A power coupling was a component used aboard Federation starships during the 23rd and 24th centuries. (ENT: "United", "In a Mirror, Darkly, Part II"; TNG: "The Wounded", "Disaster")

In 2368, Crewman Terry of the USS Sutherland replaced several power couplings. (TNG: "Redemption II")

In 2374, on stardate 51186.2, Seven of Nine reached into a primary power coupling with her bare hand during construction of the USS Voyager's astrometrics laboratory. She was quickly warned by Ensign Harry Kim that such action should not be taken again as they were in direct violation of Starfleet safety protocols. (VOY: "Revulsion")

On many Federation ships, including Voyager, power couplings played a critical role in the discharge of phaser energy from the phaser array. Aboard Voyager in 2373, after the Kazon hijacking, the primary phaser coil was disabled by Tom Paris and the backup coil sabotaged by crewman Lon Suder. Suder rigged the computer to block the discharge from the backup phaser coil, causing it to overload when the Kazon pirates attempted to fire. Their sabotage was successful, doing massive damage to the biologicals on the bridge and otherwise disabling the ship. (VOY: "Basics, Part II")