Document Outline

• LVSAM-WP001A-EN-P April 2009_HQ.pdf
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  • 1 Load characteristics and utilization categories
    • 1.1 Utilization categories simplify the selection of devices
    • 1.2 Electrical heating devices
    • 1.3 Lamps and illumination equipment
      • 1.3.1 Incandescent lamps
        • 1.3.1.1 Halogen lamps
      • 1.3.2 Discharge lamps
    • 1.4 Transformers
    • 1.5 Reactive power compensation and switching of capacitors
      • 1.5.1 Reactive power compensation
        • 1.5.1.1 Individual compensation
        • 1.5.1.2 Group compensation
        • 1.5.1.3 Central compensation
      • 1.5.2 Switching of capacitors
        • 1.5.2.1 Switching-on single capacitors
        • 1.5.2.2 Switching of long, screened lines
        • 1.5.2.3 Switching capacitors of central compensation units
    • 1.6 Control circuits, semiconductor load and electromagnetic load
    • 1.7 Three-phase asynchronous motors
      • 1.7.1 Principle of operation
        • 1.7.1.1 Slip-ring motors
        • 1.7.1.2 Squirrel-cage induction motors
          • 1.7.1.2.1 High efficiency motors
        • 1.7.1.3 Influence of the voltage across the windings
        • 1.7.1.4 Performance of squirrel-cage induction motors with changing frequency
  • 2 Switching tasks and selecting the appropriate switchgear
    • 2.1 Electrical equipment complying with standards and matching the application requirements
    • 2.2 Basic switching tasks and criteria for device selection
      • 2.2.1 Device types
        • 2.2.1.1 Disconnectors (isolating switches)
        • 2.2.1.2 Load switches
        • 2.2.1.3 Switch disconnectors
        • 2.2.1.4 Circuit breakers
        • 2.2.1.5 Supply disconnecting devices
        • 2.2.1.6 Supply disconnecting EMERGENCY STOP devices
        • 2.2.1.7 Summary supply disconnect and EMERGENCY STOP devices
        • 2.2.1.8 Fuses
        • 2.2.1.9 Devices for thermal protection
        • 2.2.1.10 Contactors
    • 2.3 Parameters for the correct selection and sizing
      • 2.3.1 Rated isolation voltage Ui
      • 2.3.2 Rated operational voltage Ue, rated operational current Ie and utilization category
      • 2.3.3 Rated impulse withstand voltage Uimp
      • 2.3.4 Short-circuit withstand capacity and short-circuit protection
        • 2.3.4.1 Joule integral I2t
        • 2.3.4.2 Cut-off current ID
        • 2.3.4.3 Rated short-time withstand current lCW
        • 2.3.4.4 Current limiting protective equipment
        • 2.3.4.5 Coordination of electrical equipment
          • 2.3.4.5.1 Coordination in respect of the switching capacity of the contactor (overcurrent selectivity)
          • 2.3.4.5.2 Coordination with respect to the operability after a short-circuit
        • 2.3.4.6 Short-circuit switching capacity
          • 2.3.4.6.1 Rated short-circuit making capacity Icm
          • 2.3.4.6.2 Rated short-circuit breaking capacity Icu and Ics
      • 2.3.5 Thermal protection
        • 2.3.5.1 Ambient temperature
        • 2.3.5.2 Operational overcurrents, heavy-duty starting
      • 2.3.6 Life span
        • 2.3.6.1 Prospective service life
        • 2.3.6.2 Mechanical life span
        • 2.3.6.3 Electrical life span
      • 2.3.7 Intermittent and short-time duty, permissible frequency of operation
        • 2.3.7.1 Intermittent duty and relative ON-time
      • 2.3.8 Rated frequency and harmonics
      • 2.3.9 Safety clearances
      • 2.3.10 Mounting position
      • 2.3.11 Protective separation
      • 2.3.12 Site altitude
      • 2.3.13 Shock and vibration
    • 2.4 Specific application conditions and switching tasks
      • 2.4.1 Parallel and series connection of poles
        • 2.4.1.1 Parallelling
        • 2.4.1.2 Series connection
      • 2.4.2 AC switchgear in DC applications
      • 2.4.3 Applications at supply frequencies < 50 Hz and > 60 Hz. Effect of harmonics
        • 2.4.3.1 Effect of the supply frequency on the thermal load
        • 2.4.3.2 Effect of the supply frequency on the switching capacity
        • 2.4.3.3 Performance of release units at supply frequencies < 50 Hz and > 60 Hz
        • 2.4.3.4 Switchgear used with soft starters
        • 2.4.3.5 Switchgear for use with frequency converters (inverters)
      • 2.4.4 Application of four-pole switchgear devices
        • 2.4.4.1 Applications of switchgear with 4 NO contacts
        • 2.4.4.2 Applications of switchgear with 2 NO and 2 NC contacts
        • 2.4.4.3 Applications of switchgear with 3 NO and 1 NC contact
      • 2.4.5 Application of circuit breakers in IT networks
      • 2.4.6 Switchgear for safety applications
        • 2.4.6.1 Mechanically linked contacts
        • 2.4.6.2 Mirror Contacts
      • 2.4.7 Installations in hazardous atmospheres
        • 2.4.7.1 History, guidelines and regulations
        • 2.4.7.2 Classification of hazardous areas
        • 2.4.7.3 Motors for hazardous areas
        • 2.4.7.4 Protection of motors of ignition protection type Increased Safety “e”
        • 2.4.7.5 ATEX 100a (Directive 94/9/EC)
        • 2.4.7.6 IECEx and other approval schemes for hazardous areas
  • 3 Starting and switching motors
    • 3.1 Selection criteria
    • 3.2 Direct starting of squirrel-cage induction motors
      • 3.2.1 Starting time
      • 3.2.2 Reversing starters
    • 3.3 Star-delta (Y-Δ, wye-delta) starting
      • 3.3.1 Normal star-delta starting
      • 3.3.2 Motor connection for clockwise and counterclockwise direction of rotation
      • 3.3.3 Influence of the third harmonic on motor protection relays
      • 3.3.4 Uninterrupted star-delta starting (closed transition)
      • 3.3.5 Amplified star-delta starting
      • 3.3.6 Part-winding star-delta starting
    • 3.4 Auto-transformer starting
      • 3.4.1 Circuit and function
      • 3.4.2 Rating of the starter
    • 3.5 Starting via chokes or resistors
      • 3.5.1 Starting via chokes
      • 3.5.2 Starting via resistors
    • 3.6 Stator resistance soft starting
      • 3.6.1 Circuit and function
    • 3.7 Pole-changing motors
      • 3.7.1 Speed change by pole changing
      • 3.7.2 Ratings of starters for pole changing
      • 3.7.3 Rating of the starter for steps with star-delta starting
    • 3.8 Starting wound-rotor motors
    • 3.9 Electronic soft starters
      • 3.9.1 Voltage ramp versus current limitation
      • 3.9.2 Voltage ramp
      • 3.9.3 Kickstart
      • 3.9.4 Current limitation
      • 3.9.5 Soft stop
      • 3.9.6 Soft starters for pump controls
      • 3.9.7 Motor braking
      • 3.9.8 Positioning speed and controlled braking
      • 3.9.9 Linear acceleration and deceleration by speed feedback
      • 3.9.10 Direct start with full voltage
    • 3.10 Frequency converters
      • 3.10.1 Principle of operation
        • 3.10.1.1 Rectifier
        • 3.10.1.2 Intermediate circuit
        • 3.10.1.3 Inverter
      • 3.10.2 Operational performance
      • 3.10.3 Change of sense of rotation and braking
      • 3.10.4 Motor protection
  • 4 Protection
    • 4.1 Protection requirements
      • 4.1.1 Protection against electric shock
        • 4.1.1.1 Protection against direct contact
        • 4.1.1.2 Protection against indirect contact
        • 4.1.1.3 Complementary protection
      • 4.1.2 Protection against overload and excess temperature
        • 4.1.2.1 Different loading curves of various kinds of electrical equipment
        • 4.1.2.2 Protection in continuous duty and at transient loads
        • 4.1.2.3 Overload and overtemperature protection by measurement of current and measurement of temperature
        • 4.1.2.4 Protective functions
          • 4.1.2.4.1 Protection during starting, monitoring of starting time, start interlocking
          • 4.1.2.4.2 Asymmetry protection
          • 4.1.2.4.3 Phase failure protection
          • 4.1.2.4.4 Stalling protection
          • 4.1.2.4.5 Underload protection
          • 4.1.2.4.6 Automatic switching-over during start-up
          • 4.1.2.4.7 Ground fault protection
        • 4.1.2.5 Display, warning and control functions
      • 4.1.3 Protection against high overcurrents, short-circuit protection
        • 4.1.3.1 Definition and characteristic of a short-circuit
        • 4.1.3.2 Effects of and dangers in case of short-circuits
        • 4.1.3.3 Protection requirements
          • 4.1.3.3.1 Switching capacity
          • 4.1.3.3.2 Current limitation
          • 4.1.3.3.3 Selectivity
          • 4.1.3.3.4 Short-circuit coordination
    • 4.2 Protective devices
      • 4.2.1 Fuses
        • 4.2.1.1 Principle of operation
          • 4.2.1.1.1 Current limitation
          • 4.2.1.1.2 Breaking capacity
        • 4.2.1.2 Standards and utilization categories
          • 4.2.1.2.1 Classification and time/current zones
        • 4.2.1.3 Designs
      • 4.2.2 Circuit breakers
        • 4.2.2.1 Principle of operation and design
        • 4.2.2.2 Standards, functions and utilization categories
          • 4.2.2.2.1 Standards
          • 4.2.2.2.2 Functions and utilization categories
        • 4.2.2.3 Design of a circuit breaker
          • 4.2.2.3.1 Thermal overcurrent releases
          • 4.2.2.3.2 Electromagnetic overcurrent releases
          • 4.2.2.3.3 Main contact system and switching capacity
        • 4.2.2.4 Application of circuit breakers
          • 4.2.2.4.1 Application as circuit breaker
        • 4.2.2.5 Installation of circuit breakers, safety clearances
      • 4.2.3 Miniature Circuit Breakers MCB
        • 4.2.3.1 Principle of operation and design
        • 4.2.3.2 Standards, tripping characteristics and rated switching capacity
        • 4.2.3.3 Installation of Miniature Circuit Breakers, safety clearances
      • 4.2.4 Motor protection relays (overload relays)
        • 4.2.4.1 Thermal motor protection relays
        • 4.2.4.2 Electronic motor protection relays
          • 4.2.4.2.1 Principle of operation
        • 4.2.4.3 Thermistor protection relays
          • 4.2.4.3.1 Relays for PTC sensors
          • 4.2.4.3.2 Relays for NTC sensors
          • 4.2.4.3.3 Metal resistance sensors
  • 5 Control circuits
    • 5.1 Utilization categories
    • 5.2 Control voltages
      • 5.2.1 Alternating voltage
        • 5.2.1.1 Control transformers for contactor controls
        • 5.2.1.2 Frequencies < 50 Hz and > 60 Hz
      • 5.2.2 Direct voltage
    • 5.3 Switching contactors
      • 5.3.1 Alternating current magnets
        • 5.3.1.1 Conventional alternating current magnets
        • 5.3.1.2 Electronic coil control
      • 5.3.2 Direct current drives
        • 5.3.2.1 “Conventional”
        • 5.3.2.2 Double winding coils
        • 5.3.2.3 Electronic coil control
      • 5.3.3 Electromagnetic compatibility and protective circuits
        • 5.3.3.1 Protective circuits in coil circuits
      • 5.3.4 Effect of long control lines
        • 5.3.4.1 Voltage drop
        • 5.3.4.2 Effect of the cable capacitance
      • 5.3.5 Contact reliability
  • 6 Considerations when building control systems and switchgear assemblies
    • 6.1 Temperature rise
      • 6.1.1 Temperature rise limit values
      • 6.1.2 Laboratory test conditions and real practical environment
      • 6.1.3 Verification of temperature-rise
      • 6.1.4 Important aspects regarding device temperature rise; Recommendations
        • 6.1.4.1 Rated current
        • 6.1.4.2 Thermal protective devices
        • 6.1.4.3 Conductor cross sections
        • 6.1.4.4 Conductor length
        • 6.1.4.5 Tightening torques
        • 6.1.4.6 Line ducting
        • 6.1.4.7 Operating frequency and harmonics
        • 6.1.4.8 Mounting devices side-by-side
        • 6.1.4.9 Mounting position
      • 6.1.5 Thermal imaging cameras
    • 6.2 Short-circuit withstand capacity