These simple terms refer to the operation of the GFCI when first plugged into a voltage source.......
The GFCI terms “auto” and “manual” have been in the electrical industry for years. These simple terms refer to the operation of the GFCI when first plugged into a voltage source. These terms have nothing to do with the “tripping and subsequent resetting” of the GFCI.
Separate the two main events for a GFCI: (1) Power up mode and (2) Trip and Reset Mode. Power up mode is the condition of the GFCI after being plugged into a correct voltage source.
AUTO - The “auto” GFCI will immediately energize the relay and allow protected voltage to be available at the “load” side of the GFCI. The GFCI has automatically powered up and is ready for use without the assistance of the human pressing any buttons. Think plug-n-play.
MANUAL - On the “manual” GFCI, the RESET button has a dual role in functionality. (1)Powering up the unit and (2)resetting after a fault. The “manual” GFCI operates slightly different in that it requires the human to press the “RESET” (which is operating as a power up button on this unit) so the GFCI can close the relay and operate as required.
RESET - After a “trip” situation, both styles of GFCI require the pressing of the reset button to re-start the GFCI.
CAUTION: Only reset a GFCI after an investigation as to the fault cause has been identified and repaired. GFCIs cannot, nor are ever designed to reset themselves automatically.
