Sangamo Round Pattern Astro Zone 2 Time Switch - 4 Pin 20A

The Sangamo Q553 is a round pattern astro zone 2 time switch with 4-pin mechanical programming, 20A switching capacity and a 100-hour battery reserve. The unit controls lighting circuits based on a 24-hour schedule with on/off operations set using four brass pins positioned around the dial, which rotates once per day to trigger switching at the programmed times.

Designed for exterior lighting, car park lighting, street lighting and commercial building perimeter lighting in UK Zone 2 (approximately 51-55° latitude), the astro function automatically adjusts switching times throughout the year to track sunrise and sunset without manual reprogramming. The 20A rating handles lighting loads up to 4,600W on 230V mains, making it suitable for controlling multiple luminaires on a single circuit. The 100-hour battery reserve maintains timekeeping during mains interruptions, eliminating the need to reset the clock after brief power cuts.

The round dial face shows a 24-hour scale with red markings for easy pin positioning in low-light conditions. The four brass pins clip into slots around the dial perimeter, with each pin triggering one on or off event per 24-hour cycle. The clear plastic front cover protects the dial mechanism while allowing visual confirmation of the current time position. The unit mounts onto a standard 35mm DIN rail inside a distribution board or dedicated time switch enclosure, and wiring terminates onto screw terminals on the rear of the case.

Product Specification Sheet

Product Manual

What does Zone 2 mean?

Zone 2 refers to the UK latitude band approximately 51-55° north, covering most of England including London, Birmingham, Manchester and Leeds. The astro function in this time switch is calibrated to track sunrise and sunset times for this latitude range throughout the year.

How is the switching time programmed?

Four brass pins clip into slots around the dial perimeter. Each pin triggers one on or off event per 24-hour cycle. The dial rotates once per day, so when a pin reaches the top of the dial it closes or opens the switching contact depending on which terminal the circuit is connected to.

What mounting is required?

The time switch mounts onto a standard 35mm DIN rail inside a distribution board or dedicated enclosure. It does not include an enclosure and must be installed in a suitable IP-rated housing if used outdoors or in damp locations.

How long does the battery reserve last?

The 100-hour battery reserve maintains timekeeping during mains interruptions. This covers most short power cuts without requiring the clock to be reset. The battery is internal and replaceable once it reaches end of life.