Mechanical timer switch ORNO OR-PRE-443 — ORNO mechanical time programmer, analogue daily schedule

Mechanical timer switch ORNO OR-PRE-443 is an analogue daily time programmer designed to switch electrical circuits according to a daily schedule. The device provides manual and automatic modes and allows setting multiple on/off segments within a 24-hour period. It is intended for basic time-based automation of lighting, heating controls, pumps and other household or light commercial appliances where simple, reliable daily scheduling is required.

Advantages

The mechanical construction ensures straightforward operation and does not rely on complex software or network connectivity. The analogue dial with selectable segments allows easy setting of multiple switching intervals over a 24-hour cycle. Manual override lets the user temporarily bypass the programmed schedule without losing the stored settings. The robust design is suitable for wall- or DIN-rail mounting in utility panels and for use in environments where simple, repeatable daily control is needed.

Suitable for

• Scheduled control of indoor and outdoor lighting
• Time-based switching of heating elements and boiler circulation pumps
• Automatic operation of water pumps, ventilation fans and small motors
• Simple daily automation in residential apartments, garages and small commercial premises

Key specifications

• Analogue 24-hour dial with selectable on/off segments for daily programming
• Manual/automatic mode selection with temporary override
• Designed for mounting in electrical panels or on DIN rail (form factor compatible with utility installations)
• Compatible with mains AC loads for switching lighting, heating and small motors
• Durable mechanical switching mechanism for repeatable daily operation

How to use

Set the current time on the 24-hour analogue dial, then push or move the segments corresponding to the desired on and off periods to create a daily schedule. Use the manual override to switch the output on or off temporarily without altering the programmed segments. Install the timer in accordance with local electrical regulations, ensuring correct wiring to the mains supply and the controlled load. Periodically check the mechanical contacts and the integrity of the timer housing, especially in environments with dust or moisture.

Usage recommendations

For reliable operation, use the timer to control loads within its rated current and voltage limits and avoid inductive loads that exceed the device specification. Install the unit in a dry, ventilated enclosure away from direct exposure to water. If switching motors or pumps, consider adding appropriate surge suppression or contactor interposing relays for higher currents or inductive characteristics.