Table of Contents Introduction............................................................................ 2 Siemens Industry, Inc.............................................................. 4 Electric Power......................................................................... 5 Residential Applications........................................................ 10 Commercial Applications....................................................... 20 Industrial Applications.....................................
Introduction Welcome to another course in the STEP series, Siemens Technical Education Program, designed to help our distributors and customers better understand Siemens Industry, Inc. products. This course covers Basics of Electrical Products.
Siemens is a trademark of Siemens AG. Product names mentioned may be trademarks or registered trademarks of their respective companies. Specifications subject to change without notice. National Electrical Code® and NEC® are registered trademarks of the National Fire Protection Association, Quincy, MA 021697471. NEMA® is a registered trademark and service mark of the National Electrical Manufacturers Association, Rosslyn, VA 22209. Underwriters Laboratories Inc.
Siemens Industry, Inc. Company Overview The objective of this course is to provide a high-level overview of those products of Siemens Industry, Inc. (SII) which are sold by our channel partners and fall into the following categories: low voltage power distribution, motors, control, drives, and industrial automation. It is beyond the scope of this course to cover all SII products. For more information on SII products, refer to the Siemens Industry, Inc. web site. Before discussing Siemens Industry, Inc.
Electric Power Power, originating at a power generating plant, is distributed to residential, commercial, and industrial customers through various transmission lines and substations. Power Sources There are several energy sources used to produce electrical power. For example, coal, oil, and uranium are fuels used to convert water into steam which, in turn, drives a turbine. Some utilities also use gas turbines, or, for combined cycle operation, both gas and steam turbines.
Hydroelectric Power Hydroelectric power plants use mechanical energy from falling water to turn a generator. Newer Renewable Energy Sources Of the power generation approaches discussed so far, only hydroelectric power is a renewable energy source. Hydroelectric power has been around from the earliest days of electric power generation. In recent years, a small, but growing, percentage of electrical energy is generated using wind or solar power or through a host of other renewable approaches.
If you track the rotation of the AC generator through a complete revolution of 360°, you would see that, during the first quarter of a revolution, voltage increases until it reaches a maximum positive value at 90°. Voltage decreases during the second quarter of a revolution until it reaches zero at 180°. During the third quarter of a revolution, voltage increases in the opposite direction until it reaches a maximum negative value at 270°.
Transformers Once the electrical energy gets near the end user, the utility steps down the voltage to the level needed by the user. The device that utilities use to step up the voltage at the generator end and step down the voltage at the user end is called a transformer. The transformer transfers energy from a primary coil to a secondary coil by mutual induction. The AC generator provides electrical power to the primary coil.
Three-Phase Transformers Transformers used with three-phase power require three interconnected coils in both the primary and the secondary. These transformers can be connected in either a wye or a delta configuration. The type of transformer and the actual voltage depend on the requirements of the power company and the needs of the customer. The following illustration shows the secondary of a wyeconnected transformer and the secondary of a delta-connected transformer.
Residential Applications Power, generated at a power plant and stepped up to a high transmission voltage, is brought to a local substation. Here, it is stepped down to a lower distribution voltage. When it reaches its final destination at a residential customer, it is stepped down to 240 volts. Only single-phase power is used in a typical residential application. Power Supply The most common supply system used in U.S. residential applications today is a single-phase, three-wire supply system.
Siemens Generators Although the power from electric companies is usually reliable enough for residential applications, many homeowners and businesses desire standby or portable generators. Siemens generators are designed for quiet and reliable operation. Siemens offers generators in a range of capacities along with associated equipment, such as transfer switches and manual transfer interlock kits. Microinverters Solar panels are another source of power for homes and commercial facilities.
Meter Mains and Meter Load Center Combinations Meter mains and meter load center combinations are similar. Meter mains incorporate space for a watt-hour meter and a main service disconnect within the same enclosure. Meter load center combinations incorporate space for a watt-hour meter and circuit breakers in the same enclosure. Because application requirements vary significantly, Siemens offers various types of meter mains and meter load center combinations.
Residential Power Distribution After passing through a meter, incoming power usually goes to a load center. Load center is an industry term used to identify a type of panelboard used in residential or light commercial applications. As previously indicated, this load center may be combined in the same enclosure with a meter socket. Often, however, a separate load center is provided.
Circuit Breakers Circuit breakers provide a manual means of energizing and deenergizing a circuit and overcurrent protection for the connected circuits. Residential circuit breakers are typically 1-pole, 2-pole, or 4-pole breakers with current ratings of 225 amps or less and voltage ratings of 120 volts, 120/240 volts, or 240 volts.
AFCI Circuit Breaker Arc faults are electrical arcs which result when current flows in unintended ways, but, in residential applications, often not in sufficient amounts to cause a standard circuit breaker to trip. Arc faults in residential applications typically result from worn or damaged insulation and are a common cause of fires.
Siemens residential products include devices intended to minimize damage from electrical surges. For example, Siemens Circuit Breaker and SPD replaces two full-size, 1-pole circuit breakers and provides surge protection for all branch circuits. Circuit Breaker and SPD 20 Protected when lit QSA2020 20 Type QP Circuit Breaker and SPD Siemens also offers the following surge protection devices (SPDs) for use in residential and light commercial applications.
Special Application Panels Siemens Generator Ready Load Center is a UL listed 200 A, 30 circuit, 42 space indoor load center that provides an effective solution for implementing generator backup of critical circuits. Both main lug only and main breaker versions are available.
Enclosed Circuit Breakers and Disconnects Siemens manufactures circuit breaker enclosures and fused, non-fused, and molded case switch disconnects. Enclosed circuit breakers and disconnects provide a convenient means of disconnecting power to allow for the maintenance of equipment, such as an air conditioner.
Review 1 1. ________ incorporate space for a watt-hour meter and a main service disconnect in the same enclosure. 2. _________ and _________ provide enclosure options for the multiple watt-hour meters required in multiple family dwellings. 3. Siemens PL and ES load centers have continuous current ratings from ___ to ___ amps. 4. Siemens ________ AFCI circuit breakers provide protection against all three known types of arc faults. 5.
Commercial Applications Commercial applications range from small offices and stores to larger complexes such as hotels, office buildings, and shopping malls. These applications differ in the amount of electrical energy required. Small, single-tenant office buildings, for example, have very limited power requirements. In such cases, a single-position meter socket and panelboard may be sufficient for distributing power.
Busway is a system of enclosed and insulated conductors and associated fittings and accessories manufactured for rapid assembly at the job site. Siemens offers a variety of busway systems including Sentron busway. Sentron busway has an easy to install design and is available with continuous current ratings from 225 to 5000 amps. Service Entrance Outdoor feeder busway is often used as service entrance conductors to bring power to a switchboard or panelboard.
The Busway Advantage A major advantage of busway is the ease in which busway sections are connected together. Electrical power can be supplied to any area of a building by connecting standard lengths of busway. It typically takes less labor to install or change a busway system than cable and conduit assemblies. Savings of 25 to 30% of the total installation cost are common when busway is used.
Panelboard Construction The load centers discussed previously in this course are panelboards designed for residential or light commercial applications. Panelboards used in most commercial applications, however, are generally more rugged in construction and able to handle larger amounts of current. Access Door Trim Dead Front Interior Enclosure (Can) Panelboards Siemens manufactures a range of panelboard models to meet various distribution requirements.
The P3 panel is also a flexible and innovative panel. P3 panels are sized more like a lighting and appliance panel for those tight areas, but able to handle many power distribution panel applications. P3 panels are available with continuous current ratings up to 800 amps for main lug only panels and 600 amps for main breaker panels. The P4 panel is a mid-sized power distribution panel that can include fusible switches as well as circuit breaker main and branch devices.
Switchboard Construction Switchboards typically consist of a service section with a main circuit breaker or main fusible switch and one or more distribution sections. The service section can be fed directly from the utility transformer. In addition to the main disconnect, the service section usually contains utility or customer metering provisions.
Integrated Power System (IPS) Switchboard The modular design of Siemens Integrated Power System (IPS) switchboard allows the customer to integrate electrical distribution equipment, power monitoring, and environmental controls that typically mount in multiple enclosures into one switchboard line-up. Customers have the freedom to configure an arrangement that best fits their needs. Optional factory installed interconnection wiring is available to further reduce installation time.
Super Blue Pennant Switchboard Siemens Super Blue Pennant switchboard is a service entrance switchboard with main service disconnect and distribution devices contained in a single unit that meets Electric Utility Service Equipment Requirements Committee (EUSERC) specifications. These switchboards are rated for 400, 600, or 800 amps with a circuit breaker main and 400 or 600 amps with a fusible Vacu-Break switch main.
Panelboard Example When deciding between a panelboard and a switchboard in commercial applications, it is not always clear which product you should chose. In the following small commercial application example, up to 1200 amps at 480 volts is supplied by the utility to a power panelboard. Multiple circuits are used to supply power throughout the facility. For simplicity, only a few devices are shown.
From the limited information provided in the two previous examples, except for the maximum service current requirement, it is not obvious whether a power panelboard or a switchboard should be used at the service entrance. This determination is usually made by the customer or a consulting engineer based on the overall requirements of the application. The service entrance and other application requirements are then detailed in specifications communicated to potential suppliers in a request for proposal (RFP).
While some thermal-magnetic circuit breakers have an adjustable trip curve, the adjustment is limited. Circuit breakers with a solid state trip unit, on the other hand, typically have multiple adjustments. In the past, choosing the variety of circuit breaker types needed for many applications required selection of circuit breakers with varied designs, locking users into extensive spare parts requirements. In response to this problem, Siemens developed the VL global family of molded case circuit breakers.
Another category of large circuit breakers is the low voltage (LV) power circuit breaker. LV power circuit breakers are generally drawout mounted and may be used in switchboards or switchgear. LV power circuit breakers intended for use in the United States conform to IEEE standards (C37.13, C37.16, C37.17, and C37.50). The corresponding UL specification for LV power circuit breakers is UL 1066.
HCP Fusible Switches Siemens high contact pressure (HCP) fusible switch is another device that can be used as a disconnect device in panelboards and switchboards. Visible contacts provide a visual indication concerning the state of the switch before servicing. HCP fusible switches are available with ampere ratings from 400 to 1200 amps. HCP fusible switches are suitable for use on systems with up to 200,000 amps of available fault current when used with class J or class L fuses.
Transient Protection System (TPS3) Many types of equipment, especially computers and office equipment, are susceptible to the high energy levels associated with electrical surges, which can be caused by lightning or electrical equipment operation. Any component between the source of the surge and ground can be damaged. In response to this problem, Siemens Transient Protection System (TPS3) offers UL 1449 3rd edition surge protection devices (SPDs) to fit every level of the electrical distribution system.
VBII Safety Switches A safety switch is a type of enclosed switch. Fusible safety switches include provisions for fuses, non-fusible safety switches do not. Siemens VBII safety switches are available in general duty, heavy duty, and double throw designs. A common use for a single throw safety switch is to provide a disconnecting means and fault protection for a motor circuit.
Motor Starters Although safety switches can be used to start and stop motors, many motor applications require the use of remote control devices to start and stop the motor. Motor starters are commonly used to provide this function. In addition, some motor starters have multi-speed and reversing capability. When the motor starter is contained in the same enclosure with a fusible disconnect switch or circuit breaker, it is referred to as a combination starter.
Review 2 1. Siemens P1 panelboards are available with current ratings up to ______ amps. 2. Siemens P5 panelboards are available with continuous current ratings up to _______ amps for main breaker, main switch, and main lug only panels. 3. Siemens SB1 switchboards have through bus ratings up to _____ amps at 600 VAC. 4.
Industrial Applications Voltage Classes The power distribution equipment discussed thus far is often referred to as low voltage equipment, but there are different definitions for low voltage and other voltage classes. For the purposes of this discussion of power distribution equipment, low voltage (LV) systems operate at 1000 volts (1 kV) or less and medium voltage (MV) systems generally operate between 1000 and 38,000 volts (1 to 38 kV).
Switchgear The term switchgear is used to describe a compartmentalized system of coordinated devices used for power distribution control and circuit protection. Essentially, switchgear performs the same function as the switchboards previously described, but different standards dictate the design of switchgear. In addition, because MV switchgear must handle higher levels of electrical energy and be capable of interrupting higher fault currents, it is larger and more heavily constructed.
WL Low Voltage MetalEnclosed Switchgear WL low voltage metal-enclosed switchgear is manufactured by SII and incorporates WL low voltage power circuit breakers. WL low voltage switchgear is similar to Siemens switchboard products, which can also employ WL circuit breakers. However, WL low voltage switchgear conforms to IEEE and UL standards that differ from NEMA and UL switchboard standards. A WL switchgear assembly consists of one or more metal enclosed vertical sections.
Secondary Unit Substations Some customers require an integrated assembly, called a secondary unit substation, to provide electrical service to a facility. A secondary unit substation consists of a primary switch and one or more transformers mechanically and electrically connected to switchboard or switchgear sections. All elements of the substation are engineered to the specific needs of the application. The incoming service to the primary switch is typically rated for 2.4 to 13.8 kV.
Large Industrial Facility Power Distribution Example Even in large industrial facilities, supply voltage must be reduced to a level that can be used by most electrical equipment. While some machines require voltages above 480 volts, most factories use AC motors, drives, motor control centers, and other devices that operate on 3-phase, 480 volts and other equipment that requires even lower 1-phase or 3phase voltages.
Busway Busway is widely used in industrial applications to distribute power. There are different types of busway, however. Feeder busway is used to conduct feeder current to loads that are sometimes remote from the power source. Plug-in busway, on the other hand, incorporates plug-in units, called bus plugs, to allow loads to be distributed over the length of the run. Many industrial applications require both types of busway.
Siemens Busway Siemens manufactures a variety of busway types to meet varied application requirements. SENTRON Busway is a flexible power distribution solution with an easy-to-install single bolt joint stack design, optional 200% neutral or isolated ground, and ratings from 225 to 5000 amps.
Manufacturing Applications Thus far, this course has primarily centered on Siemens products used to distribute power throughout residential, commercial, and industrial applications. In all these applications, this electrical energy is also used for lighting, heating, air conditioning, office equipment, and other non-industrial systems. Unlike commercial and residential applications, however, in industrial applications most of the electrical energy is used to power manufacturing equipment.
In general, we can say that most manufacturing processes incorporate one or more of the following process types: Discrete Parts Manufacturing Assembly Batch Processing Continuous Processing The process type included in the overall manufacturing process depends upon the products being produced. Some industries, for example, are dominated by a specific process type.
Discrete Parts Manufacturing Manufacturing discrete parts typically requires the use of multiple machines. Machines are used to move and store raw materials, transform raw materials into finished parts, package and store parts, prepare parts for shipment, and a host of related activities. Totally Integrated Automation (TIA) Although the various machines used in this process differ, a typical machine needs some type of control system.
Input Devices The PLC receives signals from various switches and sensors in the controlled machine or related equipment. Many of these signals are on/off type conditions, also called discrete or digital signals. In some cases, the signals come from manual devices such as pushbuttons and selector switches. However, many discrete PLC inputs come from devices, such as limit switches or proximity switches, that are turned on and off by machine operations.
SIRIUS Modular System Siemens manufactures an extensive array of components and systems that can be utilized for machine control applications. One such system is the SIRIUS modular system of industrial controls which incorporates components in each of the following categories: switching, protecting, starting, monitoring and controlling, detecting, commanding and signaling, and supplying. Where varied power requirements are needed, the SIRIUS modular system provides a range of options.
Human Machine Interface A Human Machine Interface (HMI) is any device that acts as a link between the operator and the machine. Typically, however, the term HMI refers to devices that display machine or process information and provide a means for entering control information. Siemens SIMATIC HMI products provide a range of options from the operator control and monitoring devices and visualization software needed for machine-level interfaces to scalable systems for plant-wide process control.
As the S7-1200 PLC executes its control program, it receives inputs from manual switches mounted on the front of the panel. It also communicates with a SIMATIC HMI operator panel that provides for manual inputs from the machine operator or maintenance person and displays alphanumeric messages indicating machine status. The PLC also receives inputs from other control devices such as limit switches or proximity switches that change state as a result of machine operations.
Servo Drive Operator Panel Machine Control Panel SIMATIC S7 PLC Servo Motors Review 4 1. An example of a device that might be controlled by a PLC discrete output is a ____________. a. limit switch b. relay c. proximity switch d. selector switch 2. The ________ modular system of industrial controls incorporates components in each of the following categories: switching, protecting, starting, monitoring and controlling, detecting, commanding and signaling, and supplying. 3.
Assembly Processes Assembly processes may involve assembling an entire system or subsystem at one location. In many cases, however, parts are mounted sequentially through a series of assembly stations. Units being assembled are moved from station to station via some type of transporter mechanism, such as a conveyor. Any specific assembly station may utilize only manual assembly operations or may include one or more machine operations.
NEMA Motor Motor Control IEC Motor Wherever motors are used, they must be controlled. The most basic type of AC motor control involves turning the motor on and off. This is often accomplished by using a motor starter made up of a contactor and an overload relay. In the example shown in the following illustration, the contactor closes its main contacts and starts the motor when the Start pushbutton is pressed. When the Stop pushbutton is pressed, the contactor opens its contacts and stops the motor.
An MCC is a sectionalized structure with control components for each motor mounted in a removable container called a pan or bucket. In addition to combination motor control units, motor control centers can also include items such as reduced-voltage starters, variable speed drives, and PLCs. Siemens tiastar MCCs have been designed to incorporate a variety of Siemens products that offer optimal motor control, communications, monitoring, protection, and automation interfacing.
SIMOCODE PRO V DEVICE BUS GEN. FAULT SIMOCODE PRO PROFIBUS DP READY TEST/ RESET DM 24V MO READY DEVICE TM lmax 22.68A UL1 329V Cos Phi 72% P 15.700 kW 30.25A/10T Menu BUS GEN. FAULT 0 SIMOCODE pro V SIRIUS 3R Reduced Voltage Starters While it is common to turn motors on and off instantaneously, this abrupt transition results in power surges and mechanical shock that may need to be avoided, especially when larger motors are involved.
Low Voltage AC Drives Each of these classes is further divided. For example, Siemens low voltage AC drives include general purpose drives, general purpose enclosed drives, high-performance drives, and highperformance enclosed drives. The complete list of Siemens low voltage AC drives is far too extensive to describe in this course, but the following paragraphs provide summary information. At the low end of the power range is the SINAMICS G110, the smallest member of the SINAMICS family.
DC Drives Although AC motors are more commonly used, many factories also use DC motors for selected applications. In many of these applications, precise control of motor speed and torque is required. For these applications Siemens offers the SINAMICS DC MASTER family. Motion Control Earlier in this course, you learned that Siemens provides a range of products for use in machine tool control applications. Machine tool applications are not the only applications that require precise motion control.
Identification Systems Assembly applications frequently require identification of objects used or manufactured. This is accomplished by systems that read codes, optical characters, or radio frequency identification (RFID) tags associated with these objects. Siemens hand-held and stationary code readers provide reliable, flexible reading, verification and optical character recognition (OCR). Siemens RFID systems utilize a different technology for sensing objects.
A variety of programming options are available. This includes basic programming languages (Instruction List, Ladder Diagram, and Function Block Diagram) as well as more as well as alternative approaches such as S7-SCL (Structured Control Language), S7-Graph, S7-HiGraph, and S7-CFC (Continuous Function Chart). Modular SIMATIC controllers are optimized for control tasks and can be adapted to meet application requirements using modules for input/output (I/O), special functions, and communications.
TIA Portal Totally Integrated Automation Portal (TIA Portal) is an innovative engineering framework that unifies multiple automation tools into a single, intuitive development environment, enabling controller programming, HMI screen design, and other automation tasks to be performed using a similar editor design.
Industrial Networks In any complex assembly process, the need for rapid information flow is critical. Conditions at any point in the process may impact the entire process. This need for information flow often requires that intelligent devices such as PLCs, intelligent sensors, drives, computers, and HMI systems be interconnected by one or more local area networks (LANs). A LAN is a communication system designed for private use in a limited area.
The Siemens SIMATIC NET product family includes a range of SCALANCE X Industrial Ethernet switches to fit varied requirements from localized to plant-wide networks. Siemens also offers an extensive array of devices for interconnecting network components via twisted-pair cable, optical fiber, or wireless signals. For example, Siemens FastConnect system includes cables and connectors designed for demanding factory applications and a cable stripper designed to speed installation.
IO-Link is an open communication standard developed by the IO-Link research group of the PROFIBUS & PROFINET International organization in response to the need for a simple, low-cost way to allow actuator and sensor communication in a concentrated area, such as for a control panel or individual machine. IO-Link is a point-to-point system, not a fieldbus. It uses a three-wire cable, 24 VDC power supply, and an IO-Link master.
SIMATIC IT Manufacturing Execution System There are a variety of manufacturing information technology (IT) systems. For example, manufacturing facilities have long used Enterprise Resource Planning (ERP) systems to manage the flow of materials associated with manufacturing processes. In recent years, many companies have also been using a Manufacturing Execution System (MES).
Batch and Continuous Processes Thus far, we have discussed equipment used in discrete parts manufacturing or assembly applications. In addition to these types of manufacturing processes, electrical equipment is also used to manufacture a variety of products using batch or continuous processes. Batch Processes Batch processes are familiar to most people since we use them in everyday life.
Continuous Processes Continuous processes are less understood by most people; however, they have some similarities to batch processes. Ingredients must be combined in precise ways at precise points in the process. Precise control of process conditions must be maintained to ensure product quality and safety of operations. Some industries, such as chemical and petrochemical industries, use continuous processes extensively.
Process Instrumentation Because process types and requirements vary widely, many types of sensors, transmitters, actuators, and other devices are used for process measurement and control. The following product families are examples of the types of process instrumentation products Siemens offers. • • • • • • • SITRANS P products provide a range of instruments for measuring relative, differential, and absolute pressure.
Process Visualization The range of SIMATIC HMI operating and monitoring products includes three software families: SIMATIC WinCC (TIA Portal), SIMATIC WinCC, and SIMATIC WinCC Open Architecture We have already discussed one of these families, SIMATIC WinCC (TIA Portal). SIMATIC WinCC is a scalable, Windows-based process visualization system, or what is sometimes called a supervisory control and data acquisition (SCADA) system.
Traditionally, medium to large process applications have been controlled by a distributed control system (DCS) that is based on proprietary hardware and software that often do not integrate well with other systems. By comparison, Siemens SIMATIC PCS 7 uses a more flexible approach. SIMATIC PCS7 uses standard hardware and software from the SIMATIC TIA family.
Review 6 1. _______ control involves measuring a value, comparing the measured value to a desired value, and correcting for the error. 2. _______ products provide a range of instruments for measuring relative, differential, and absolute pressure. 3. _______ is a scalable, Windows-based process visualization system. 4. _______ is a process control system that uses standard hardware and software from the SIMATIC TIA family.
Pictorial Glossary The pictorial glossary includes definitions and illustrations for many terms that are frequently used in the electrical industry. Terms that are underlined and italicized are included in the glossary as a separate definition. AC Drive An electronic device used to control the speed of an AC motor. Also called a variable frequency drive or an inverter. The term variable speed drive applies to both AC Drives and DC Drives.
Ambient Temperature The temperature of the medium (such a air) surrounding a device. American National Standards Institute (ANSI) A nongovernmental organization that promotes and coordinates the development of standards and accredits the procedures of other organizations that develop standards. American Wire Gauge (AWG) A common method of specifying wire size (cross-sectional area). Larger numbers represent smaller wires. After AWG No. 1, the largest sizes are AWG No. 0, AWG No. 00, AWG No.
Analog Output An output from a system that can continuously vary over a range of current or voltage such as 4 to 20 milliamps or 0 to 10 volts. Common Analog Values 0 to 10 VDC 4 to 20 mA Controller Analog Output Arc Chute Assembly Transducer Transmitter The vector sum of true power and reactive power. Apparent power is calculated by multiplying current times voltage. The unit for apparent power is the volt-ampere, abbreviated “VA.
Arc Fault Circuit Interrupter (AFCI) A circuit breaker designed to provide protection from the effects of an arc fault by recognizing the characteristics unique to arcing and de-energizing the circuit when an arc fault is detected. The most effective AFCI circuit breakers are combination AFCIs which provide protection against all three known types of arc faults.
Binary Number A number made up only of 1’s and 0’s that represent powers of two (2). Digital equipment uses binary numbers to represent numerical values and the on or off condition of devices. Most Significant Bit (MSB) Power of 2 2 7 2 6 Least Significant Bit (LSB) 2 5 2 4 2 3 2 2 2 1 2 0 Decimal 128 64 32 16 8 4 2 1 Binary 1 0 0 1 0 0 1 0 10010010 in Binary = 146 in Decimal Bit A 1 or 0 representing one position in a binary number.
Bus Bar A conductor that serves as a common connection for two or more circuits. Bus Bars Bus Plug A device used with plug-in busway to provide power connections close to the intended load. Bus Plug Busway A prefabricated electrical distribution system that uses bus bars in a protective enclosure. Busway Busway Hangers Devices used to suspend busway from a ceiling or mount it to a wall. Floor Support Hangers Wall Support Hangers Picture Frame Hanger Byte Eight consecutive bits.
Capacitance The property of a circuit or device that allows it to store an electrical charge. The symbol for capacitance is “C.” The unit for capacitance is the farad. Capacitive Proximity Switch A type of sensing switch that produces an electrostatic field to detect the presence of an object without touching the object. Sensor Face Target (Metalic or Non-metalic) Capacitive Reactance The opposition to alternating current resulting from circuit capacitance.
Circuit Breaker A device that can be used to open or close a circuit manually and also opens a circuit automatically when it senses an overcurrent. Type/Tipo NEG Frame-EG 100 Amp O N O F F Closed-Loop Control l O 100 A control technique that compares a feedback signal representative of an actual value with a desired value and responds to minimize the error.
Control Relay Often refers to a device with contacts that open and close electromagnetically, but solid state control relays are also available. Control relays typically handle smaller currents than contactors, but are capable of switching more rapidly.
DC Drive An electronic device used to control the speed of a DC motor. The term variable speed drive applies to both DC Drives and AC Drives. SINAMICS DC Master Drives DC Motor A motor that converts direct current electrical energy into mechanical energy. Dead Front A front portion of a panelboard or switchboard that limits exposure to electrical connections. Dead Front Delta A connection arrangement used for the primary and/or secondary of a three-phase transformer.
DIN Rail A mounting bracket manufactured to German Institute for Standardization (DIN) specifications. Typically used to mount devices such as small PLCs, motor starters, control relays, power supplies, and other components that are DIN rail compatible. DIN Rail Diode A component with two terminals (anode and cathode) that passes current primarily in one direction. Often used as part of a rectifier circuit.
Distribution Section A switchgear, switchboard , or power panelboard section that receives power from the service section and distributes power to other circuits. Distribution Section Service Section Duty Cycle The ratio of a device’s on time to its total cycle time. Duty cycle is normally expressed as a percentage; therefore, a device with a 50% duty cycle is on half the time.
Encoder Often refers to a digital device that provides angular position information. Some encoders provide this information as incremental pulses as position changes. Other types of encoders provide a digital signal representative of absolute position. Erasable Programmable Read Only Memory (EPROM) A type of semiconductor memory often used for storage of data or programs that change infrequently, if at all. EPROMs must be removed from the circuit to be erased and reprogrammed.
Four-Quadrant Operation Describes the operation of a variable speed drive that is capable of providing forward or reverse torque with the motor rotating in either the forward or reverse direction. +N Second Quadrant First Quadrant CW Rotation CW Rotation N T -T T N Driving Driving Braking N CCW Rotation Third Quadrant + = Forward - = Reverse T Braking N T = Torque N = Speed +T T CCW Rotation Fourth Quadrant -N Frequency The rate of variation of a periodic waveform.
Ground A connection to the earth or to a conductive object such as an equipment chassis. Transformer Secondary Service Entrance Load Center Neutral Neutral Bonded to Enclosure Grounding Electrode Conductor Grounding Electrode Ground Fault A condition in which current takes an unintentional path to ground. Ground faults can endanger people and damage equipment. For this reason, some circuits are equipped with a ground fault circuit interrupter (GFCI).
Harmonic Distortion The effect of harmonics on the fundamental frequency. Harmonic distortion can interfere with the operation of electronic devices. Fundamental Frequency (First Harmonic) Harmonically Distorted Waveform Third Harmonic Henry The basic unit of inductance. The symbol for the henry is “H.” Hertz A unit of frequency equal to one cycle per second. Hertz is abbreviated Hz. Hexadecimal A number system that uses powers of 16.
Impedance The total opposition to alternating current. Impedance is the vector sum of resistance and reactance. The symbol for impedance is “Z.” The unit for impedance is the ohm. .1 14 XC = 10 Z = XL = 10 4 R = 10 Z = 14 .1 4 R = 10 Inductance The property of an electrical circuit that opposes changes in current. Inductance is designated by the symbol “L” and is measured in henries.
Input/Output (I/O) System The part of a control system that interfaces to the real world. The I/O system accepts signals from switches and sensors, and provides signals to actuating and display devices.
International Organization for Standardization (ISO) A network of standards organizations from over 150 countries that develops voluntary standards for business, science, and technology. The name ISO is from the Greek word “isos,” which means equal. Interrupting Rating The maximum level of fault current that a circuit breaker or fuse can safely interrupt at a specific voltage. The interrupting rating is also called the ampere interrupting rating.
Limit Switch A type of switch that opens or closes its contacts when its actuator is moved by an object. Target Actuator Operating Head Switch Body Load Center An industry term used to identify a lighting and appliance panelboard designed for use in residential and light commercial applications. Local Area Network (LAN) A communication system that interconnects devices within a limited area, but may also connect to other networks for largerscale communication.
Main Breaker The circuit breaker in or upstream from a load center, panelboard, switchboard, switchgear or other equipment that supplies the full current for that equipment. Main Breaker Main Lug Only A designation given to indicate that a main breaker or main switch is not included. Main Lugs MCM Abbreviation for a thousand circular mils. Circular mills are used to designate the cross-sectional area of a round conductor. One mill is equal to 1/1000 of an inch.
Molded Case Circuit Breaker A circuit breaker enclosed in an insulated housing. In the United States, molded case circuit breakers conform to NEMA AB-1 and UL 489 specifications. ! DANGER ! PELIGRO DANGER ! Type/Typo Frame MG ON NMG I Type/Tipo NDG Frame DG OFF 800A O ON I Type/Tipo NDG Frame DG ON OFF I 150A O OFF 150A O Molded Case Switch A switch enclosed in the same type of insulated housing as a molded case circuit breaker.
Motor Insulation Class Standards established by the National Electrical Manufacturers Association (NEMA) to meet motor temperature requirements found in different operating environments. The combination of an ambient temperature of 40°C and allowed temperature rise equals the maximum winding temperature of a motor. A margin is also allowed to provide for a point at the center of the motor’s windings where the temperature is higher.
NEMA Frame Size A designation that identifies motor dimensions based upon standards provided by the National Electrical Manufacturers Association. Motors too large to correspond to NEMA frame sizes are referred to as above NEMA motors. NEMA Motor Design A letter designation based upon standards established by the National Electrical Manufacturers Association that corresponds to a motor’s speed and torque characteristics.
Ohm’s Law A law that states that the current in a circuit is directly proportional to the voltage and inversely proportional to the resistance. E I= R E = Electromotive Force (Voltage) in Volts I = Current in Amperes (Amps) R = Resistance in Ohms Open Drip Proof (ODP) A motor enclosure type that permits air flow through the motor, but is designed to prevent liquids or solids falling from above at angles up to 15 degrees from the vertical from entering the motor.
Overload Relay Class Defines the length of time an overload condition can exist before an overload relay trips. For example, a class 10 overload relay allows 600% of full load amperes for up to 10 seconds. 2 HR 1 HR Trip Time 20 Min 10 Min 4 Min 2 Min 1 Min 30 Sec 20 Sec Class 30 Class 20 10 Sec 4 Sec Class 10 2 Sec 1 Sec 1 2 3 4 56 10 Multiples of Overload Current Pad-Mounted Transformer An enclosed transformer mounted on a concrete pad.
Pilot Light An indicator light typically used to represent a condition in a machine or process. RUN Pilot Light is On STOP Pilot Light is On Motor Running A complete execution cycle of a programmable logic controller. The PLC scan involves updating the status of inputs, executing the user program, performing diagnostic and communication functions, and updating the status of outputs. A PLC scan is repetitively executed.
Power The rate at which work is done or energy is transformed. In an electric circuit, power is measured in watts, or sometimes in horsepower. The term power is also often used to refer to electrical energy and as an adjective to describe devices or circuits designed to carry a high level of current. Power Factor The ratio of true power to apparent power in a circuit. Power factor is also equal to the cosine of the phase angle.
Random Access Memory (RAM) Usually refers to a type of semiconductor memory often used for temporary storage. RAM requires the continual application of power to retain information. For some systems, battery backup is used to prevent data or program loss in the event of a power outage. Reactance The opposition to alternating current resulting from circuit inductance and capacitance. The symbol for reactance is “X.” The unit for reactance is the ohm.
Resistance Temperature Detector (RTD) A device used to sense temperature that varies in resistance as temperature changes. Resistor A device manufactured to have a specific amount of resistance or to be variable within a specific range of resistance. A rheostat is a type of two-lead variable resistor and a potentiometer is a type of three-lead variable resistor. Fixed Value Resistor Rheostat Potentiometer Root-mean-square or RMS Value The effective value of a current or voltage.
Secondary Unit Substation A coordinated design consisting of one or more transformers mechanically and electrically linked to switchgear or switchboard assemblies with an outgoing voltage rated below 1000 volts. Switchboard or Transformer Switchgear Sections Primary Switch Selective Coordination Applying circuit breakers in a manner that minimizes the extent of an outage in the event of a fault. Circuit breakers are typically installed in a branching arrangement.
Sensing Switch A device, sometimes called a sensor, that turns on or off to indicate presence or absence of an object or material. Examples include limit switches and photoelectric , inductive, capacitive, and sonar proximity switches. Service Entrance The place where power cables enter a building. Transformer Load Center Meter Service Entrance Service Factor A numerical value that is multiplied by a motor’s rated horsepower to determine the maximum horsepower at which the motor should be operated.
Servo Drive Usually refers to an electronic device used to control the speed and torque of a servo motor as part of a closed-loop positioning control system. Servo Drive Controller Position Loop Velocity Loop Feedback Servo Motor Servo Motor Machine (1 Axis) Encoder or Resolver A motor designed with the dynamic response required for precision closed-loop positioning applications. Servo Motors Set Point The value used by a control circuit as the desired value of a process variable.
Single Quadrant Operation Describes the operation of a variable speed drive that can provide torque to drive the motor, but cannot provide braking torque. Slip The difference between the synchronous speed of a three-phase induction motor and the rotor speed. Slip is often expressed as a percentage. NS - NR % Slip = NS x 100 NS = Synchronous Speed NR = Rotor Speed Solid-State Used to describe equipment that contains semiconductor devices in an electronic circuit.
Starter Ratings Motor Starters are rated according to size and type of load. NEMA and IEC rate motor starters differently. IEC-rated devices are rated according to maximum operational current. NEMA specifies sizes from size 00 to size 9.
Step-up Transformer A transformer with fewer turns of wire in its primary coil than in its secondary coil. The step-up transformer is used to step up the primary voltage to a higher secondary voltage.
Synchronous Speed The speed of the rotating magnetic field in a three-phase motor. Synchronous speed is determined by the line frequency and the number of motor poles. Synchronous Speed (Ns) = 120f P f = frequency P = number of poles Thermal-Magnetic Used to describe a device that uses both heat and magnetism as part of its operating principles. For example, a thermal-magnetic circuit breaker can be tripped either by heat or magnetic force resulting from an overcurrent.
Torque A turning or twisting force. Since torque is expressed as a force times the length of the radius at which the force is measured, torque is represented in compound units such as pound-feet (lb.-ft.) Force Distance Totally Enclosed Fan Cooled (TEFC) A motor enclosure type that restricts the flow of air into or out of the motor, but uses a fan to blow air over the motor’s exterior.
Trip Unit The part of the circuit breaker that determines when the breaker will trip. Many circuit breakers use a thermal-magnetic or magnetic-only trip unit. Other circuit breakers have a solidstate trip unit with multiple adjustments to custom fit the circuit breaker’s time current curve to the application.
Variable Speed Drive An electronic drive device used to control the speed of an electric motor. This term applies to both AC Drives and DC Drives. Vector Control A technique employed by some variable frequency drives that involves calculations of AC motor current vectors and precise control of motor flux to provide excellent speed and torque control. Volt The basic unit of voltage. The symbol for volt is “V.” Voltage Also called difference of potential, electromotive force, or EMF.
Review Answers Review 1 1) Meter mains; 2) Uni-Pak meter centers, Power Mod with QuickSystem modular metering; 3) 100, 225; 4) combination; 5) SPD. Review 2 1) 400; 2) 1200; 3) 2000; 4) IPS; 5) VL; 6) WL; 7). general, heavy, double throw. Review 3 1) GM-SG; 2) four; 3) secondary unit substation; 4) Feeder, Plug-in; 5) SENTRON. Review 4 1) b; 2) SIRIUS; 3) SITOP; 4) SINUMERIK. Review 5 1) tiastar; 2) SIMOCODE pro; 3) 3RW30, 3RW40, 3RW44; 4) G110; 5) SIMOTION; 6) SIMATIC.
Final Exam Instructions Before taking the final exam, it is recommended that you delete the temporary internet files from your computer’s web browser. For most versions of Internet Explorer, you can do this by selecting Internet Options from the Tools menu and then clicking on the Delete Files button. If you do not perform this step, you may see a score of 0% after you submit your exam for grading. The final exam for this course is available online at http://www.usa.siemens.com/step.
