Outdoor Generator Inlet Boxes

Match the inlet box amperage and plug type to your generator and transfer switch (common ratings are 30A or 50A and 120/240V), confirm NEMA connector compatibility, and choose a weatherproof, outdoor-rated enclosure with tamper-resistant features if it will be exposed to the elements

Look for corrosion-resistant materials such as stainless steel or UV-stabilized thermoplastic and an outdoor weather rating (e.g., NEMA 3R or higher) to ensure protection from rain, snow, and sunlight; gaskets and stainless fasteners improve long-term durability

Inlet boxes are specified by amperage and NEMA configuration (for example, 30A 125V single-phase or 50A 125/250V 3-prong/4-prong), so check your generator’s outlet plug and your transfer switch receptacle to ensure the inlet uses the matching NEMA number

Ensure installation follows electrical code and is performed or inspected by a qualified electrician; important features include lockable covers, clearly labeled grounding, strain relief for conduit or cord, and proper mounting height and location away from flood-prone areas

Outdoor generator inlet boxes commonly range from budget options under $50 to higher-end models over $150, with average prices around $80; lower-cost units may use less durable plastics or fewer weatherproofing details, while higher-priced boxes typically offer metal construction, better sealing, and added security

Periodically inspect seals and fasteners, clean debris from the cover and inlet, apply silicone grease to gaskets if recommended, and replace corroded components to maintain weatherproofing and electrical connections

Yes—many inlet boxes are suitable for temporary corded generator use and permanent standby connections, but permanent installations should use appropriately rated inlets integrated with a transfer switch and meet local code and permit requirements