Sangamo Round Pattern Astro Zone 3 Time Switch - 4 Pin 20A

The Sangamo Q553 is a round pattern astro zone 3 time switch with a 4-pin control interface, 20A resistive switching capacity and 24-hour programmable scheduling. The astro function adjusts switching times automatically to sunrise and sunset throughout the year, eliminating the need to reprogram the unit seasonally for outdoor lighting, security lighting or heating control.

Designed for commercial and industrial applications where lighting or heating circuits need to follow daylight hours, the Q553 suits exterior building lighting, car park lighting, street lighting and security perimeter lighting. The zone 3 astro calculation uses a UK-wide average sunrise/sunset table, which provides acceptable accuracy for most fixed outdoor lighting installations without requiring GPS or location-specific programming. The 4-pin interface allows manual override and mode selection without removing the unit from its enclosure.

The round pattern housing measures 104mm diameter and 134mm deep, fitting standard DIN-rail or panel-mount enclosures. The 20A resistive rating handles up to 4,600W on 230V mains, suitable for controlling multiple luminaires on a single circuit. A 100-hour battery reserve maintains the programmed schedule and clock during mains outages, preventing the need to reprogram after brief power cuts. The mechanical dial and pointer give visual confirmation of the current time position and next scheduled switching event.

Product Specification Sheet

Product Manual

What does zone 3 astro mean?

Zone 3 refers to the UK-wide average sunrise and sunset times used by the astro calculation. The switch automatically adjusts on and off times to follow seasonal daylight changes without manual reprogramming. Zone 3 is suitable for most UK locations where exact sunrise/sunset precision is not critical.

What is the 20A rating suitable for?

The 20A resistive rating handles loads up to 4,600W on 230V mains. This is sufficient for controlling multiple LED or discharge luminaires on a single outdoor lighting circuit, or for switching heating circuits in commercial buildings.

How long does the battery reserve last?

The 100-hour battery reserve maintains the programmed schedule and internal clock during mains outages. This prevents the need to reprogram the unit after brief power cuts or maintenance shutdowns.

Can the switching times be overridden manually?

Yes. The 4-pin control interface allows manual override to force the output on or off regardless of the programmed astro schedule. See the product manual for the specific override procedure for this model.