Reliance Controls PB50 50-Amp Power Inlet Box Gray — NEMA 3R Weatherproof, Hardwire for 12,500W Generators

The Reliance Controls PB50 is a weatherproof 50-amp power inlet box built to hardwire a portable generator to your home's transfer switch safely and without running cords through doors or windows.

When you plan to connect a portable generator to a transfer switch or manual transfer panel, the PB50 inlet box gives you a clean, code-friendly outdoor connection point. Made for exterior mounting, this NEMA 3R enclosure resists rust and moisture, offers roomy wiring space for easier installation, and uses standard knockouts so electricians can route feed conductors directly to the transfer equipment. It’s a practical accessory for homeowners and electricians who need a durable inlet rated for up to 50 amps and generators up to 12,500 running watts.

How does the PB50 keep outdoor connections safe?

The PB50 is built with a weather-resistant enclosure, a spring-loaded inlet cap, and corrosion-resistant powder coat to protect the inlet when it’s not in use. Its design prevents rain and splash from reaching live connections while providing a secure, sealed connection during operation.

• Raintight NEMA 3R enclosure for outdoor mounting
• Spring-loaded inlet cap reduces moisture entry
• Durable steel construction with anti-corrosive finish
• Faceplate removable for protected wiring access

What wiring and electrical limits should I expect?

This inlet handles up to 50 amps at 125/250 VAC and is intended for use with 8 AWG conductors rated 75°C. It supports portable generators with running wattage up to approximately 12,500 watts when matched with an appropriate transfer switch or load center.

• Maximum generator input: 50A @ 125/250VAC
• Maximum recommended generator running watts: 12,500
• Use with 8 AWG, 75°C insulated wire per installation guidance
• Compatible with designated Reliance transfer switches and panels

How does this simplify installation for electricians and homeowners?

The PB50 includes four combination 1/2" and 3/4" knockouts located on each side, bottom and back, which makes routing conduit or cable straightforward. The removable face and roomy interior ease rough-in wiring and permit straightforward final connections to the transfer switch or panel inside the building.

• Four combo knockouts for flexible conduit or cable entry
• Removable face for easy access during rough-in and final wiring
• Generous internal wiring space for neat, code-compliant terminations
• Designed for hardwiring directly to transfer switches or panels

What approvals and support does Reliance provide?

The PB50 is manufactured by Reliance Controls, a long-established company specializing in generator accessories and transfer equipment. The unit carries recognized safety listings and a limited warranty to back its construction and performance expectations.

• cUL listing for safety and performance compliance
• Five-year limited warranty from Reliance Controls
• Industry experience and product support from a century-old manufacturer

Who should consider the PB50? If you want a code-friendly, outdoor inlet for a portable generator—eliminating extension cords through doors and windows—the PB50 is aimed at homeowners, electricians, and contractors installing manual transfer switches or generator-ready load centers. It’s best for setups that require a weatherproof, hardwired connection rated for 50 amps and up to roughly 12,500 running watts. For exact compatibility and safe installation, pair it with the appropriate Reliance transfer switch and follow local electrical codes and an electrician’s guidance.