Bistable relay 12VAC 2NO 16A EPN521

Bistable relay with manual operation and DIN rail mounting

The device operates as a pulse‑switching mechanism – a short control signal is sufficient to change its state. It does not require continuous voltage to hold the position, reducing power consumption to a minimum. In the “on” or “off” state it remains without any power, and the state changes after the next pulse from a button or controller.

It has two normally open contacts (2NO) that can handle loads up to 16 A at 250 V AC. It is ideal for controlling lighting, ventilation or other devices in residential and commercial installations where central control from multiple points is required.

For installer – ease of installation and flexibility

It mounts on a DIN rail, occupies exactly 1 module (17.5 mm width) and has a mounting depth of 63 mm – fitting standard distribution boards. Screw terminals accept rigid conductors from 1.5 to 10 mm² and flexible ones from 1 to 6 mm², providing cable selection flexibility. The manual switching option allows quick diagnostics or emergency operation without needing access to the control system.

The control voltage is only 12 V AC – safe and easy to integrate with home systems, motion sensors or building automation. The frequency 50–60 Hz matches the standard European power grid.

For user – reliability and control

You don’t have to hold the button – one press turns on, another turns off. This means there is no risk of a “stuck” signal or accidental shutdown due to a controller error. Example: in a corridor with three switches – each can change the lighting state without affecting the others.

The lamp load capacity reaches up to 1800 W for incandescent bulbs and up to 800 VA for fluorescent lamps (or even 1600 VA with Duo compensation). This is sufficient for most modern lighting systems, including ballast‑equipped LEDs.

Operating temperature range from -5 °C to +40 °C ensures stability in residential and office environments. Storage from -40 °C to +80 °C does not affect parameters – the device withstands transport and storage.

All of this complies with DIN EN 60669-1 and DIN EN 60669-2-2 – meaning it is designed and tested as an installation device intended for frequent use.