free ramp-down,
torque-controlled pump stop, combined DC braking
•
Solid-state motor overload and intrinsic device protection
•
Thermistor motor protection
•
Keypad with a menu-prompted, multi-line graphic display with
background lighting
•
Interface for communication with the PC for more accurate
setting of the parameters as well as for control and monitoring
•
Simple integration into the motor feeder
•
Simple mounting and commissioning
•
Display of operating states and fault messages
•
Connection to PROFIBUS and PROFINET with optional
PROFIBUS DP or PROFINET module
•
External display and operator module
•
Mains voltages from 200 to 690 V, 50 to 60 Hz
•
Can be used up to 60 °C (derating from 40 °C)
© Siemens AG 2014