Ajax Superior DoorProtect Flush (3EOL) is a wired 3EOL opening detector with anti-sabotage features. The device is available in two versions: Ajax Superior DoorProtect Flush (3EOL) for concealed mounting and Ajax Superior DoorProtect Flush (3EOL) with Surface-mount kit for either concealed or surface mounting. Surface-mount kit can be purchased separately.
Ajax Superior DoorProtect Flush (3EOL) is a device of the Superior product line. Only accredited Ajax Systems partners can sell, install, and maintain Superior products.
Functional elements
Ajax Superior DoorProtect Flush (3EOL)


- Cable.
- Detector.
- Detector flush-mount enclosure.
- Holes for securing the flush-mount enclosure to a surface.
- Magnet flush-mount enclosure for installing on a ferromagnetic surface.
- Magnet flush-mount enclosure for installing on a non-ferromagnetic surface.
- Neodymium magnet.
Surface-mount kit
- Detector surface-mount enclosure.
- Magnet surface-mount enclosure.
- Recesses for aligning the spacers with surface-mount enclosures.
- Holes for securing the surface-mount enclosures to a surface.
- Latches for securing the surface-mount covers to the mounting panels.
- Detector mounting panel.
- Place for installing the detector.
- Magnet mounting panel.
- Place for installing the magnet.
- Recesses for cutting holes to route the cable from the side of the surface-mount enclosure. Recesses are provided on each side.
- Spacer 0.08″ — 4 pcs (included in the complete set).
- Spacer 0.24″ — 1 pc (included in the complete set).
Compatible integration modules
Ajax Superior DoorProtect Flush (3EOL) requires an integration module that supports 3EOL connections. The detector can be connected to an Ajax integration module or a third-party integration module if the detector is not used in an Ajax system.
Operating principle
Ajax Superior DoorProtect Flush (3EOL) consists of two parts: a detector with two reed switches and a neodymium magnet required to detect opening. The first reed switch detects door or window opening and closing events, while the second reed switch detects magnetic masking attempts.
The opening reed switch changes its contact state when the magnet approaches or moves away from it, while the magnetic masking reed switch changes its contact state when an intruder places a strong sabotage magnet near the detector.
The 3EOL device connection type is based on measuring the total loop resistance to determine the device state and events. The device can detect the following events: door opening/closing, magnetic masking, line short circuit, and line break.
The wiring diagram below shows the device's switches and resistors in the loop.

The device can have the following states:
Door open. The magnet is far from the detector:
- NO reed switch (masking) — open → 9.1 kΩ resistor is in the loop
- NO reed switch (opening) — open → 4.7 kΩ resistor is in the loop
Total loop resistance: 16.0 kΩ.
Door closed. The magnet is close to the detector:
- NO reed switch (masking) — open → 9.1 kΩ resistor is in the loop
- NO reed switch (opening) — closed → shunts the 4.7 kΩ resistor
Total loop resistance: 11.3 kΩ.
Magnetic masking. If an intruder places their own strong magnet near the detector to keep the opening NO reed switch closed, the masking NO reed switch also responds to this magnet and closes. As a result, the loop resistance changes to an atypical value, and the system triggers a masking alarm. The reed switches operate as follows:
- NO reed switch (masking) — closed → shunts the 9.1 kΩ resistor
- NO reed switch (opening) — closed → shunts the 4.7 kΩ resistor
Total loop resistance: 2.2 kΩ.
Line integrity. The line is shorted or broken:
- Line short circuit — zero resistance in the loop
- Line break — infinite resistance in the loop
All device states and loop resistances are listed in the table below.
State | Resistance, kΩ |
|---|---|
Door open | 16.0 |
Door closed | 11.3 |
Magnetic masking | 2.2 |
Short circuit | 0 |
Line break | Infinity |
In an Ajax system, if the device in armed mode detects a door or window being opened or closed, it instantly sends an alarm to the hub via the integration module. The hub activates the sirens added to the system, runs scenarios, and notifies users and the monitoring company of the event. All device events are recorded in the event feed in Ajax apps.
The detector does not switch to armed mode instantly. The switching time depends on the exit delay (specified in the detector settings) and the integration module polling interval. The polling interval is set in Jeweller or Jeweller/Fibra settings and defaults to 36 seconds. In the first case, the delay is set by a user or PRO with admin rights. In the second case, the delay occurs because the hub takes one polling interval to notify the detector of the security mode change.
If a sabotage magnet is detected, users and the monitoring station receive a masking notification. The system allows users to select when the device should detect magnetic masking: always or only when the detector is in armed mode.
Sending events to the monitoring station
An Ajax system can transmit alarms to the Ajax PRO Desktop app and the monitoring station in the formats of SurGard (Contact ID), SIA (DC-09), ADEMCO 685, and other protocols.
The device connected to an Ajax integration module can transmit the following events:
- Opening sensor (opening NO reed switch) alarm / recovery.
- Magnetic masking sensor (masking NO reed switch) alarm / recovery.
- Line break / recovery (tamper alarm / recovery).
- Line short circuit.
- Permanent deactivation / activation of the device.
- One-time deactivation / activation of the device.
When an alarm is received, a monitoring station operator knows what has happened and exactly where to dispatch a rapid response unit. Ajax device addressability allows sending events to Ajax PRO Desktop and the monitoring station with the device type, name, security group, and virtual room specified. The list of transmitted parameters may vary depending on the monitoring software type and the selected communication protocol.
You can find the device ID and loop (zone) number in the device states. The device number corresponds to the loop (zone) number.
Selecting an installation site
When choosing a location for installing Ajax Superior DoorProtect Flush (3EOL), consider the parameters that affect its operation:
- Surface material (ferromagnetic or non-ferromagnetic).
- Distance between the detector and the magnet.
- Levelness of the surfaces on which the detector and the magnet are installed.
When designing the system, be sure to follow the placement recommendations. Only qualified professionals can design and install an Ajax system. A list of recommended partners is available here.
Installation recommendations
The magnet position relative to the detector depends on the installation type and location, as well as the surface material. For any installation type, the detector and the magnet must be positioned exactly opposite each other and at the same level.
The detector must be installed on the fixed part of the door/window (e.g., the frame), while the magnet must be installed on the movable part.
Do not exceed the maximum permissible distance between the detector and the magnet. This may cause false alarms or detector malfunctions: the detector will not respond to door/window closing and opening.
Concealed (flush) mounting on ferromagnetic surfaces
If the detector is installed on a ferromagnetic surface:
- The distance between the detector and the magnet must not exceed 3 mm 0.12 inch.
- To install the magnet, use the flush-mount enclosure for mounting on ferromagnetic surfaces (the smaller one).
- The distance between the detector and a third-party electromagnet (such as a magnetic door lock) must be greater than 4 inches.

Concealed (flush) mounting on non-ferromagnetic surfaces
If the detector is installed on a non-ferromagnetic surface:
- The distance between the detector and the magnet must not exceed 0.12 inch.
- To install the magnet, use the flush-mount enclosure for mounting on non-ferromagnetic surfaces (the bigger one).
- The distance between the detector and a third-party electromagnet (such as a magnetic door lock) must be greater than 4 inches.

Surface mounting on ferromagnetic surfaces
If the detector is installed on a ferromagnetic surface:
- The distance between the detector and the magnet must not exceed 0.12 inch.
- To install the detector and the magnet, use the spacers.
- The distance between the detector and a third-party electromagnet (such as a magnetic door lock) must be greater than 4 inches.

Surface mounting on non-ferromagnetic surfaces
If the detector is installed on a non-ferromagnetic surface:
- The distance between the detector and the magnet must not exceed 0.12 inch.
- The distance between the detector and a third-party electromagnet (such as a magnetic door lock) must be greater than 4 inches.

How not to install the device
- With the magnet installed at a distance that does not comply with the recommendations. This may result in false alarms or detector malfunctions: the detector will not respond to door/window closing and opening.
- On ferromagnetic surfaces without using the spacers (only for surface mounting).
- In premises with temperature and humidity beyond the permissible limits. This may damage the device.
- Near other magnets. This may result in false alarms caused by magnetic masking detection.
- Asymmetrically positioned relative to the magnet.
Preparing for installation
Cable arrangement
When preparing to run cables, check the electrical and fire safety regulations in your region. Strictly follow these standards. Tips for running cables are available in the article.
Cable routing
Before installation, refer to the Selecting an installation site section. Do not deviate from the system design. Failure to follow the basic installation rules and the recommendations in this manual may result in incorrect operation or loss of connection to the device.
Ensure a minimum distance of 20 inches between device signal cables and power cables when routing them in parallel. If the cables cross, maintain a 90° angle between them. Observe the permissible cable bending radius. Otherwise, there is a risk of damaging or breaking the conductor. Tips for cable routing are available in this article.
Preparing cables for connection
The detector is supplied with a 32.8 ft connection cable. To prepare the cable, remove the cable insulation layer and strip the wires with a special insulation stripper. The wire ends inserted into the device terminals must be tinned or crimped with a sleeve. This ensures a reliable connection and protects the conductor from oxidation. Tips for preparing the cables are available in the article.
Installation
Before installing Ajax Superior DoorProtect Flush (3EOL), ensure that you choose an optimal installation site that complies with the requirements specified in this user manual.
The detector must be installed on the fixed part of the door/window (e.g., the frame), while the magnet must be installed on the movable part.
Concealed (flush) mounting
Drill holes of the following dimensions in the door edge and the door frame:
⌀10 × 30 mm — for the detector
⌀10 × 10 mm — for the magnet, if installed on a ferromagnetic surface
⌀10 × 18 mm — for the magnet, if installed on a non-ferromagnetic surface
⌀0.39″ × 1.18″ — for the detector
⌀0.39″ × 0.39″ — for the magnet, if installed on a ferromagnetic surface
⌀0.39″ × 0.71″ — for the magnet, if installed on a non-ferromagnetic surface

Check the cable path and prepare all necessary holes for cable routing. The cable dimensions are as follows:
⌀3 mm +0.2 mm, 10 m length
⌀0.12″ +0.008″, 32.8 ft length
Install the detector in the detector flush-mount enclosure.

Install the magnet in the magnet flush-mount enclosure. Use the magnet enclosure designed for the type of door material on which the device is installed.

Route the detector cable according to the planned path.
Install the detector at the prepared location and secure it with the bundled screws using all fixing points.

Install the magnet at the prepared location and secure it with the bundled screws using all fixing points.

Ensure that the detector and the magnet are installed according to the Installation recommendations.
Connect the detector cable to the integration module. One wire must be connected to the zone terminal, and the other to the COM terminal. Use any available zone terminal.


For more information, refer to the user manual of the integration module to which the device is connected. User manuals for Ajax integration modules are available on the Ajax Support page.
Add the device to the system: add it to the integration module and configure its settings.
Run the device functionality test.
Surface mounting
Place the detector and magnet surface-mount enclosures at the planned installation location to check the installation layout. Check how cables would be routed. Use the spacers if the device is to be installed on a ferromagnetic material or to align the detector with the magnet.
Open the detector and magnet surface-mount enclosures by pushing the release latches and removing the mounting panels.

Secure the detector mounting panel to the surface with the bundled screws using all fixing points. Use the spacers if necessary.
Secure the magnet mounting panel to the surface with the bundled screws using all fixing points. Use the spacers if necessary.
Insert the detector and the magnet in the corresponding mounting panels.

Route the detector cable according to the planned path.
If the cable must be routed from the side of the detector, make an appropriate hole in the detector cover.
Install the detector and magnet covers.

Ensure the detector and the magnet are installed according to the Installation recommendations.
Connect the detector cable to the integration module. One wire must be connected to the zone terminal, and the other to the COM terminal. Use any available zone terminal.


For more information, refer to the user manual for the integration module to which the device is connected. User manuals for Ajax integration modules are available on the Ajax Support page.
Add the device to the system: add it to the integration module and configure its settings.
Run the device functionality test.
Adding to the system
If the device is used in an Ajax system, follow the steps in the subsections below to add the device. If the device is used in a third-party system, refer to the instructions for adding the device to that system.
Before adding the device
- Install an Ajax app.
- Log in to a PRO account or create a new one.
- Select a space or create a new one.
- Add at least one virtual room.
- Add a compatible hub to the space. Ensure the hub is switched on and has internet access via Ethernet, Wi-Fi, and/or mobile network.
- Check the states in the Ajax app to ensure that the space is disarmed and the hub is not starting an update.
- Add the Ajax integration module to the system.
Adding the device to the Ajax integration module
- In an Ajax app, go to the Devices
tab.
- Find the integration module to which the device is connected.
- Select Devices under the module tile.
- Tap Add device.
- Enter a name for the device.
- Select the wired input to which the device is physically connected.
- Select a virtual room.
- Tap Add device. The device will be added within 30 seconds.
The device state update interval depends on the Jeweller or Jeweller/Fibra settings and defaults to 36 seconds.
If the connection attempt fails, ensure that the wired connection is set up correctly before trying again. If the maximum number of devices has already been added to the hub, an error notification appears when you try to add another device.
Setting up the device
Once the device is connected and added to the Ajax integration module, configure it to ensure correct operation.
To configure the device, in an Ajax app:
- Go to the Devices
tab.
- Find the integration module to which the device is connected.
- Select Devices under the integration module tile.
- Select the device from the list.
- Go to Settings
and configure the device according to the table below.
Sensor number | Setting | Value |
|---|---|---|
N/A | Input type | 3EOL |
Sensor 1 | Type of event | Tamper alarm |
Operating mode | Bistable | |
R1 resistance | 2.2 kΩ | |
Always active | Enabled | |
Sensor 2 | Sensor mode | Detect alarms |
Type of event | Intrusion | |
Default state | Normally closed | |
Operating mode | Bistable | |
R2 resistance | 4.7 kΩ | |
Always active | Enabled or disabled | |
Sensor 3 | Type of event | Masking |
Default state | Normally open | |
Operating mode | Bistable | |
R3 resistance | 9.1 kΩ | |
Always active | Enabled or disabled |
Functionality testing
To perform the detection test, trigger the device. For example, open and close the door to test the opening sensor, or bring the sabotage magnet close to the detector to check the masking sensor. The sensor states will be displayed in the device states in the Ajax app.
Icons
The following device icons are only available when the device is connected to an Ajax integration module.
Icon | Meaning |
|---|---|
The Chime feature is enabled. | |
Entry/Exit delay is enabled. | |
The device operates in Always active mode. | |
The device operates when Night mode is enabled. | |
Reporting to the monitoring station is deactivated for the device. | |
The state of the device's tamper button is OK. | |
Device tamper alarm. | |
The state of the intrusion sensor is OK (the door/window is closed). | |
Intrusion alarm (the door/window is opened). | |
The state of the masking sensor is OK. | |
Masking alarm. | |
The device is automatically disabled because the maximum number of alarms has been exceeded. | |
The device is automatically disabled when the restoration timer expires. | |
The device is disabled by a system user. | |
The device is disabled until the system is disarmed. |
States
The following device states are only available when the device is connected to an Ajax integration module.
The states include information about the connected device and its operating parameters. You can view the device states in Ajax apps:
- Go to the Devices
tab.
- Find the integration module to which the device is connected.
- Select Devices under the integration module tile.
- Select the device from the list.
Parameter | Meaning |
|---|---|
Malfunction | Tapping The field is displayed only if a malfunction is detected. |
Name of the integration module | Connection state between the integration module and the connected device:
|
Tamper sensor | State of the device's tamper sensor:
|
Intrusion sensor | State of the device's opening sensor:
|
Masking sensor | State of the device's masking sensor:
|
Always active sensors | Shows the device's sensors that operate in Always active mode. |
Device resistance | The total resistance of the device circuit at the moment. Measured automatically by the integration module. |
Permanent deactivation | The field shows the state of the device's permanent deactivation setting:
You can also configure device deactivation:
The feature is configured in Ajax PRO apps. |
One-time deactivation | State of the device's one-time deactivation setting:
|
Alarm response | |
Operating mode | Shows how the device responds to alarms:
|
Entry delay | Entry delay (alarm activation delay) is the time a user has to disarm the system after entering the premises. |
Exit delay | Exit delay (arming delay) is the time a user has to leave the premises after the system is armed. |
Arm in Night mode | When the option is enabled, the device will enter armed mode when the system is set to Night mode. |
Entry delays in Night mode | Entry delay (alarm activation delay) in Night mode is the time a user has to disable Night mode after entering the premises. |
Exit delays in Night mode | Exit delay (arming delay) in Night mode is the time a user has to leave the premises after Night mode is enabled. |
Night mode delay | Entry delay in Night mode when the device is set to the Follower operating mode. It is the time a user has to disable Night mode (alarm activation delay) after the Entry/Exit device is triggered. |
Wire input | The number of the integration module zone to which the device is connected. |
Device No. | The device loop (zone) number. |
Settings
The following device settings are only available when the device is connected to an Ajax integration module.
To change the device settings, in an Ajax app:
- Go to the Devices
tab.
- Find the integration module to which the device is connected.
- Select Devices under the integration module tile.
- Select the device from the list.
- Go to Settings
.
- Configure the required settings.
- Tap Back to save the new settings.
Setting | Meaning |
|---|---|
Name | The device name. Displayed in the list of hub devices, SMS, and notifications in the event feed. To change the name, tap on the text field. The name can contain up to 24 Latin characters or up to 12 Cyrillic characters. |
Room | Selecting the virtual room to which the device is assigned. The room name is displayed in the text of SMS and notifications in the event feed. |
Input type | Selecting the device connection type. The 3EOL option must be selected for this setting. |
Connection diagram | Displays the wiring diagram for connecting a device to the integration module. It is used as a reference for an installer. |
Measure sensor resistance | Allows a user to open a wizard that automatically measures the resistance of a resistor connected to the device. |
Sensor 1 By default, the state of contacts for Sensor 1 is normally closed. | |
Type of event | The event type for the connected device. The Tamper alarm option must be selected for this setting. The text of notifications in the event feed and SMS, as well as the code transmitted to monitoring software, depends on the selected event type. |
Operating mode | The operating mode for the connected device. The Bistable option must be selected for this setting. |
R1 resistance | The resistance of a resistor connected to Sensor 1. Measured automatically. The 2.2 kΩ value must be selected for this setting. |
Always active | When the option is enabled, the device connected to the integration module constantly detects threats and reports alarms. This option must be enabled for Sensor 1. |
Sensor 2 | |
Sensor mode | The sensor mode for the connected device. The Detect alarms option must be selected for this setting. |
Type of event | The event type for the connected device. The Intrusion option must be selected for this setting. The text of notifications in the event feed and SMS, as well as the code transmitted to monitoring software, depends on the selected event type. |
Default state | The normal contact state for the connected device (when the magnet is present). The Normally closed option must be selected for this setting. |
Operating mode | The operating mode for the connected device. The Bistable option must be selected for this setting. |
R2 resistance | The resistance of a resistor connected to Sensor 2. Measured automatically. The 4.7 kΩ value must be selected for this setting. |
Always active | When the option is enabled, the device connected to the integration module constantly detects threats and reports alarms. |
Sensor 3 | |
Type of event | The event type for the connected device. The Masking option must be selected for this setting. The text of notifications in the event feed and SMS, as well as the code transmitted to monitoring software, depends on the selected event type. |
Default state | The normal contact state for the connected device (when the magnet is present). The Normally open option must be selected for this setting. |
Operating mode | The operating mode for the connected device: The Bistable option must be selected for this setting. |
R3 resistance | The resistance of a resistor connected to Sensor 3. Measured automatically. The 9.1 kΩ value must be selected for this setting. |
Always active | When the option is enabled, the device connected to the integration module constantly detects threats and reports alarms. |
Pulse time | Device pulse time for alarm activation:
An alarm will be activated if the pulse from the device lasts longer than specified in this setting. This can be used to filter out false alarms. |
Alert with siren if Sensor 1 is triggered | When the option is enabled, the sirens added to the system will sound if Sensor 1 raises an alarm. |
Alert with siren if Sensor 2 is triggered | When the option is enabled, the sirens added to the system will sound if Sensor 2 raises an alarm. |
Alert with siren if Sensor 3 is triggered | When the option is enabled, the sirens added to the system will sound if Sensor 3 raises an alarm. |
Alert with siren if device is shorted out | If the option is enabled, the sirens connected to the system are activated when a short circuit is detected. |
Chime settings | Configuring the Chime feature. It is available only for devices operating in Bistable mode. The feature is not available for sensors in Pulse mode or Always active mode. |
Alarm response | |
Operating mode | Selecting how this device will respond to alarms:
|
Entry delay | Entry delay: 5 to 255 seconds. Entry delay (alarm activation delay) is the time a user has to disarm the system after entering the premises. |
Exit delay | Exit delay: 5 to 255 seconds. Exit delay (arming delay) is the time a user has to leave the premises after the system is armed. |
Arm in Night mode | When this option is enabled, the detector will enter the armed mode if the system is set to Night mode. |
Entry delays in Night mode | Entry delay in Night mode: 5 to 255 seconds. Entry delay (alarm activation delay) in Night mode is the time a user has to disable Night mode after entering the premises. |
Exit delays in Night mode | Exit delay in Night mode: 5 to 255 seconds. Exit delay (arming delay) in Night mode is the time a user has to leave the premises after Night mode is enabled. |
Night mode delay | Delay time in Night mode: 5 to 255 seconds. It is the time a user has to disable Night mode (alarm activation delay) after the Entry/Exit device is triggered. The setting is displayed if the device is set to the Follower operating mode and the Arm in Night mode option is enabled. |
Monitoring | Allows a user to open the monitoring setting menu:
Monitoring settings are available only in Ajax PRO apps. |
Permanent deactivation | Allows a user to disable the device without removing it from the system. Two options are available:
A user can also configure device deactivation:
The feature is configured in Ajax PRO apps. |
One-time deactivation | Allows a user to disable the device until the system is disarmed. Two options are available:
|
Delete device | Allows a user to delete the device from the module. |
Chime on opening
This functionality is only available when the device is connected to an Ajax integration module.
Chime is an audible signal that informs users when opening detectors are triggered while the system is disarmed. The feature is used, for example, in stores to alert employees when someone enters the premises.
The feature is configured in two stages: setting up the sirens and setting up the opening detectors.
Configuring a device connected to the integration module
- Go to the Devices
tab.
- Find the integration module to which the device is connected.
- Tap Devices under the integration module tile.
- Select the device from the list.
- Go to the device Settings .
- Select the Chime settings option.
- Enable the If device is triggered option.
- Adjust the chime sound: 1 to 4 short beeps. Once the sound is selected, the Ajax app will play it.
- Tap Back to apply the settings.
Ensure the Chime feature is enabled for the required siren in its Beep settings.
Indication
The device has no indication.
Malfunctions
When a malfunction occurs, the integration module to which the device is connected can identify the type of malfunction according to the configured sensor settings for the 3EOL connection.
If the device is connected to an Ajax integration module, a malfunction counter is displayed in the upper-left corner of the device icon in the Ajax app. Users can view malfunctions in the module states and the states of connected devices. Fields with malfunctions are highlighted in red.
A malfunction of the connected device is displayed if:
- There is no connection between the integration module and the device (the tamper button has been triggered or the contacts are damaged).
- The system has detected a short circuit in the device contacts.
The system can report malfunctions to the monitoring station, as well as to users via push notifications and SMS.
Maintenance
Regularly check the device's functionality. The recommended check interval is once every three months. Clean the device enclosure from dust, cobwebs, and other contaminants as needed. Use a soft, dry cloth suitable for equipment care. Do not use substances containing alcohol, acetone, gasoline, or other active solvents to clean the device.
Technical specifications
Warranty
Warranty for products manufactured by Limited Liability Company "Ajax Systems Manufacturing" is valid for two years from the date of purchase.
If the device does not operate properly, we recommend contacting the support service first, as most technical issues can be resolved remotely.
Contact Technical Support:
- Telegram
- Phone: 0 (800) 331 911
Manufactured by "AS Manufacturing" LLC






