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

The Sangamo Round Pattern Astro Zone 4 is a programmable time switch designed to control lighting circuits based on sunset and sunrise times specific to Zone 4 regions of the UK. The unit features a 4-pin configuration, 24-hour programming with on/off operations, and a 20A current rating suitable for controlling street lighting, security lighting and commercial exterior lighting installations.

The astro function automatically adjusts switching times throughout the year to match the changing daylight hours in Zone 4 areas, removing the need for manual seasonal reprogramming. The time switch mounts in standard electrical enclosures and connects via the 4-pin interface to lighting contactors or direct loads up to 20A at 230V. The 100-hour battery reserve maintains programming and timekeeping during mains power interruptions.

The round dial face displays a 24-hour clock with red graduations marking hourly and 15-minute intervals, allowing visual confirmation of current time and programmed switching positions. Brass terminals provide secure connection points, and the transparent cover allows inspection of the dial position without opening the enclosure. The unit measures 104mm diameter by 134mm depth and weighs 423g, fitting standard back boxes used in street furniture and commercial lighting control panels.

Product Specification Sheet

Product Manual

What is Zone 4 and does it cover my area?

Zone 4 covers specific UK regions with particular sunset and sunrise timing patterns. The Sangamo manual linked in the Downloads section includes a map showing which postcodes fall within Zone 4. If your installation is in a different zone, you will need the corresponding zone model to ensure accurate astro timing.

What is the 4-pin configuration used for?

The 4-pin interface connects the time switch to external lighting contactors or control circuits. This allows the low-current switching mechanism inside the time switch to control high-load lighting circuits indirectly, rather than switching the full load current directly through the unit.

How long does the battery reserve last?

The 100-hour battery reserve maintains programming and timekeeping during mains power cuts for approximately four days. After this period, if mains power has not been restored, the unit will require reprogramming once power returns.

Can the astro function be overridden?

Most Sangamo astro time switches allow manual override or adjustment of the programmed switching times. Refer to the product manual in the Downloads section for specific override procedures and programming instructions for this model.