# GFCI Protection > A safety device that instantly cuts power when it detects current leaking to ground — preventing electrocution. Required by code for outdoor, bathroom, kitchen, and pool/spa lighting circuits. **Source:** A GFCI monitors the current flowing out on the hot wire and returning on the neutral wire. If those two values differ by more than about 5 milliamps — meaning some current is "leaking" through an unintended path (like through a person) — the GFCI trips in less than 1/40th of a second, cutting power before the shock can cause injury. US electrical code (NEC) requires GFCI protection for lighting circuits in wet or damp locations: bathrooms, kitchens (within 6 feet of a sink), garages, outdoors, unfinished basements, crawl spaces, and near pools and spas. This applies regardless of voltage — even low-voltage pool lights need GFCI protection on the transformer's primary side. GFCI protection comes in two forms: GFCI outlets (the ones with Test/Reset buttons) that protect everything downstream, and GFCI breakers in the electrical panel that protect the entire circuit. For outdoor lighting, a GFCI breaker is often more practical since the fixtures may not have accessible outlets. If you're installing any outdoor or wet-area lighting, verify GFCI protection is in place before energizing the circuit. ## Specifications | Spec | Value | | --- | --- | | Response time | < 1/40th of a second | | Required for | Outdoor, bathroom, kitchen, pool, garage | | Types | GFCI outlet or GFCI circuit breaker | ## Related Terms - [IP Rating](https://ledlightinginfo.com/glossary/ip-rating.md) — Ingress Protection rating — a two-digit code indicating resistance to dust (first digit, 0-6) and water (second digit, 0-9). Higher numbers mean better protection. - [Low Voltage Lighting](https://ledlightinginfo.com/glossary/low-voltage-lighting.md) — Lighting systems that operate on 12V or 24V instead of mains voltage (120V/240V). Common in landscape lighting and LED strips — safer to install and requires a transformer.