Sangamo Astro Zone 1 Time Switch 20A 3 Pin 1 On/Off Day Omit

The Sangamo Astro Zone 1 is a programmable 24-hour time switch rated at 20A, designed to automate lighting and heating circuits based on a single daily on/off cycle. The unit fits standard 3-pin DIN rail enclosures and uses a rotating dial interface to set the switching times across a 24-hour period, with a day omit function that allows specific days to be skipped from the programmed operation.

Zone 1 time switches are used in commercial, industrial and residential electrical installations where lighting or heating loads need to follow a repeating daily schedule — typical applications include car park lighting, corridor lighting in apartment buildings, stairwell heating, external security lighting and shop front lighting. The 20A rating handles loads up to 4,600W on 230V circuits, suitable for controlling multiple luminaires or heating elements on a single channel.

The unit carries a 100-hour battery reserve, meaning the programmed schedule and current time are retained during mains power cuts of up to four days, avoiding the need to reprogram after brief outages. The clear rotating dial shows the full 24-hour cycle at a glance, with red markings indicating the on period and the central nut used to adjust the switching times. The day omit pins around the edge of the dial are removable to disable operation on selected days of the week.

The unit measures 104mm (height) × 83mm (width) × 134mm (depth) and weighs 422g, making it compact enough for installation in tight consumer unit enclosures while providing a robust mechanical build for long service life in switch rooms and plant areas.

Product Specification Sheet

Product Manual

How many on/off operations can be programmed per day?

The Astro Zone 1 supports one on/off operation per 24-hour cycle. The dial shows the full day, and the red section marks the on period — everything outside that section is off.

What does the day omit function do?

The day omit pins around the edge of the dial can be removed to disable operation on specific days of the week. This allows the switch to skip weekends or bank holidays without reprogramming the main cycle.

Does it need to be reprogrammed after a power cut?

No, if the power cut lasts less than 100 hours. The unit has a battery reserve that maintains the programmed schedule and keeps the internal clock running during brief outages.

What is the maximum load it can switch?

The 20A rating allows the switch to control loads up to 4,600W on 230V circuits. For resistive loads like incandescent lamps or heating elements this is the continuous rating; for inductive loads (fluorescent ballasts, motors) consult the datasheet for derating factors.