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motor control panel

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Basics of Motor Control Centers :

Basics of Motor Control Centers Presented By Engr.UMAIR ALTAF Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Power Distribution Systems: Distribution systems used in large commercial and industrial facilities can be complex. In these facilities, power may be distributed through switchgear, switchboards, motor control centers, transformers, and panel boards. This power is used for a variety of applications such as heating, cooling, lighting, office equipment, appliances, and motor-driven machinery. Motor Control Centers: 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. Many types of components used in motor control centers are uniquely designed for motor control. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Basic Motor Control: While manual operation of machines is still common, many machines are controlled automatically. Frequently there is a combination of manual and automatic control. For example, a process may be started manually, but stop automatically when certain conditions are met . Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Enclosed Motor Starters: 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 an enclosure near the motor. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Motor Control Center Definition: According to NEMA standards publication ICS-18-2001 a motor control center is a floor-mounted assembly with the following characteristics. One or more enclosed vertical sections Horizontal and vertical buses for distributing power Principally contains combination motor control units Vertical Sections The motor control center is made up of a steel structure to contain the combination motor control units, wireways , internal wiring, and bus bars. From the NEMA definition it can be seen that a motor control center is a floor-mounted assembly made up of enclosed vertical sections. One vertical section may stand alone as a complete motor control center, or several sections may be bolted and bussed together Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Vertical sections are generally 20" wide by 90" high, but structures less than 90" are available, and structures wider than 20" are sometimes used. Additional dimension information is provided later in this course. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Enclosure Types An enclosure surrounds equipment to protect personnel from contact with live buses or connections and to protect equipment from external conditions. The amount of environmental protection an enclosure provides depends on the type of enclosure. The following enclosures types are available for motor control centers . Type 1 - Standard - Indoor Type 1A - Gasket Front - Indoor Type 2 - Drip-Proof - Indoor Type 12 - Dust Tight - Indoor Type 3R - Rainproof – Outdoor Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers MCC Voltage Rating In addition to the various ratings of individual components used in motor control centers, motor control centers also have an overall rating of 600 volts. This is the maximum voltage that can be applied to a motor control center. A motor control center can be connected to a lower voltage, however, and a three-phase, 480 VAC supply voltage is common. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Main Lugs: There are several ways incoming power can be terminated in a motor control center. Cable can be routed directly to the incoming power lugs, to main breakers or disconnects, or to a terminal block in a vertical section. Also, incoming power cables can enter and exit the motor control center from the top or bottom depending on the application. Finally, incoming power can be provided using busway . Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Power Cable Entry: incoming power cables can enter through the top or bottom of a vertical section. If the power cables enter through the top of the enclosure, they connect to main lugs at the top of the vertical bus. If the power cables enter the enclosure through the bottom, two connection arrangements are available. Main lugs can be located at the bottom of the vertical bus, or the power cables can be routed to main lugs at the top of the vertical bus. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Main Disconnect Device: When a main disconnect device is used, the disconnect is mounted in its own unit. The amount of space required depends on the disconnect used. The space can vary from 12" to 72". Cable entry can be from the top or bottom of the vertical section When a circuit breaker is used as a main disconnect device, this device can be configured to utilize its Dynamic Arc Flash Sentry (DAS) feature which allows alternative breaker settings with a lowered potential arc flash energy to be employed when personnel are working near energized equipment . Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Vertical and Horizontal Buses: A bus is a conductor that serves as a common connection for two or more circuits. It is represented schematically by a straight line with a number of connections made to it. In power circuits, such as motor control centers, a bus is made of heavy-duty metal bars. These bus bars provide power to each of the combination motor control units. A vertical bus bar is connected to a corresponding horizontal bus bar and is isolated from the other bus bars. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Disconnect Operating Handle The disconnect operating handle has four positions: ON, TRIP, OFF, and PARK. The TRIP position applies only to circuit breaker equipped units. The unit disconnect operating handle design shows ON, OFF, and TRIP indication by color, position, and label. To open the unit door, the disconnect operating handle is moved past the OFF position to the PARK position The disconnect operating handle is mechanically interlocked to prevent the door from opening with the disconnect ON or the disconnect from closing with the door open. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Motor Starters: The motor starter is the heart of the combination motor control unit. The most common type of starter is the full-voltage starter which consists of a contactor and an overload relay. The contactor portion of a motor starter provides the means to remotely start and stop a motor. The overload relay protects the motor from overload conditions. While full-voltage starters are the most common type of starter, other types of starters are also available . The following types of starters are available for use in motor control centers: FVNR - Full-Voltage, Non-Reversing FVR - Full-Voltage, Reversing 2S1W - Two-Speed, One Winding, Reconnect able Consequent Pole Unit 2S2W - Two-Speed, Two Winding PW - Full-Voltage, Part Winding RVAT - Reduced-Voltage Auto-Transformer (Closed Transition) YD - Wye Delta (Open or Closed Transition) RVSS - Reduced-Voltage Solid State (Soft Starter) VFD - Variable Frequency Drive Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Variable Frequency Drives: An AC drive is an electronic device that, in addition to controlling speed, may control other quantities, but that depends upon the capabilities of the drive and the needs of the application. Because the type of motor being controlled is often an AC induction motor and the speed of this motor is dependent upon the frequency of the AC power applied, an AC drive is often referred to as a variable frequency drive, or VFD for short. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Pilot Devices: A variety of pilot devices can be used in motor control centers. Pilot devices include pushbuttons, selector switches, and pilot lights. A pushbutton is a control device used to manually open and close a set of contacts .. Selector switches are also used to manually open and close contacts . Selector switches are available in 2-position, 3-position, and 4-position types. Pilot lights provide visual information of the circuit's operating condition. Pilot lights are normally used for ON/OFF indication, caution, changing conditions, and alarm signaling. Pilot lights come with a color lens, such as red, green, amber, blue, white, or clear. Engr. Umair Altaf

Basics of Motor Control Centers :

Basics of Motor Control Centers Power Meters: I n addition to devices used to directly control or protect motors and related equipment, motor control centers can incorporate a variety of other devices such as power meters, programmable logic controllers (PLCs), power distribution equipment, etc. Power meters can be included in motor control centers to measure real-time RMS values of phase currents, phase and line voltages, power usage, power factor, KW, frequency, and peak demand. Engr. Umair Altaf

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