Pentair 78310500 Brass Junction Box | 1/2" | 3 Port | For Lights

The Pentair 78310500 Brass Junction Box is a compact, professional-grade electrical housing built to meet NEC standards for pool and spa lighting systems. Featuring a corrosion-resistant brass base and impact-resistant polycarbonate lid, it accommodates up to three 1/2-inch conduits for organized wiring. This unit includes grounding terminals and a built-in cord strain relief for safe and efficient installations. Measuring just 5-3/8" x 3-5/8" at the top and 4-1/4" x 2-1/2" at the base, the box offers a discreet profile in deck or wall mounts, while the black finish seamlessly blends into the poolside environment.

Highlights

• Engineered for Pool Light Systems: Designed to house electrical connections safely in wet environments, suitable for Pentair pool and spa lighting configurations.

• Three-Port Conduit Access: Includes three 1/2" ports to streamline wiring for multiple fixtures, making installation easier for professional electricians.

• Durable, Outdoor-Ready Build: Combines a strong brass body with a weather-resistant polycarbonate lid, resisting UV, moisture, and corrosion.

• Meets NEC Standards: Pre-fitted with bonding and grounding terminals, plus cord strain relief for up to 10/3 AWG cables, ensuring code-compliant connections.

• Compact and Sleek Profile: Small footprint with a clean black exterior helps the junction box remain unobtrusive in landscaped or concrete decking.

Includes

• (1) Pentair 78310500 Brass Junction Box

Compatibility

• Pentair Pool and Spa Lights

Instructions

A. THE FOLLOWING PREPARATORY STEPS MUST BE COMPLETED BY THE CERTIFIED ELECTRICIAN BEFORE LIGHT IS INSTALLED
1. Ensure that the electrical system of your pool conforms with all requirements of the National Electrical Code (NEC),
and all local codes and ordinances. A licensed or certified electrician must install the electrical system to meet or
exceed those requirements before the Junction Box is installed. Some of the NEC requirements are listed below.
2. To be certain that the pool’s electrical system meets all applicable requirements, the electrician should
also consult the local building department.
3. Position Junction Box to meet National Electrical Code (NEC) requirements and to prevent hazard to personnel.

4. The center conduit hub is provided with a strain relief for a cord size up to a 10/3 AWG cord. Use underwater lights
with water resistant cord only.
5. Three equipment grounding terminals are provided for internal grounding suitable for #16 AWG to #10 AWG wire.
One pressure wire grounding terminal is provided for a #8 AWG insulated copper bonding wire.
6. Install the Junction Box gasket between the Junction Box base and cover. Replace gasket if worn or damaged (P/N
79300600).
7. Plug any unused conduit hubs with the conduit plugs provided.

Additional Info

Need to install or replace your pool lighting junction box? These FAQs cover everything you should know about the Pentair Brass Junction Box 78310500, including compatibility and local availability.

Code-Compliant Junction Box Setup

This junction box is NEC-compliant and suitable for pool and spa lighting systems. Install with care and follow safety protocols.

Is this box approved for outdoor pool installations?

Does it include plugs for unused conduit holes?

Can I check local pricing and stock at my nearest store?

Does it support bonding with a #8 AWG copper wire?

Will it work with a 10/3 AWG underwater light cord?

Features That Ensure Long-Term Safety

With a brass base and polycarbonate lid, this box is corrosion-resistant and weatherproof. It's designed to withstand tough pool environments.

Will this junction box rust over time?

Can I use this near saltwater pools?

Does it prevent water ingress when sealed properly?

What material is the included gasket made from?

How many grounding terminals are included?

Measuring Fitment for Your Pool Area

Compact and low-profile, this box fits into most lighting setups. Here's what to verify before installation.

What are the outer dimensions of the box top and base?

Can this be installed flush with decking or pavers?

Will the black finish blend with my backyard setup?

Can I bring my current box in to compare sizes?

Is this stocked year-round at pool supply stores?