Electrical Protection and Grounding Training

418-01 Electrical Faults and Current Ratings

When you complete this lesson, you will be able to explain causes and types of electrical overcurrent, and identify how to protect circuits from overcurrents and faults.

  • Describe an electrical overcurrent condition
  • Describe an electrical fault with excessively high current flow
  • Identify the difference between an electrical circuit overload condition and a short circuit condition
  • Name two good conductors of electricity
  • List some of the factors that determine the current rating of a conductor
  • Explain how devices are used to protect from overcurrent and faults
  • Describe ground faults that can occur from various grounding connections

418-02 Overcurrent Protection, Fuses, and Breakers

When you complete this lesson, you will be able to identify types of fuses and breakers used in electrical distribution systems and explain how they work.

  • Compare single element and dual element fuses
  • Explain the difference between an overload and a short circuit
  • Identify one main difference between a fuse and a breaker
  • Describe how current limiting fuses and breakers can limit the fault current
  • Discuss selective coordination for fuses and breakers

418-03 Protective Relays

When you complete this lesson, you will be able to identify protection relay elements on an electrical drawing according to their ANSI (American National Standards Institute) standard device numbers. In addition, you will be able to describe basic relay operations and compare the accuracy and options provided by commonly used relays.

  • Describe the operating principles behind protective relays
  • Identify the essential requirements of relay protection
  • List the ANSI standard device-function numbers that identify relays
  • Describe the two types of electromechanical relays
  • Discuss the benefits of solid-state relays

418-04 Generator, Transformer, and Motor Protection

When you complete this lesson, you will understand the principles of operation governing ground fault protection, phase-to-phase short circuit, time overcurrent protection, and motor overload protection.

  • Describe types of ground circuit connections for a generator
  • Compare the current flow for various types of generator ground connections
  • Describe the function of a differential current relay
  • Discuss the number of relays needed for three-phase, differential overcurrent protection
  • Identify resources that specify the level of overload protection that should be used for a motor
  • Describe how to choose overload protection for a three-phase motor

418-05 Grounding and Bonding

When you complete this lesson, you will be able to describe how grounding systems are used to ground electrical systems and equipment.

  • Identify the purpose of grounding electrical systems and equipment
  • Define the following terms as they relate to grounding:
    • Ground
    • Grounded conductor
    • System
    • Equipment
    • Ground fault
  • Distinguish between the three common types of grounding systems
  • Discuss the concepts of system grounding and equipment grounding
  • Describe how to apply the proper grounding methods for various applications