Fermax Lock Release MOD.540Aa-412-S Max

Fermax 28171 Electric Lock Release MOD.540Aa-412-S Max (12Vdc Automatic Fail Secure)

The Fermax 28171 is a versatile electric lock release designed for standard door frames, featuring automatic re-locking, fail-secure operation, manual override, and compatibility with 12V DC power sources. Its type code breakdown is: 540 series standard body, Aa operation (indicating Automatic and Manual Override), 412 voltage (12V DC), S type standard shield, and MAX adjustable latch.

Operationally, the 540 body is a standard size suitable for most timber and metal frames. The Aa signifies it is an Automatic Fail Secure lock with a Manual Override Lever. It remains locked without power. A 12V DC (412) pulse unlocks it temporarily. It will automatically re-lock mechanically only after the door has been physically opened and then closed again. The manual override lever (a) allows the lock to be set to a permanently unlocked state for periods of free access, until the lever is reset. The S shield is the standard flush fitting plate (approx 25x160mm, grey), and MAX indicates the adjustable jaw for precise alignment.

This combination makes the 28171 suitable for applications requiring the security of automatic re-locking after use and fail-secure operation (locked on power failure), while also needing the convenience of a manual override for specific situations (e.g., deliveries, events). Its 12V DC operation makes it compatible with many standard access control systems and specific Fermax DC-powered intercom setups.

Features

• Standard Duty Electric Lock Release (540 Series Body)
• Operation: Aa - Automatic Fail Secure DC with Manual Override Lever
• Voltage: 412 - 12V DC
• Shield: S Type Standard Flush Shield (approx 25mm x 160mm) - Grey
• Latch: MAX Adjustable Jaw (+/- 4mm adjustment)
• Reversible design (Left/Right DIN)
• Symmetrical body
• Automatic re-locking function after door use
• Manual override lever (pestillo) for free passage option
• Suitable for standard timber and metal door frames

Technical Specifications

• Manufacturer: Fermax
• Model Reference: 28171 (Type 540Aa-412-S MAX)
• Operation Mode: Automatic Fail Secure DC with Manual Override
• Input Voltage: 12V DC
• Current Consumption (12V DC): Check datasheet (pulse current likely)
• Body Series: 540 (Standard)
• Shield Type: S Type Flush Plate (Grey, approx 25x160mm)
• Latch: MAX Adjustable
• Holding Force: Refer to Fermax datasheet

Dimensions

• Body Dimensions (540 approx): 75mm x 21mm (height x width) - depth varies.
• S Shield Dimensions (approx): 160mm x 25mm (height x width).