I re-learned some electrical terms today that may be useful later when working with GFCI circuits.

  • Line (usually black, also known as “hot”): comes in from the electrical panel
  • Load (usually black, sometimes red): is a continuation of line and goes out to downstream devices. Non-GFCI circuits will not have a load.
  • Neutral (usually white): completes the AC circuit and carries excess current to ground
  • Ground (bare): carries any inadvertent current away from the circuit in case of a fault

The catchphrase is “line in, load out”.

GFCI devices have a built-in breaker that will disconnect both the hot and neutral circuits (hence the reason for the load terminal and the oft built-in neutral pigtail) when the current varies between hot and neutral (indicating a fault) by more than 3–6mA. GFCIs are neat.