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Gray polycarbonate photocontrol timer with half-inch threaded mount

Intermatic

Intermatic K4221C 1800 W Photocontrol Timer Switch

SKU CH-5TJT-ZVHHE

Photocontrol timer switch with dusk-to-dawn operation, 1800 W capacity and raintight polycarbonate housing

  • Automatic dusk-to-dawn lighting control with built-in photocontrol sensor
  • Handles up to 1800 W for fluorescent, HID and incandescent loads
  • Operates reliably from -40 °F to 158 °F in raintight polycarbonate housing
  • Mounts directly to 1/2 in conduit with included lock nut and gasket
  • cCSAus and UL listed, meets California Title 20 standards

1800 W Photocontrol Timer Switch

The Intermatic K4221C is a dusk-to-dawn photocontrol timer switch rated for 1800 W at 120 V AC. It controls fluorescent, HID and incandescent lighting loads automatically based on ambient light levels. The unit mounts via a 1/2 in male pipe thread and includes a lock nut and washer gasket for a raintight seal. It is suited for outdoor lighting circuits that require reliable automatic operation.

Raintight enclosure rated -40 °F to 158 °F

The polycarbonate housing carries a raintight enclosure rating and operates across a temperature range of -40 degrees to 158 degrees Fahrenheit. The SPST contact form handles up to 15 A for incandescent loads and 8.3 A for ballast loads. Power draw in normal use is limited to the connected lighting load, with no active cooling or moving parts to generate noise. The photocell activates between 1.0 and 5.0 foot-candles on and 3 to 15 foot-candles off.

Includes lock nut and washer gasket

The bundled lock nut and washer gasket provide the hardware needed to secure the 1/2 in male pipe thread mounting and maintain the raintight enclosure rating. No additional software, programming tools or remote accessories are included or required for the dusk-to-dawn setting. Buyers who need adjustable timing schedules, multi-channel control or smart-home integration should select a programmable timer instead.

Highlights

  • Automatic dusk-to-dawn lighting control with built-in photocontrol sensor
  • Handles up to 1800 W for fluorescent, HID and incandescent loads
  • Operates reliably from -40 °F to 158 °F in raintight polycarbonate housing
  • Mounts directly to 1/2 in conduit with included lock nut and gasket
  • cCSAus and UL listed, meets California Title 20 standards

Specifications

BrandINTERMATIC

Questions about this item

How do I mount the K4221C photocontrol timer switch using its 1/2 in male pipe thread, and what step is often missed?

Thread the unit into a 1/2 in female fitting, then secure the included lock nut and washer gasket; the gasket is the step most installers forget, and without it the raintight seal fails.

What component will need replacement first on the K4221C, and how can I tell?

The SPST relay contacts wear from switching up to 15 A incandescent or 8.3 A ballast loads; when lights flicker at dusk or fail to turn off at dawn, the contacts are pitted and the unit must be replaced.

At what ambient temperature does the K4221C reach its operating limit during continuous use?

The rated range tops out at 158 Degrees F; sustained operation above that temperature will cause the polycarbonate housing to soften and the internal electronics to drift out of calibration.

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