Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of the Tesa Assa Abloy Lock with Metallic Profiles, Model 4240303NI. Please read this manual thoroughly before installation and use to ensure proper function and safety. This lock is designed to facilitate installation in European profiles with camera, featuring a box of less than 15 mm to avoid machining of nerves.
Safety Information
- Always wear appropriate personal protective equipment (PPE) during installation, such as safety glasses and gloves.
- Ensure all components are present and undamaged before beginning installation.
- Do not modify the lock or its components. Unauthorized modifications can compromise security and void the warranty.
- Keep small parts out of reach of children.
- If you are unsure about any step of the installation process, consult a qualified professional.
Included Components
The package for the Tesa Assa Abloy Lock Model 4240303NI typically includes the following items:
- Lock mechanism
- Security shield (Coat of Arms of security)
- Reinforced hook with two steel plates
- Stainless steel front and locking components
- Fasteners for installation
- Mounting instructions
Note: This lock is supplied without a cylinder. A compatible cylinder must be purchased separately.
Setup and Installation
Follow these steps for proper installation of your Tesa Assa Abloy lock:
- Prepare the Door/Profile: Ensure the door or metallic profile is prepared according to the lock's dimensions. The lock is designed for European profiles with a camera, featuring a box of less than 15 mm. Refer to the technical drawing for precise measurements.
- Insert the Lock Body: Carefully insert the lock body into the prepared mortise in the door or profile. Ensure it sits flush and is correctly oriented.
- Secure the Lock Body: Use the provided fasteners to secure the lock body in place. Do not overtighten.
- Install the Front Plate: Attach the stainless steel front plate to the edge of the door, aligning it with the lock body. Secure with appropriate screws.
- Install the Security Shield: Position the security shield (Coat of Arms of security) on the exterior side of the door, aligning it with the cylinder opening. Secure it according to its specific instructions, ensuring it provides maximum protection.
- Install the Cylinder (Sold Separately): Insert a compatible cylinder into the lock mechanism. Secure the cylinder with the retaining screw through the lock's front plate.
- Test Operation: Before closing the door, test the lock's operation with the key. Ensure the reinforced hook and latch bolt extend and retract smoothly.

Figure 1: Technical drawing illustrating the dimensions and components of the Tesa Assa Abloy Lock Model 4240303NI. This diagram provides critical measurements for mortise preparation and component alignment during installation.

Figure 2: Side view of the Tesa Assa Abloy Lock Model 4240303NI, highlighting the profile and keyhole. This view helps in understanding the lock's depth and how it integrates into the door or metallic profile.
Operating Instructions
The Tesa Assa Abloy Lock Model 4240303NI operates via a key unlock mechanism.
- Locking: Insert the key into the cylinder and turn it to extend the reinforced hook and latch bolt, securing the door.
- Unlocking: Insert the key into the cylinder and turn it in the opposite direction to retract the reinforced hook and latch bolt, allowing the door to open.
- Smooth Operation: Ensure the key turns smoothly without excessive force. If resistance is felt, do not force the key; investigate the cause.
Maintenance
Regular maintenance ensures the longevity and reliable operation of your lock.
- Cleaning: Clean the exterior surfaces of the lock and front plate with a soft, damp cloth. Avoid abrasive cleaners or solvents that could damage the finish of the alloy steel and stainless steel components.
- Lubrication: Periodically apply a small amount of graphite-based lubricant or a specialized lock lubricant into the keyway of the cylinder. Do not use oil-based lubricants, as they can attract dust and grime.
- Inspection: Regularly inspect the lock for any signs of wear, damage, or loose fasteners. Tighten any loose screws.
- Door Alignment: Ensure the door remains properly aligned within its frame. Misalignment can cause undue stress on the lock mechanism and affect its operation.
Troubleshooting
If you encounter issues with your Tesa Assa Abloy lock, refer to the following common problems and solutions:
- Key is difficult to turn or sticks:
- Apply lock lubricant to the keyway.
- Check if the key is bent or damaged. Use a spare key if available.
- Ensure the cylinder retaining screw is not overtightened.
- Latch bolt or hook does not extend/retract fully:
- Check for obstructions in the strike plate or mortise.
- Verify that the door is properly aligned and not sagging.
- Inspect the lock mechanism for any visible damage or debris.
- Lock feels loose in the door:
- Tighten all mounting screws for the lock body and front plate. Do not overtighten.
If problems persist after attempting these solutions, contact customer support or a qualified locksmith.
Specifications
| Feature | Specification |
|---|---|
| Brand | Tesa Assa Abloy |
| Model Number | 4240303NI |
| Special Feature | Key Unlock |
| Lock Type | Sicherheitsschloss (Security Lock) |
| Item Dimensions (L x W x H) | 9.65 x 1.97 x 1.57 inches (24.5 x 5.0 x 4.0 cm) |
| Material | Alloy Steel, Stainless Steel |
| Item Weight | 0.51 Kilograms (1.12 lbs) |
| Color | Grau (Rostfrei) / Grey (Stainless) |
| Included Components | Lock, Security Shield, Fasteners, Mounting Instructions |
| Cylinder | Not Included |
Warranty and Support
For warranty information and customer support regarding your Tesa Assa Abloy Lock Model 4240303NI, please refer to the documentation provided with your purchase or visit the official Tesa Assa Abloy website. Keep your proof of purchase for warranty claims.
If you require technical assistance or have questions not covered in this manual, please contact Tesa Assa Abloy customer service directly.