Fermax Lock Release MOD.540Aa-S Max

Fermax 28151 Electric Lock Release MOD.540Aa-S Max (12Vac Automatic Fail Secure)

The Fermax 28151 is a robust electric lock release designed for standard timber or metal door frames, incorporating automatic re-locking and a manual override feature. Its designation indicates: 540 series standard body, Aa operation (Automatic Fail Secure AC with manual override), S type standard shield, and MAX adjustable latch. This model operates on 12V AC power.

Key operational details: The 540 denotes a standard size lock release body. Aa operation means it is Automatic-Fail Secure AC with Manual Override. It remains locked without power. A 12V AC pulse unlocks it, and it stays unlocked only until the door is opened and closed again, at which point it automatically re-locks mechanically. The a signifies the presence of a small manual override lever (or pestillo) on the strike body, which can be switched to hold the lock permanently unlocked for free passage until switched back. The S indicates it is fitted with a standard S-type flush shield (approx 25x160mm, grey). MAX confirms the adjustable jaw for easy alignment.

This combination of automatic re-locking, fail-secure operation, standard AC voltage compatibility, and manual override makes the 28151 a versatile choice for many residential and commercial applications using Fermax systems. The override lever is particularly useful for periods requiring free access without constantly buzzing the door open. Ensure AC power (12Vac) is available from the system transformer.

Features

• Standard Duty Electric Lock Release (540 Series Body)
• Operation: Aa - Automatic Fail Secure AC with Manual Override Lever
• Voltage: 12V AC
• 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 after door cycle
• Manual override lever for free passage mode
• Suitable for timber and standard metal frames

Technical Specifications

• Manufacturer: Fermax
• Model Reference: 28151 (Type 540Aa-S MAX)
• Operation Mode: Automatic Fail Secure AC with Manual Override
• Input Voltage: 12V AC
• Current Consumption (12V AC): Approx 980mA (verify datasheet)
• 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).