Maricopa Community Colleges  ABA257   19974-20032 
Official Course Description: MCCCD Approval: 03/25/97
ABA257 19974-20032 LEC 1 Credit(s) 1 Period(s)
Specialty Transformers and Emergency Systems
Operation of specialty transformers. Harmonics and problem solving techniques. Operating principles of engine-driven generators and alternators. Manual and automatic transfer switches. National Electrical Code (NEC) requirements for standby emergency systems. Prerequisites: (Indentured status with the Arizona Builders Alliance) and ABC223 or permission of the apprenticeship coordinator.
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MCCCD Official Course Competencies:
 
ABA257   19974-20032 Specialty Transformers and Emergency Systems
1. List and define trade terms related to specialty transformers and standby and emergency systems. (I)
2. Identify and describe the operation of specialty transformers. (II)
3. Define harmonics and describe causal factors and problem solving techniques. (III)
4. Describe the basic operating principles of engine-driven standby generators. (IV)
5. Size and select standby emergency equipment for specific applications. (V)
6. Explain the operating principles of both manual and automatic transfer switches. (VI)
7. Describe installation, grounding and connecting procedures for standby emergency systems according to the National Electrical Code. (VII)
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MCCCD Official Course Outline:
 
ABA257   19974-20032 Specialty Transformers and Emergency Systems
    I. Terminology
        A. Autotransformer
        B. Bank
        C. Delta connection
        D. Harmonic
        E. Impedance
        F. Insulating transformer
        G. Transformer potential
        H. Legally required standby systems
        I. Polarity
        J. Rectifier
        K. Rheostat
        L. Solenoid
        M. Two-step voltage regulator
        N. Other
      II. Specialty Transformers
          A. Basic types
            1. Power
            2. Distribution
            3. Autotransformer
            4. Instrument transformer
            5. Potential
          B. Internal connections
          C. Special transformers
            1. Multi-secondaries
            2. Three-winding
            3. Autotransformers
            4. Zig-zag grounding
            5. Constant current
            6. Control
            7. Series
            8. Rectifier
            9. Reactors
            10. Step-voltage
          D. Instrument transformers
            1. Current
            2. Potential
          E. Buck and boost transformers
        III. Harmonics
            A. Definition
            B. Voltage harmonics
            C. Office building and plants
              1. Neutral conductors
              2. Circuit breakers
              3. Busbars and connecting lugs
              4. Electrical panels
              5. Telecommunications
              6. Transformers
              7. Generators
            D. Diagnosing harmonics problems
              1. Load inventory
              2. RMS (root-mean-square) meters
              3. Crest factor
            E. Solving harmonics problems
              1. Overloaded neutrals
              2. Derating transformers
          IV. Standby and Emergency Systems
              A. AC (alternating current) generators/alternators
                1. Alternating current
                2. Voltage control
                3. Load and power-factor regulation
              B. Engine-driven alternators
                1. Standby system parameters
                2. Cooling
                3. Load transfer switch
              C. Generator types
                1. Shunt field generator with commutator
                2. Shunt field generator with rheostat
                3. Compound generator-DC (direct current) only
                4. Compound generator - noncranking
                5. Shunt generators - series cranking
                6. DC generator with AC winding
              D. Factors in current generation
                1. Heat
                2. Eddy currents
                3. Armature reaction
                4. Commutating generators
              E. Revolving armature generators
                1. Electromagnetic fields
                2. AC generator producing DC
                3. AC generator excitation
                4. Voltage regulation
                5. Voltage regulators
              F. Revolving field generators
              G. Brushless generator and regulator
                1. Voltage wave shapes
                2. Magneciter excitation
                3. Exciter field excitation
                4. Amplifier circuit
            V. Sizing and Selecting Equipment - Exercise
                A. Applications
                B. Requirements
                C. Equipment selection
              VI. Transfer Switches
                  A. Manual
                  B. Automatic - sequential paralleling
                VII. NEC Requirements for Emergency Systems
                    A. NEC Article 700
                    B. NEC Article 250-6
                    C. Legally required standby systems (NEC Article 701)
                      1. Power sources
                      2. Storage batteries
                      3. Generator sets
                    D. Emergency system circuits for light and power
                      1. Health care facilities (NEC Section 517-3)
                      2. Places of assembly (NEC Article 518)
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