Westire Zhaga photocell

DALI D4i dimming & part-night photocell

Advanced dimming and part-night function for cost and energy savings


Westires Zhaga DALI D4i dimming and part-night  photocell utilises Westire Eye Response filtered silicon based ambient light sensor and microprocessor control running advanced algorithms. This combination provides the best energy savings and reliable operation.


Engineered and assembled in the EU, with a 20 year design life using only name brand components and high quality materials. The Zhaga 9000 series photocells are of renowned quality all while maintaining value and reliability. Each unit has a full electrical and 48 hour operational burn-in test before leaving the factory.

Designed to meet the needs of DALI enabled LED smart street light luminaries.

Features & Benefits

  • Cost savings through reduced power consumption
  • Same accurate ambient light sensing as all Westire photocells

  • Part-night, On/Off & dimming schedules programmed to your specification

  • World’s most advanced A.I. solar time clock algorithms

  • DALI D4i communications to the LED driver

  • Low voltage 24Volts DC

  • No photocell switching circuitry.

  • Complies with the Zhaga Book 18 Interface.
  • DALI2 – D4i compliant
  • Fits into the Zhaga socket without the need to disconnect the mains supply
  • Self-correcting dimming and part-night function
  • Engineered, assembled & tested in our Irish manufacturing facility
  • World’s top brand electronic components and materials used



  • Automatically switches street lights off/on at dawn/dusk.

  • Road, street lighting and area lighting controls.

  • Custom calculated midnight dimming.

  • Interfaces with DALI-2 enabled LED luminaire drivers.

  • Ideal for all types of DALI enabled outdoor lighting controls.

  • Wall mounting bracket available.

Technical Specifications

Dimensions40mm D x 30mm H
1.5" x 1.8"
Photocell TypeZhaga Book 18 D2 & D4i
Zhaga Book 18
Luminaire FixingZhaga Book 18
Standard Socket
Warranty8 years standard
Driver Supply voltage24 Volts DC
Average Power Consumption<0.01 Watts
Operating Temperature-30⁰C to +70⁰C
-22⁰F to +158⁰F
Enclosure Protection RatingHigh impact IK09 impact rated protection. IP66.
Standards ComplianceDALI-2, D4I,
IS EN ISO 9001: 2015,
Environmental RoHS.
Switch “On” Light Level20:20 Lux
Other switching available on request.
Switching Ratio1:1 Standard.
Other settings available on request.
Ambient Light SensorColour corrected silicon sensor
Switching Time DelayInstant “On” :25 Seconds Delay Off or as specified.
Switching/Dimming OptionsDALI dusk to dawn.
Multiple dimming options available.