Sangamo Q555 24 Hour 4 Pin 3 On/Off Time Switch - Round Pattern 20A

The Sangamo Q555 is a 24-hour programmable time switch with a 4-pin round pattern dial that controls up to three on/off cycles per day at a 20A rating. The mechanical timer uses removable pins set around the dial face to trigger switching points as the dial rotates through its 24-hour cycle, with a day omit function that skips programmed cycles on selected days.

Designed for controlling immersion heaters, central heating systems, commercial lighting circuits and industrial equipment that requires daily scheduled operation, the Q555 fits standard electrical enclosures and consumer units. The manual override button allows temporary switching outside the programmed schedule without disturbing the pin positions, returning to automatic operation once released. The 100-hour battery reserve maintains the timer's accuracy during mains power interruptions without needing reprogramming.

The round dial face shows a red and white 24-hour scale with clearly marked hour divisions, with pins inserted at the desired on and off times. The transparent cover protects the dial and pins from dust and accidental adjustment while remaining visible for quick schedule checks. The 20A switching capacity handles resistive loads up to 4,600W on 230V circuits, with lower ratings applying to inductive loads such as motor starters.

Product Specification Sheet

Product Manual

How are the on/off times set?

The Q555 uses removable pins inserted around the dial at the desired switching times. Push a pin in at the time you want the switch to turn on, and insert another pin at the time you want it to turn off. The dial rotates once every 24 hours, triggering the switches as each pin passes the contact point.

What does the day omit function do?

The day omit dial allows the timer to skip its programmed cycles on selected days without removing the pins. This is useful for skipping weekend heating schedules or bank holidays without reprogramming the entire timer.

Does it need batteries?

The Q555 runs on mains power but includes a 100-hour battery reserve that keeps the timer running during power cuts. The battery maintains timekeeping accuracy so the schedule does not drift when power is restored.

What load can it switch?

The timer is rated at 20A on 230V circuits, handling resistive loads such as immersion heaters and lighting up to 4,600W. Inductive loads like motors and fluorescent ballasts require derating — check the specification sheet for exact inductive ratings.