Where should a GFCI be installed and what can it protect?

• A. It should be installed in a readily accessible location and may be used to protect feeders.
• B. It must be installed at the main service cabinet only.
• C. It must be installed inside a locked equipment panel.
• D. It cannot be used to protect feeders.

Answer: (A)

A GFCI should be placed in a readily accessible location so you can test and reset it easily, which is essential for verifying protection and quickly clearing a fault. It monitors the current in the hot and neutral conductors and trips if there’s an imbalance, which helps prevent shock.

Because of how GFCIs work, any conductors fed from the device on its load side are protected. That means downstream feeders can be protected by the same GFCI if they’re wired through the GFCI’s load terminals. You’re not limited to the main service cabinet; you can install a GFCI at convenient points along the circuit, as long as the upstream device supplies the protected load side and the location is accessible.

It shouldn’t be buried inside a locked panel, since accessibility is required for testing and resetting. The idea that a GFCI must be at the main cabinet or that it can’t protect feeders isn’t correct, because protection can extend to downstream feeders when wired through the GFCI.