Intermatic K4221C Control

Professional-grade Intermatic K4221C Control units are the industry standard for reliable dusk-to-dawn lighting control. Built for the rigors of the field, this thermal photocontrol features a robust mechanical bimetal switch and a precision cadmium sulfide photocell to ensure consistent performance across extreme temperature ranges from -40?F to 158?F. The stem and swivel mount design, featuring a 1/2"-14 NPSM threaded stem, allows for flexible directional aiming, making it ideal for parking lot lighting, floodlights, and exterior security fixtures.

This 120V unit supports heavy-duty loads up to 15A tungsten and 1000VA ballast. To improve system reliability, the Intermatic K4221C incorporates a built-in 30-to-90-second time delay feature. This critical function prevents "nuisance switching" or flickering caused by transient light sources such as car headlights or lightning. The sonic-welded polycarbonate housing and included washer gasket provide a rain-tight seal, protecting the internal components from moisture and UV degradation in demanding outdoor environments.

Key Benefits for Contractors:

• Versatile Positioning: The swivel arm allows for precise orientation of the light sensor to avoid interference from artificial light sources.
• High Load Capacity: Rated for 1800W Tungsten and 8.3A Magnetic Ballast, suitable for most commercial HID and incandescent fixtures.
• Fail-Safe Operation: Designed to fail in the "ON" position, ensuring safety and visibility even if the photocell is compromised.
• Rapid Installation: Includes 6-inch color-coded 18 AWG leads and a locking nut for fast integration into standard conduit bodies or weatherproof boxes.

Common Questions:

How do I prevent the light from cycling on and off at night?
Ensure the photo eye is not facing toward the light fixture it controls or any reflective surfaces. Using the swivel mount, aim the sensor toward the north sky for the most stable natural light readings.

Is the Intermatic K4221C compatible with LED fixtures?
While primarily engineered for thermal loads like HID and incandescent, it can control LEDs within its 120V rating. However, for high-inrush LED drivers, an electronic photocell may provide a longer service life.

What is the purpose of the 30-90 second delay?
The delay prevents the contactor from dropping out immediately when hit by a temporary flash, such as passing traffic, ensuring the lamp strikes remain consistent and protected from unnecessary wear.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.