NEMA ICS 18:2001 (R2007)

Foreword
1 GENERAL
  1.1 Referenced Standards
  1.2 Scope
  1.3 Normative References
  1.4 Equipment
2 DEFINITIONS
3 CLASSIFICATIONS
  3.1 Classes and Types
  3.2 Classes of Motor Control Centers
      3.2.1 Class I-Independent Units
      3.2.2 Class II-Interconnected Units
      3.2.3 Class I-S & II-S-Motor Control Centres with
             Custom Drawing Requirements
  3.3 Circuit Wiring
      3.3.1 Types of Wiring
4 CHARACTERISTICS AND RATINGS
  4.1 Voltage Ratings
  4.2 Combination Motor-Control Unit Ratings
  4.3 Continuous-Current Ratings of Buses
  4.4 Basis for Short-Circuit Current Rating of Motor Control
      Centres
      4.4.1 Available Short-Circuit Current
      4.4.2 Series Combination Rating
  4.5 Standard Short-Circuit Ratings of Motor Control Centres
      4.5.1 Ratings of Combination Motor-Control Unit and
             Feeder-Tap Units
      4.5.2 Units Not Containing a Short-Circuit Protective
             Device
      4.5.3 Separately Derived Systems
      4.5.4 Rating of Bus Structure
  4.6 Range of Operating Voltage
5 PRODUCT MARKING, INSTALLATION AND MAINTENANCE INFORMATION
  5.1 Preventive Maintenance
  5.2 Handling, Installation, Operation, and Maintenance
  5.3 Marking and Labelling
      5.3.1 Units
      5.3.2 Section(s)
      5.3.3 Marking Exception
6 SERVICE AND STORAGE CONDITIONS
7 CONSTRUCTION
  7.1 Vertical Section
  7.2 Wiring Space
  7.3 Unit Mounting
  7.4 Interlocking of Doors
  7.5 Spacings
  7.6 Control Circuit Protection
  7.7 Lighting Panel and Auxiliary Control Panel Protection
8 PERFORMANCE REQUIREMENTS AND TESTS
  8.1 Design Test Concept
  8.2 Test Methods
  8.3 Horizontal Common Power Bus and Vertical Extension
      Short-Circuit Withstand Test
      8.3.1 Tests
      8.3.2 Performance Criteria
  8.4 Combination Motor-Control Units and Feeder-Tap Units
      Short-Circuit Interrupting Tests
      8.4.1 Tests
      8.4.2 Performance Criteria
      8.4.3 Location of Units
      8.4.4 Unit Fault Connection
      8.4.5 Enclosure Ground Circuit
      8.4.6 Test Voltage and Frequency
      8.4.7 Test Current
      8.4.8 Test Circuit Calibration
      8.4.9 Test Duty Cycle
      8.4.10 Performance Rise Test
9 APPLICATION
  9.1 Technical Information Needed to Supply a Motor Control
      Center
  9.2 Application of Short-Circuit Current Ratings

Applies to three phase 50 and 60 hertz motor control centers rated not more than 600 volts AC.