TT30

TT-30 is a NEMA electrical connector standard used for supplying shore power to recreational vehicles. It is a 120-volt, 30-amp connector, providing up to about 3,600 watts of power. The designation TT-30 is used for both the plug, TT-30P, and the corresponding receptacle, TT-30R.

Design and configuration: The TT-30 uses three conductors—hot, neutral, and ground—in a three-prong arrangement. It is designed for 120-volt service and is not compatible with higher-voltage NEMA configurations. The plug and receptacle are keyed to prevent incorrect mating, reducing the chance of incorrect connections in outdoor environments.

Usage: TT-30 outlets are common at RV parks and campgrounds for supplying shore power to travel trailers and many fifth-wheel trailers. RVs may rely on a TT-30 inlet on the unit or on a portable cord or power pedestal to connect to the grid. Many park pedestals also offer higher-capacity services, such as 50-amp NEMA 14-50 outlets, for RVs requiring more power, but TT-30 remains widespread for lower-power loads.

Safety and compatibility: Use cords rated for 30A with weatherproof, outdoor-rated connectors; ensure proper grounding and correct polarity; avoid adapters that defeat the 30A rating. For longer runs, use appropriately gauged cable to minimize voltage drop. Follow local electrical codes and campground guidelines to maintain safe operation.

History and status: The TT-30 standard was developed as part of NEMA’s family of RV power connectors and remains widely used in North America, particularly for mid-range RVs, since the late 20th century. It coexists with higher-capacity RV connectors such as NEMA 14-50 (50A, 240V) and is referenced in RV equipment manuals and campground infrastructure.