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Washington Master Domestic Well (3A) License

The Master Domestic Well (3A) License allows you to do the following work:

  • Supervise electrical work and electricians on the following:
    • Extension of a branch circuit, which is supplied and installed by others
    • Signaling circuits
    • Motor control circuits
    • Motor control devices and pumps which do not exceed 7 1/2 horsepower at 250 volts AC single phase input power regardless of:
      • Motor controller output
      • Motor voltage/phase used in residential potable water
      • Residential sewage disposal systems
    • Work with Domestic water systems and public water systems including but not limited to:
      • Pumps
      • Pressurization
      • Filtration
      • Treatment
      • Other equipment and controls

How to Get the Master Domestic Well (3A) License in Washington?

  1. Meet the requirements for the certification level:
    • Be certified as an electrician for at least 2 years
  2. Gather the followinginformation before applying for the exam with PSI©:
    • Social Security Number
    • Mailing address
    • Email address
    • Corresponding fees
  3. Fill out the Application for Master Domestic Well (3A) Examination and send it, along with all the previous documents, to:
    Electrical Program
    PO Box 44460
    Olympia, WA 98504-4460
    The Washington State Department of Labor & Industries allows candidates to apply in person. Refer to the list of local offices before visiting
  4. Expect a response by mail from the Labor & Industries department along with instructions on scheduling the exam once the application has been reviewed
  5. Take and pass the master examination. For further information on the subjects and study material needed to prepare for the exam, refer to the Candidate Information Bulletin
  6. Complete a Change Assignment of Master Certificate form to be assigned as a designated master electrician to an electrical contractor and submit it with the corresponding fee

Washington Master Domestic Well (3A) License Exam Prep Courses

Washington Master Domestic Well (3A) License Exams

Below is all the information related to the trade and WA Codes exams, including the official reference lists.

Washington Master Domestic Well (3A) Trade Exam

  • Testing Method: Computer-based testing
  • Testing Company: PSI©
  • Number of Questions: 34
  • Types of Questions: Multiple choice
  • Time Allowed: 180 Minutes
  • Minimum Passing Score: 70%
  • Subjects Involved (No. of Questions):
    • NEC 90 - Introduction (1)
    • NEC 100-110 - General Requirements (1)
    • NEC 200-225, 280-285 - Wiring & Protection (2)
    • NEC 240 - Overcurrent Protection (4)
    • NEC 250 - Grounding & Bonding (4)
    • NEC 300-398 - Wiring Methods (6)
    • NEC 400-427, 455-480 - Electrical Equipment (2)
    • NEC 430-450 - Motors, HVAC, Generators & Transformers (5)
    • NEC 500-516 - Hazardous Locations (1)
    • NEC 705-780 - Special Conditions (1)
    • General Trade Knowledge & Theory (7)
  • PSI© Master Domestic Well (3A) Official Content Outline

Washington Master Domestic Well (3A) WA Codes Exam

  • Testing Method: Computer-based testing
  • Testing Company: PSI©
  • Number of Questions: 20
  • Types of Questions: Multiple choice
  • Time Allowed: 60 Minutes
  • Minimum Passing Score: 70%
  • Subjects Involved (No. of Questions):
    • Washington Laws & Rules (RCW & WAC) (20)
  • PSI© WA Codes Official Content Outline

Washington Master Domestic Well (3A) Book Set

This set of books includes all required references for the Master Domestic Well (3A) and WA Codes exams. Orders placed before 2 PM are shipped the same day via UPS and a tracking number is emailed before 3 PM.

  • WASHINGTON MASTER DOMESTIC WELL (3A) - BOOK SET WITHOUT TABS INCLUDES ALL BOOKS FOR TRADE AND BUSINESS EXAMS

    Sales price: $349.45

  • WASHINGTON MASTER DOMESTIC WELL (3A) - BOOK SET WITH TABS INCLUDES ALL BOOKS FOR TRADE AND BUSINESS EXAMS

    Sales price: $399.45

Washington Master Domestic Well (3A) Exam Books

Books Allowed in Testing

Washington Master Domestic Well (3A) WA Codes Exam Books

Books Allowed in Testing

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