ESP Aperta Fail Secure Surface Strike Lock | A1SLS

12V DC Surface-Mounted Electric Strike with 400kg Maximum Holding Force

The ESP Aperta A1SLS Fail Secure Surface Strike Lock is a robust 12V DC electric door release designed for use with Yale-type surface locks as part of compatible door entry and access control installations.

Featuring fail-secure operation, the A1SLS remains locked when power is removed, helping maintain door security during a loss of electrical supply. When the appropriate 12V DC supply is applied, the strike releases to permit authorised access.

Manufactured from durable aluminium alloy with a brushed silver finish, the A1SLS provides a maximum holding force of 400kg and is designed specifically for surface mounting. Its non-polarised power connections help simplify wiring, while the compact 110 × 50 × 32mm construction provides a practical solution for compatible residential and commercial access-controlled doors.

Part of the ESP Aperta access control range, the A1SLS can be incorporated into suitable door entry, keypad and access control systems where an electrically operated fail-secure surface strike is required.

Features

• ESP Aperta Fail Secure Strike Lock
• Product Code A1SLS
• Surface-Mounted Design
• 12V DC Operating Voltage
• Fail Secure Operation
• Maximum 400kg Holding Force
• Designed for Yale-Type Surface Locks
• Aluminium Alloy Construction
• Brushed Silver Finish
• Non-Polarised Power Connections
• 250mA Power Consumption
• Compact 110 x 50 x 32mm Dimensions
• Operating Temperature -20°C to +50°C
• Fixing Screws Supplied
• Suitable for Access Control Systems
• Suitable for Door Entry Systems
• Flush-Mounted A1SL Version Also Available
• 3-Year Guarantee

Fail Secure Door Operation

The A1SLS operates on a fail-secure principle.

This means the door strike remains mechanically secure when electrical power is removed. Power is applied to release the strike and allow the door to be opened by an authorised user.

Fail-secure operation is particularly useful for suitable access-controlled doors where maintaining security during a power interruption is a priority.

The correct locking arrangement must always be selected according to the door's purpose, access-control design, fire strategy and emergency escape requirements.

Designed for Yale-Type Surface Locks

ESP specifically designs the A1SLS for use with Yale-type surface locks.

This makes it particularly suitable for installations where a compatible surface or rim-style locking arrangement needs to be integrated with an electronic access control or door entry system.

Compatibility with the exact lock, door and frame arrangement should always be confirmed before installation.

Surface-Mounted Installation

Unlike the ESP A1SL flush strike, the A1SLS is designed specifically for surface mounting.

This can make it a practical choice where recessing a strike into the door frame is undesirable or where the existing door arrangement uses a compatible surface lock.

The surface-mounted configuration is also useful for appropriate retrofit installations where minimising modifications to the existing door frame can simplify installation.

400kg Maximum Holding Force

The A1SLS provides a maximum holding force of 400kg

This makes it suitable for a variety of appropriate residential and commercial security applications.

The stated holding force relates to the strike itself and should not be interpreted as a security rating for the complete door installation. Overall security depends on the door, frame, lock, fixings and complete access-control arrangement.

12V DC Operation

The strike operates from a 12V DC supply, making it suitable for integration with compatible access control power supplies and door entry equipment.

Power consumption is specified at 250mA.

The associated power supply should therefore be appropriately rated for the strike and any other equipment connected to the same supply.

Non-Polarised Power Connections

The A1SLS features non-polarised power connections.

This means there is no positive or negative polarity requirement at the strike's power input, helping simplify the electrical connection during installation.

Correct voltage and system wiring requirements must still be observed.

Aluminium Alloy Construction

The strike is manufactured from aluminium alloy, providing a robust construction suitable for regular operation within compatible access control installations.

Its brushed silver finish provides a professional appearance that coordinates well with many commercial and residential door hardware installations.

Compact Surface Strike

With dimensions of approximately 110mm x 50mm x 32mm

The installation position and available clearance should be checked against these dimensions before fitting.

Wide Operating Temperature Range

The A1SLS is specified for operation between -20°C and +50°C.

The suitability of the complete installation for a particular environment should nevertheless be assessed before installation, including the location, door construction and exposure to moisture or weather.

No external IP rating should be assumed for the A1SLS unless specifically stated for the installation.

Suitable for Access Control Systems

The ESP Aperta A1SLS can be incorporated into suitable access control installations where an electrically released door is required.

Depending on the complete system design, the strike can be controlled by compatible equipment such as:

• Keypad Access Systems
• Proximity Access Systems
• Video Door Entry Systems
• Audio Door Entry Systems
• Access Control Relays
• Exit Devices
• Suitable Door Release Controls

All associated equipment must provide the appropriate switching and power arrangements required by the strike.

Integration with ESP Aperta Systems

As part of ESP's Aperta access control range, the A1SLS can be used as the locking component within suitable ESP door entry and access control installations.

ESP's own documentation provides wiring examples using compatible equipment such as the EVBPSBB boxed power supply and A1ECP emergency door release call point.

These components are separate products and are not included with the A1SLS unless specifically supplied as part of a kit.

A1SLS vs A1SL

ESP offers both surface and flush versions of its fail-secure strike lock.

A1SLS – Surface Strike Lock
Designed for surface mounting and Yale-type surface locks.

A1SL – Flush Strike Lock
Designed for flush mounting and Yale-type rim locks.

The correct model should be selected according to the physical door and locking arrangement.

• Brand: ESP
• Range: Aperta
• Product Code: A1SLS
• Product Type: Electric Strike Lock
• Lock Type: Fail Secure
• Mounting: Surface
• Operating Voltage: 12V DC
• Power Consumption: 250mA
• Maximum Holding Force: 400kg
• Lock Compatibility: Yale-Type Surface Locks
• Power Connection: Non-Polarised
• Material: Aluminium Alloy
• Finish: Brushed Silver
• Dimensions: 110 x 50 x 32mm
• Operating Temperature: -20°C to +50°C
• Fixing Screws Supplied: Yes
• Guarantee: 3 Years

What Does Fail Secure Mean?

A fail-secure electric strike remains locked when electrical power is unavailable.

During normal controlled operation, the access control system supplies power to release the strike when authorised entry is requested.

This differs from a fail-safe locking device, which releases when power is removed.

The distinction is important when designing an access control system, particularly where emergency escape or fire safety requirements apply. The locking method must always be appropriate for the specific door and building requirements.

Suitable Applications

• Door Access Control Systems
• ESP Aperta Access Control
• Yale-Type Surface Lock Installations
• Residential Access Control
• Commercial Access Control
• Office Doors
• Apartment Buildings
• Communal Entrances
• Door Entry Systems
• Video Door Entry Systems
• Audio Door Entry Systems
• Keypad Entry Systems
• Proximity Access Systems
• Controlled Entrance Doors
• Retrofit Access Control
• Professional Security Installations

Installation Considerations

Before installing the A1SLS, confirm that the existing lock and door arrangement are mechanically compatible with a Yale-type surface strike.

The installer should also ensure that the access-control system provides the correct 12V DC electrical supply and appropriate switching arrangement.

Because the unit is fail secure, consideration must also be given to emergency egress, fire safety and any applicable access-control requirements for the particular door.

Why Choose the ESP Aperta A1SLS?

The ESP Aperta A1SLS provides a straightforward way to introduce electronic access control to a compatible door fitted with a Yale-type surface locking arrangement.

Its surface-mounted construction makes it particularly useful where a flush strike is unsuitable, while the 400kg maximum holding force

A 12V DC operating supply, non-polarised connections and fixing screws supplied help simplify installation, while the aluminium-alloy construction and brushed silver finish provide a durable, professional appearance.

Most importantly, its fail-secure operation keeps the strike locked when power is removed, making it suitable for access-controlled applications where maintaining security during a power interruption is required.

For installers working with ESP Aperta door entry and access control equipment, the A1SLS offers a compact, purpose-designed surface strike solution backed by a 3-year guarantee.