Product Overview

The Pentair Amerlite® 78458100 Underwater Pool Light is a professional-grade 120V, 500-watt incandescent pool light featuring a 50-foot factory cord, stainless-steel shell, stainless-steel face ring, and Pentair’s prismatic tempered-glass lens.

Amerlite has long been used in residential swimming pools where dependable, high-output white underwater illumination is required. The prismatic lens is designed to help diffuse light throughout the pool, while the stainless-steel face ring uses Pentair’s uni-tension clamp design for secure assembly.

Pentair currently identifies 78458100 as the 500W / 120V Amerlite with stainless-steel face ring and 50' cord.

Key Features

Genuine Pentair Amerlite®

Manufacturer Part Number: 78458100

120-volt operation

500-watt incandescent light

50-foot factory cord

Bright white underwater illumination

Stainless-steel shell

Stainless-steel face ring

Pentair uni-tension clamp

8-3/8" prismatic tempered-glass lens

Designed for superior underwater light diffusion

Low-water cutoff design

Compatible with select full-size Pentair, American, PacFab and Purex niches

Suitable for residential inground swimming pools

Genuine Pentair replacement light assembly

Pentair specifies the Amerlite family with an 8-3/8" prismatic tempered-glass lens and stainless-steel construction.

Bright 500-Watt Incandescent Illumination

The 500-watt incandescent bulb provides the traditional bright white illumination associated with classic underwater pool lighting.

This model is an excellent replacement when maintaining an existing Amerlite installation where the homeowner wants to keep the original incandescent lighting system rather than convert to LED.

Prismatic Tempered-Glass Lens

The Amerlite uses a prismatic tempered-glass lens designed to distribute and diffuse light throughout the swimming pool.

Pentair lists an 8-3/8-inch lens on the Amerlite assembly.

Stainless-Steel Face Ring

The light features a stainless-steel face ring for durability in underwater applications.

The uni-tension clamp secures the face-ring and lens assembly while helping maintain proper compression around the fixture.

50-Foot Cord

The 78458100 includes a 50-foot factory-installed cord, making it appropriate for equipment layouts where the light junction box can be reached within the supplied cord length.

Pentair also manufactures other Amerlite configurations with longer cords, so verify the required distance before ordering.

Specifications

The 50-foot cord, 500-watt rating, 120V configuration and UPC are listed for part 78458100.

Warranty & Compatibility

Designed for Full-Size Pentair Niches

Pentair states that Amerlite lights are UL listed for installation in compatible full-size:

• Pentair Pool Products niches
• American Products niches
• PacFab niches
• Purex niches

Always verify the existing niche model, voltage and electrical configuration before purchasing a replacement underwater light.

Saltwater Compatibility

Pentair states that its UL-listed underwater lights are certified for use in fresh water with salinity levels up to 6,000 ppm.

Important Electrical Information

This is a 120V underwater pool light.

Pentair specifies that 120V pool and spa lights must be connected to a properly protected electrical circuit, including appropriate GFCI protection. Installation should comply with applicable electrical codes and should be performed by a qualified pool professional or electrician.

Customer-Facing Q&A

Q: What is Pentair 78458100?
A: 78458100 is a Pentair Amerlite underwater incandescent pool light rated at 120V, 500W with a 50-foot cord.

Q: Does 78458100 have a stainless-steel face ring?
A: Yes. This model includes the stainless-steel face ring with Pentair's uni-tension clamp.

Q: What color light does it produce?
A: It produces traditional white incandescent pool lighting.

Q: How long is the cord?
A: 50 feet.

Q: What voltage is it?
A: 120 volts.

Q: What wattage is the bulb?
A: 500 watts.

Q: Does it include the complete light assembly?
A: Yes. This is the complete Amerlite underwater light fixture assembly with factory cord, stainless-steel shell, face ring, lens and incandescent lighting components.

Q: Does it include the pool niche?
A: No. The underwater niche is sold separately.

Q: What size is the Amerlite lens?
A: Pentair specifies an approximately 8-3/8" prismatic tempered-glass lens.

Q: Will it replace an older Amerlite?
A: It is commonly used as a replacement for compatible full-size Amerlite installations, but you should verify voltage, cord length and niche compatibility before ordering.

Q: Can it be used in a saltwater pool?
A: Pentair states its UL-listed underwater lights are certified for water with salinity up to 6,000 ppm.

Q: Can I replace a 400W Amerlite with this 500W version?
A: Do not increase fixture wattage without verifying that the existing fixture, niche and electrical system are approved for the configuration. For a direct replacement, matching the original Pentair model and electrical specifications is preferred.