Reliance Controls Non-Metallic Power Inlet Box, Amps 50 - Outdoor

Our review of the Reliance Controls Non-Metallic Power Inlet Box, Amps 50 finds it best suited to homeowners who run a portable generator and need a safe, permanent outdoor inlet. The bottom line: this inlet box keeps the generator plug and wiring outside, reducing the risk of exhaust fumes entering the living space while offering generous wiring room and a raintight, non-metallic cabinet. Installation is straightforward for anyone comfortable with basic outdoor electrical work and makes connecting a 50-amp, up-to-12,500-watt generator far neater and safer than running cords through doors or windows.

Key Features

• NEMA 3R cabinet: The weatherproof rating means the inlet box is designed to withstand outdoor exposure while protecting the connection from rain and snow.
• Non-metallic construction: The durable, non-metallic housing resists corrosion and provides a lighter, easier-to-handle alternative to metal boxes.
• Designed for up to 12,500 watts: Sized specifically to accept generators with a maximum running wattage of 12,500, so it supports common 50-amp generator setups.
• Multiple knockouts: Four combination 1/2-in and 3/4-in knockouts (one on each side, bottom and back) allow flexible conduit or cable entry and simplify routing to a transfer switch or panel.
• Removable face for wiring: The front face removes to provide generous wiring space and easier rough-in during installation, reducing time on the ladder or scaffold.

Who It's For

This inlet box is ideal for homeowners and small property owners who use a portable generator for backup power and want a permanent, code-friendly feed point outside the structure. It suits users who plan to hardwire the inlet directly to a transfer switch or panel, eliminating temporary indoor cord runs and improving safety.

It is not targeted at industrial installations or applications needing a metal enclosure for specific local code requirements, nor is it intended for generators that require specialized inlet types beyond a standard 50-amp feed. Those with unusual wiring needs should consult an electrician before purchase.

Pros & Cons

Pros

• Well-built, raintight NEMA 3R cabinet that stands up to outdoor conditions.
• Plenty of wiring room and a removable faceplate make connections and rough-in easier.
• Includes combination knockouts for flexible conduit and cable routing to the transfer switch.
• Non-metallic construction avoids corrosion and reduces weight for handling and installation.

Cons

• Non-metallic housing may not meet every local code that prefers metal enclosures in certain installations.
• Requires competent electrical wiring to hardwire to a transfer switch or panel; not a plug-and-play indoor solution.

Specifications

Brand	Reliance Controls
Model	PBN50 (50-Amp inlet)
Cabinet type	NEMA 3R
Construction	Durable, non-metallic, raintight
Generator capacity	Up to 12,500 maximum running watts
Knockouts	Four combination 1/2-in and 3/4-in (sides, bottom, back)

Our Verdict

The Reliance Controls 50-amp non-metallic inlet box is a practical, value-minded choice for anyone installing a permanent outdoor feed for a portable generator up to 12,500 running watts. It offers solid weather protection, ample wiring room, and flexible knockouts that simplify routing to a transfer switch or panel, making it a smart upgrade from running cords through doors or windows.

Frequently Asked Questions

Can this be used outdoors?
Yes. The unit is rated NEMA 3R and is built to be raintight for outdoor installation.

Will it accept 6/3 w/ground Romex?
Customers report there is ample wiring room and it has worked for 6/3 w/ground Romex when run properly to a transfer switch.

How does the inlet connect to the transfer switch?
The box includes combination knockouts for conduit or cable entry and is designed to be hardwired through an outside wall directly to the transfer switch or panel.