CSLB C-10 Electrical ContractorSafety and TestingEasy

A qualified electrical worker needs to verify the proper operation of a ground-fault circuit interrupter (GFCI) receptacle after installation. Which of the following is the correct method to test a GFCI receptacle?

  1. AUse a multimeter to measure voltage between hot and ground.
  2. BApply a known fault current using a specialized GFCI tester.
  3. CPlug in a load and check if it operates.
  4. DPress the 'TEST' button and ensure the 'RESET' button pops out.
Show answer & explanation

Correct answer: D. Press the 'TEST' button and ensure the 'RESET' button pops out.

The most common and correct method to test a GFCI receptacle is to use its built-in 'TEST' button. Pressing this button simulates a ground fault, causing the internal breaker to trip and the 'RESET' button to pop out, indicating proper function. The GFCI should then be reset.

Why the other options are wrong

  • A. This measures voltage, not the GFCI's fault-sensing capability.
  • B. While specialized testers exist for advanced diagnostics, the built-in test button is the primary method for routine verification.
  • C. This only confirms power, not GFCI protection.

GFCI Test Procedure

To test a GFCI receptacle, press the 'TEST' button, which simulates a ground fault and should cause the GFCI to trip. Then, press the 'RESET' button to restore power, confirming its proper operation.

  • Built-in 'TEST' button simulates a ground fault.
  • Tripping indicates proper function.
  • Should be tested monthly and after installation/maintenance.
  • Always follow with a 'RESET' to restore power.

Memory trick: Test, Trip, Reset: The GFCI Safety Dance!

More Safety and Testing questions