Weekly digital timer 1-channel D21 412631

Precise time control for electrical installations

The D21 weekly digital timer is an advanced control device designed for the automatic switching on and off of electrical circuits in residential, commercial, and industrial installations. Its single-channel design with precise quartz control allows for the programming of up to 56 different programs with an accuracy of one second.

Functionality and programming capabilities

The device offers comprehensive programming functions that cover most home and industrial automation needs. Daily and weekly programming allows for flexible management of lighting, heating, or other electrical loads according to a set schedule. Automatic daylight saving time adjustment eliminates the need for manual setting corrections during time changes.

A particularly practical feature is the holiday program, which enables the programming of special schedules for vacation or holiday periods. The random program simulates occupancy by randomly shifting programmed switching cycles within a range of ±15 minutes - an ideal solution for home security systems.

For more advanced applications, a cyclic program is available, allowing for the creation of repetitive on/off sequences at specific time intervals. The device also supports manual operation, enabling immediate user intervention without the need to modify programmed settings.

Technical parameters and construction

The timer is characterized by precise quartz control with an accuracy of ±0.1 seconds per day, guaranteeing reliable operation over long periods without the need for calibration. A 5-year power reserve ensures continuity of operation even during mains power interruptions.

The modular design with a width of 2 modules (35.6 mm) allows for mounting on a standard TH35 DIN rail in electrical distribution boards. The IP20 protection rating protects against finger contact and against access to solid objects larger than 12 mm.

The output is provided via a volt-free changeover contact (NO/NC) with a load capacity of 16A at 250V AC, allowing for direct control of most typical household loads - from LED lighting to heating stoves with a power of up to 4000W at cos φ = 1.

Regulatory compliance and operating conditions

The device meets the requirements of international standards IEC/EN 60730-1 and IEC/EN 60730-2-7 as well as VDE 0631 part 1 and part 2-7, confirming its high standards of safety and reliability. The "S" type construction (controller) according to IEC classification guarantees stable operation in typical environmental conditions.

An operating temperature range from -20°C to +55°C and a storage temperature from -20°C to +60°C allow for installation in various locations - from unheated utility rooms to outdoor distribution boards. An AC power supply of 230V ±10% at a frequency of 50/60 Hz ensures compatibility with Polish power grids.

An additional advantage is the possibility of external programming via dedicated Legrand AlphaSoft software and data transfer keys, which significantly simplifies the configuration of many identical devices in large installations.