Intermatic K4121C Pho Stem Mount Thermal Photocontrol 120V

Product Description

The INTERMATIC K4121C PHO is a stem mount thermal photocontrol designed for dusk-to-dawn ON/OFF switching of outdoor lighting. Rated at 120 VAC and compatible with both 50 Hz and 60 Hz systems, this unit installs directly onto standard outdoor light fixtures and electrical boxes. The thermal sensing element responds to ambient light levels, automatically energizing connected fixtures at dusk and de-energizing them at dawn. Licensed electricians and lighting contractors install this control as a straightforward, self-contained solution for automating exterior lighting on residential and light commercial properties. The gray housing measures 3 inches tall by 1.563 inches wide and 1.563 inches deep.

This photocontrol is intended for outdoor lighting automation applications where a dedicated photocell switch is needed. It fits standard outdoor fixture stems and electrical boxes using a 0.5-inch 14 NPSM threaded connection or a 0.875-inch knockout hole. Typical installations include pole-mounted area lights, wall-pack fixtures, post lanterns, and similar exterior luminaires requiring automated dusk-to-dawn operation. It is suited for residential driveways, parking areas, building perimeters, and light commercial exterior lighting systems.

Key Features

• Dusk-to-dawn automatic ON/OFF control responds to ambient light levels without manual switching
• Rated 120 VAC at 50/60 Hz for compatibility with standard single-phase residential and light commercial circuits
• Stem mount design fits 0.5-inch 14 NPSM threaded fixture stems or 0.875-inch knockout openings
• Compact gray housing at 3 inches tall and 1.563 inches wide for low-profile installation
• 2-year limited warranty backed by INTERMATIC
• Manufactured in Mexico with country-of-origin documentation for project compliance

Compatibility

Designed for use with standard outdoor light fixtures and electrical boxes accepting a 0.5-inch 14 NPSM threaded stem mount or a 0.875-inch knockout hole, typical of residential and light commercial exterior luminaires.

Installation Notes

Installation should be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and applicable local codes. De-energize the circuit at the breaker and verify absence of voltage with a meter before handling any wiring or mounting hardware. Mount the photocontrol in a location with unobstructed exposure to natural sky light to ensure accurate dusk and dawn detection. Avoid positioning the unit where it will be exposed to artificial light sources that could cause false triggering or prevent the fixture from switching off at dawn.

Technical Specifications

• Input Voltage: 120 VAC, 50/60 Hz
• Height: 3 inches
• Width: 1.563 inches
• Depth: 1.563 inches
• Color: Gray
• Application: Outdoor Lighting Control
• Warranty: 2-Year Limited
• Country of Origin: Mexico

Standard Information

• Brand: INTERMATIC
• Manufacturer Part Number: K4121C PHO