S611 Soft Starter
MN03902011E—May 2012 www.eaton.com
17
Functional Description
Power
The S611 soft starter controls the voltage applied to a
three-phase induction motor in order to control the starting
torque and provide a smooth starting characteristic. Within
the soft starter are three power poles, each of which
includes a set of anti-parallel SCRs (thyristors) in parallel with
a contact. During a start, the conduction periods of the SCRs
are continuously adjusted to apply a gradually increasing
voltage to the motor, resulting in gradually increasing torque
and a smooth start. As the motor reaches its rated speed,
the power pole contacts are closed, bypassing the SCRs for
the most efficient operation.
Line Connected Soft Starter SCRs
For each start, the length of time the SCRs are conducting
current as well as the magnitude of that current determine
how hot the SCRs will get. Between successive starts, the
SCRs must cool down to avoid exceeding their thermal
limits.
Appendix C—Ratings, Cooling and Power Losses
gives the S611’s application ratings for various starting
conditions. Staying within these specified limits should avoid
over temperature trips.
Control
There are four (4) terminal blocks and one (1) connector on
the face of the S611 soft starter that are used for control
circuit functions:
1.
120 Vac supply voltage (TB1)—Soft starter control power
input.
2.
120 Vac control inputs (TB2)—Remote (network) select,
permissive, start, and reset control functions.
3.
Relay contact terminals (TB3)—One (1) Form A relay,
one (1) Form C relay.
4.
Network communications (TB4)—Modbus connection.
5.
Network communications (TB5) (connector)—
Connections to network adapter modules.
Note:
Do not apply 120 Vac to the network communications
terminal block. 120 Vac will permanently destroy the
printed circuit board.
The software contained in the S611 soft starter is the heart
of the product. This software allows you to control nearly
every aspect of the soft starter’s functionality. In this section,
various features and protection options are described.
Note:
You will find a complete listing of these parameters in
Appendix A—Parameters
.
L3
Motor
Three-Phase
AC Line
Voltage
L2
L1
T3
T2
T1
www.comoso.com
Содержание S611
Страница 1: ...S611 Soft Starter User Manual Effective May 2012 Supersedes August 2011 www comoso com...
Страница 2: ...www comoso com...
Страница 12: ...S611 Soft Starter x S611 Soft Starter MN03902011E May 2012 www eaton com www comoso com...
Страница 94: ...82 S611 Soft Starter MN03902011E May 2012 www eaton com www comoso com...
Страница 95: ...www comoso com...