AC Motor-Control
Power distribution systems used in large commercial and
industrial applications can be complex. Power may be
distributed through switchgear, switchboards, transformers,
and panelboards. Power distributed throughout a commercial
or industrial application is used for a variety of applications such
as heating, cooling, lighting, and motor-driven machinery. Unlike
other types of power distribution equipment, which are used
with a variety of load types, motor control centers primarily
control the distribution of power to electric motors.
industrial applications can be complex. Power may be
distributed through switchgear, switchboards, transformers,
and panelboards. Power distributed throughout a commercial
or industrial application is used for a variety of applications such
as heating, cooling, lighting, and motor-driven machinery. Unlike
other types of power distribution equipment, which are used
with a variety of load types, motor control centers primarily
control the distribution of power to electric motors.
Wherever motors are used, they must be controlled. In Basics
of Control Components you learned how various control
products are used to control the operation of motors. The most
basic type of AC motor control, for example, involves turning
the motor on and off. This is often accomplished using a motor
starter made up of a contactor and an overload relay.
The contactor’s contacts are closed to start the motor
and opened to stop the motor. This is accomplished
electromechanically using start and stop pushbuttons or other
pilot devices wired to control the contactor.
of Control Components you learned how various control
products are used to control the operation of motors. The most
basic type of AC motor control, for example, involves turning
the motor on and off. This is often accomplished using a motor
starter made up of a contactor and an overload relay.
The contactor’s contacts are closed to start the motor
and opened to stop the motor. This is accomplished
electromechanically using start and stop pushbuttons or other
pilot devices wired to control the contactor.
The overload relay protects the motor by disconnecting power
to the motor when an overload condition exists. Although the
overload relay provides protection from overloads, it does not
provide short-circuit protection for the wiring supplying power
to the motor. For this reason, a circuit breaker or fuses are also
used.
to the motor when an overload condition exists. Although the
overload relay provides protection from overloads, it does not
provide short-circuit protection for the wiring supplying power
to the motor. For this reason, a circuit breaker or fuses are also
used.
Typically one motor starter controls one motor. When only a
few geographically dispersed AC motors are used, the circuit
protection and control components may be located in a panel
near the motor.
few geographically dispersed AC motors are used, the circuit
protection and control components may be located in a panel
near the motor.
motor control center (MCC).
In many commercial and industrial applications, quite a few
electric motors are required, and it is often desirable to control
some or all of the motors from a central location. The apparatus
designed for this function is the motor control center (MCC).
Motor control centers are simply physical groupings of
combination starters in one assembly. A combination starter is
a single enclosure containing the motor starter, fuses or circuit
breaker, and a device for disconnecting power. Other devices
associated with the motor, such as pushbuttons and indicator
lights, may also be included.
electric motors are required, and it is often desirable to control
some or all of the motors from a central location. The apparatus
designed for this function is the motor control center (MCC).
Motor control centers are simply physical groupings of
combination starters in one assembly. A combination starter is
a single enclosure containing the motor starter, fuses or circuit
breaker, and a device for disconnecting power. Other devices
associated with the motor, such as pushbuttons and indicator
lights, may also be included.
tiastar
tiastar (pronounced tie-star) is the trade name for Siemens
Motor Control Centers
Motor Control Centers
Some of the advantages of using tiastar motor control centers are:
• Ruggedness and reliability
• Reduced time needed for installation and startup
• Space saving design
• Excellent component selection
• Simplicity in adding special components
• Ease of future modifications.
• Reduced time needed for installation and startup
• Space saving design
• Excellent component selection
• Simplicity in adding special components
• Ease of future modifications.
The TIA
The TIA portion of the tiastar name stands for Totally
Integrated Automation. TIA is more than a concept. It is a
strategy developed by Siemens that emphasizes the seamless
integration of automation, networking, drive, and control
products. The TIA strategy has been the cornerstone of
development for a wide variety of Siemens products.
TIA is important not just because it simplifies the engineering,
startup, and maintenance of systems developed using Siemens
products, but also because it lowers the life-cycle costs for
systems incorporating these products. Additionally, by reducing
engineering and startup of systems, TIA helps Siemens
customers reduce time to market and improve overall financial
performance.
Integrated Automation. TIA is more than a concept. It is a
strategy developed by Siemens that emphasizes the seamless
integration of automation, networking, drive, and control
products. The TIA strategy has been the cornerstone of
development for a wide variety of Siemens products.
TIA is important not just because it simplifies the engineering,
startup, and maintenance of systems developed using Siemens
products, but also because it lowers the life-cycle costs for
systems incorporating these products. Additionally, by reducing
engineering and startup of systems, TIA helps Siemens
customers reduce time to market and improve overall financial
performance.
