An Overview of Power Distribution Equipment Standards: UL 891, UL 1558, and UL 1008


It is important for users to understand the difference between the types of power distribution equipment in order to properly specify, apply, and install the equipment. This course provides an overview of power distribution standards including UL 891 Switchboards, UL 1558 Metal-Enclosed Low-Voltage Power Circuit Breaker Switchgear, UL 1008 Transfer Switch Equipment, and other related standards including medium voltage. IEC and IEEE standards are also discussed. The course includes guidance on UL processes for evaluating and listing power distribution equipment, factory inspections, equipment modifications, and required field evaluations. The interconnection of various types of equipment, including the use of transfer switches for utility and distributed generation is discussed. Focus is also provided on required grounding and bonding of equipment, and the National Electric Code requirements for emergency, legally required, and optional standby power applications. A broad overview of arc flash considerations is also covered.


Upon completion of this course, you should be able to:

  • Describe UL processes, listing, and evaluation of power distribution equipment
  • Differentiate the standards applicable to specific types of power distribution equipment
  • Identify common requirements for power distribution equipment
  • Describe the difference between US and IEC standards for power distribution equipment
  • Explain grounding and bonding requirements for service equipment
  • Differentiate emergency, legally required, and optional standby applications
  • Define arc flash, its possible causes, and means of personnel protection against it

Target Audience

  • Consultants
  • Equipment users
  • Equipment manufacturers
  • Authorities Having Jurisdiction
  • Design Engineers

Continuing Education Units (CEUs)

  • 0.7 IACET CEUs; contact your local jurisdiction for CEU recognition.
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Time Requirement


Instructor-Led 1 day $450.00

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