What is the difference between an auto and a manual GFCI?
An auto GFCI energizes automatically when plugged in, requiring no button press. A manual GFCI requires the operator to press the RESET button to power up the unit before it will supply protected voltage. Both types require a manual RESET button press after any fault trip.
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 serves two roles: (1) Power-up — press RESET to close the relay and energize the load side when the unit is first connected to a voltage source; and (2) Fault reset — press RESET to restore power after a ground fault has tripped the unit. The operator must press RESET before the unit will supply protected voltage. (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 fault trip, both auto and manual GFCIs require the operator to press the RESET button to restore power. GFCIs are never designed to reset themselves automatically.
CAUTION: Only press the RESET button after the cause of the fault has been identified and repaired. Never reset a GFCI without first investigating the fault. GFCIs cannot, nor are ever designed to reset themselves automatically.
