Intermatic K4421M 120VAC 1800W Stem Photocontrol Instruction Manual

1. Product Overview

The Intermatic K4421M is a stem-mounted, thermal-type photocontrol designed for dusk-to-dawn lighting applications. This unit provides automatic control of lighting based on ambient light levels. Its thermal-type mechanism includes a delay action to prevent nuisance switching caused by transient light sources like vehicle headlights or lightning. The K4421M features a robust cadmium sulfide photocell and a sonic-welded polycarbonate case and lens for moisture protection. The design incorporates a dual temperature compensating bimetal and composite resistor to ensure reliable operation across various ambient temperature conditions. This model is California Title 24 compliant and features a heavy-duty die-cast housing for enhanced durability.

Figure 1: Intermatic K4421M Stem Photocontrol. A close-up view of the Intermatic K4421M stem photocontrol, featuring its metal housing, light sensor, and wiring leads extending from the bottom.

2. Safety Information

WARNING: Risk of electric shock. Installation should be performed by a qualified electrician in accordance with all national and local electrical codes.

• Disconnect power at the circuit breaker or fuse box before installing or servicing the photocontrol.
• Ensure all wiring connections are secure and properly insulated.
• Do not exceed the specified voltage and wattage ratings of the photocontrol.
• This device is intended for outdoor use and must be installed in a location protected from direct water spray.

3. Package Contents

• Intermatic K4421M Stem Photocontrol
• Washer Gasket
• Locking Nut
• Instruction Sheet (this document)

4. Specifications

5. Installation Instructions

Before You Begin: Ensure power is disconnected at the main circuit breaker. Read all safety information.

1. Mounting Location: Select a mounting location where the photocontrol sensor will receive natural ambient light and will not be affected by artificial light sources (e.g., streetlights, floodlights) or reflections, which could cause erratic operation. The sensor should face generally North for optimal performance.
2. Prepare Mounting Hole: The photocontrol is designed for stem mounting through a 1/2-inch conduit knockout or similar opening.
3. Secure the Photocontrol:
   • Insert the threaded stem of the photocontrol through the mounting hole.
   • Place the provided washer gasket over the stem on the outside of the fixture or enclosure to create a weather-tight seal.
   • Thread the locking nut onto the stem from the inside of the fixture or enclosure and tighten securely to hold the photocontrol in place.
4. Wiring Connections: The K4421M photocontrol has 6-inch color-coded leads. Connect them as follows:
   • Black Wire: Connect to 120 VAC Line (Hot) input.
   • White Wire: Connect to Neutral.
   • Red Wire: Connect to Load (lighting fixture).
   Ensure all connections are made with appropriate wire connectors and are insulated.
5. Light Level Adjustment (if applicable): This model features a light level slide adjustment. If present, adjust the slide to set the desired turn-on light level. Moving the slide towards the "darker" setting will cause the unit to turn on at lower light levels, and towards "lighter" will cause it to turn on at higher light levels.
6. Restore Power: Once all connections are secure and the photocontrol is properly mounted, restore power at the circuit breaker.

6. Operation

The Intermatic K4421M photocontrol operates automatically, turning connected lighting ON at dusk and OFF at dawn. The thermal-type design incorporates a built-in time delay (typically 10-20 seconds) to prevent false switching due to momentary light changes, such as car headlights or lightning flashes. After installation and power restoration, the unit will cycle once to calibrate to ambient light conditions. Allow one full day/night cycle for the photocontrol to establish its normal operating pattern.

7. Maintenance

The K4421M photocontrol is designed for maintenance-free operation. Periodically inspect the sensor lens for any accumulation of dirt, dust, or debris. Clean the lens gently with a soft, damp cloth if necessary to ensure accurate light sensing. Do not use abrasive cleaners or solvents. Ensure the photocontrol remains securely mounted and that wiring connections are intact.

8. Troubleshooting

9. Warranty and Support

For warranty information, technical support, or further assistance, please contact Intermatic customer service. Refer to the official Intermatic website or product packaging for the most current contact details and warranty terms.

Manufacturer: Intermatic Incorporated

Website: www.intermatic.com