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Description

The K4100 Series Photo Controls feature stem mounting, thermal-type, controls with single and multi-voltage models. Thermal-type photo controls provide dusk-to-dawn lighting control and a delay action, which eliminates loads switching OFF due to car headlights, and lighting. The thermal-type controls feature a cadmium sulfide photocell and a sonic-welded polycarbonate case and lens to seal out moisture. The design utilizes a dual temperature compensating bimetal and composite resistor for reliable long life operation over ambient temperature extremes. These models are California Title 24 compliant.

Specifications

Dimensions

Length/Depth
1.57 in
Width/Diameter
1.57 in
Height
3 in
Weight
0.24 lb

Documents

Style & Materials

Material
Metal
Mounting Type
Fixture mount

Characteristics & Features

Sensor Technology
Photocontrol

Electrical Information

Voltage
120V
Wattage Rating
1800.0W
Amps Rating
15.0 A

Item Details

SKU
K4121C
Brand
Intermatic
UPC
078275002012

Warranty & Certifications

Product Warranty
2 Years
Product Rating
Wet Rated

Frequently Asked Questions

What is the difference between Lumens and Watts?

Watts measure the amount of electrical energy a fixture consumes, while lumens measure the actual brightness (the amount of visible light produced). In the LED era, wattage is no longer a reliable indicator of brightness. When replacing old fixtures or comparing new ones, always look at the lumen output to determine how bright the light will be.

What is Color Rendering Index (CRI) and why does it matter?

CRI is a scale from 0 to 100 that measures how accurately a light source reveals the true colors of objects compared to natural sunlight. A higher CRI (90+) ensures colors look vibrant and accurate, which is critical for retail displays, kitchen countertops, and bathroom vanities. A lower CRI (under 80) can make colors look washed out or dull, regardless of the color temperature.

How do I know if my light fixture is dimmable?

For traditional incandescent fixtures, dimmability depended purely on the bulb. For modern LED lighting, dimmability depends on the internal LED driver or the specific LED bulb used. A fixture is only dimmable if its driver is explicitly rated for it. Furthermore, the fixture must be paired with a compatible dimmer switch (such as a standard TRIAC/Phase-cut dimmer or a 0-10V commercial dimmer) to prevent flickering and buzzing.

What does "Integrated LED" mean compared to a standard fixture?

An integrated LED fixture has the LED diodes and driver built directly into the housing, meaning there are no traditional bulbs to screw in or replace. This allows for sleeker, lower-profile designs and better heat dissipation. However, if an integrated fixture fails after its warranty period, you typically have to replace the entire unit or the internal driver, rather than just swapping out a bulb.

What does the "L70" lifespan rating mean on LED fixtures?

Unlike traditional bulbs that simply burn out and go dark, LEDs gradually lose their brightness over time (lumen depreciation). The L70 rating indicates the number of operating hours it takes for the LED fixture to degrade to 70% of its original brightness. For example, a fixture rated for "50,000 hours L70" will still work after 50,000 hours, but it will be noticeably dimmer than when it was first installed.

Digital Timer vs Mechanical Timer: Which One Should You Choose?

Intermatic

For over 130 years, Intermatic has been a leader in energy management, building a legacy on providing the most reliable time-based and light-responsive controls on the market. The brand is synonymous with durability, offering a comprehensive portfolio of "workhorse" products that professionals and homeowners have trusted for generations. From their iconic mechanical timers to their dependable photocells, Intermatic is the go-to choice for simple, powerful, and long-lasting control solutions.

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