Electric Strike Siemens S24U (HARTTE) 24V AC/DC, standard series

The Siemens Electric Strike S24U (HARTTE) is a standard-series low-voltage door release unit designed for 24V AC/DC operation. Intended for integration with access control systems, intercoms and remote release panels, this electric strike enables secure remote unlocking of metal or wooden door frames while maintaining mechanical latching when idle. The compact design and standard fitting dimensions make it suitable for retrofit and new installations in residential and commercial entry systems where reliable, electrically controlled door release is required.

Advantages

The S24U electric strike supports both AC and DC 24V supply, offering flexible installation options with common low-voltage access control hardware. Its standard-series construction provides compatibility with typical door frames and allows straightforward mounting without extensive frame modification. Designed for continuous or impulse operation depending on system wiring, it offers consistent unlocking performance and maintains mechanical security when not energized.

Suitable for

• Access control systems in small offices and residential buildings
• Intercom and remote release installations
• Retrofit projects replacing mechanical strikes on metal or wooden frames
• Low-voltage door control where 24V AC or DC power is available

When it may not be suitable

This electric strike is intended for standard door frames and may not fit heavily reinforced, specialised or non-standard frame geometries without additional modifications. It is designed for 24V AC/DC systems; installations that require different supply voltages or integrated high-security features such as built-in monitoring sensors or motorised latches may require a different model.

Key specifications

• Operating voltage: 24V AC/DC
• Series: standard/flush-mount compatible design
• Function: remote electric door release for metal and wooden frames
• Operation mode: compatible with impulse and continuous wiring approaches
• Installation: suitable for retrofit and new installations with standard cutouts

How to use

Mount the electric strike in the door frame in place of or alongside an existing strike plate following the manufacturer’s mechanical dimensions and mounting instructions. Connect the 24V AC or DC supply according to the access control or intercom system wiring diagram, ensuring correct polarity for DC installations and appropriate protection such as fuses or breakers. Test the unlocking function from the control panel and verify that the mechanical latch engages correctly when the strike is not energized. Ensure power is isolated during wiring and that any local electrical codes are followed.

What to consider before purchase

• Confirm the door frame type and strike pocket dimensions match standard-series fittings
• Verify availability of 24V AC or DC power at the installation point
• Decide whether monitoring contacts or additional security features are required (this model is a standard electric strike)
• Check compatibility with your access control, intercom, or release device regarding wiring and operation mode

Usage recommendations

For reliable long-term operation, use a stable 24V supply, protect the circuit with appropriate fusing, and perform functional checks after installation. When replacing an existing strike, compare mechanical dimensions to minimise frame modification. For high-traffic doors consider periodic maintenance and inspection to ensure proper mechanical engagement and electrical connections.