Dry contact relay to control 12-24 V⎓ power supply remotely


Relay contacts can switch current of up to 5 A in a range of 0–36 V⎓, and up to 3 kW in a 110–230 V~ network. The contacts are not connected to the device galvanically, so they can be connected to the input control circuits of various equipment, emulating a button or a toggle switch. The device body is quite miniature – 39 × 33 × 18 mm – Relay can easily be installed in a junction box, electrical panel, or switch.

Relay closes and opens contacts by the user command in the Ajax app. You can also set Relay automatic switching on or off in response to arming or disarming the system, an alarm, Button press, or schedule.

👉 How to create and configure a scenario in the Ajax security system.

In addition to switching the state of contacts, the Ajax app allows real-time monitoring of the power supply voltage of the relay or devices connected through it, if they are powered from the same source. If the relay and the connected device are powered from different sources, then the app displays only the voltage of the relay power supply.

Connecting to the same power source
Connecting to separate power sources
Connecting as a button/switch


Our Relay supports several different relay modes of operation and various states of contact. They can be combined depending on user needs.

Bistable, when the contacts close and open as a switch.

Pulse, when the contacts close or open for 0.5 to 255 seconds (up to 15 seconds if Relay has a firmware version below, and then automatically execute the action in reverse.


Gates and traffic barriers. Opened by a single click in the Ajax Security System mobile app, which means no more pesky key ring. The app is also password and fingerprint protected, so unauthorized persons can’t access it without your permission.

Roller blinds and curtains. Can be automatically opened and closed when people come home or leave for the office.

Electric locks. Locked when the system is armed and opened after disarming.

How to control remotely an electric lock with Ajax Relay

Routers. If network equipment is connected through the Relay, an unresponsive router can be restarted directly from your smartphone. The hub will even continue to operate through the GSM channel and intercept the connection via Ethernet after the router is restarted.

Electric Valves. These valves help shut off water and gas supply remotely in the event of an accident when you are away. They also disconnect utilities automatically when you go to work or on vacation.

How can water shut off be controlled using the Ajax security system


Relay is a low-current relay for remote control of equipment. The device operates at a 7–24 V⎓ supply voltage.

The relay features dry contacts that are electrically isolated to the power supply circuit of the device. This allows using Relay in both low-voltage and domestic power networks.

Relay is designed for controlling anti-flood systems, electric locks, access control systems, security smoke machines, roller shutters, and other devices.

Learn more

WallSwitch is a power relay that can remotely control 110/230 V~ power supply.

This relay does not have galvanic isolation and switches the power received at the input.

WallSwitch is designed for installation in a socket box or for controlling the power supply of lighting, gates, barriers of video surveillance systems, and other devices that obtain power from 110/230 V~ mains.

Learn more


To install Relay or WallSwitch on a DIN rail, use a DIN Holder bracket.


The identifier (ID) is the serial number of the device. It is located under the QR code on the body, board, and packaging of the device.

ID at the bottom of the box

ID under the lid

The ID can also be found in the device states in the Ajax app.

  1. Sign in to the Ajax app.
  2. Select the required hub from the list if you have several of them or if you are using a PRO app.
  3. Go to the Devices menu.
  4. Select a device from the list. Device ID information is located at the bottom of the status screen.

You can do it in Relay settings:

  1. Ajax app
  2. Devices
  3. Select the device
  4. Settings
  5. In the Contact state field, select the required option: Normally Closed or Normally Open

With OS Malevich 2.9 update, permanent deactivation of devices without removing them from the system has become available.

Deactivation may be necessary if the device is incorrectly installed or configured, loses connection with the hub, or has failed.

To deactivate a device, in the Ajax app:

  • Select a hub if you have several of them or if you are using the PRO app.
  • Go to the Devices menu.
  • Select the device from the list.
  • Go to its Settings .
  • Select the type of permanent deactivation:
    • Entirely — the device does not execute system commands or run automation scenarios, and the system ignores device alarms and other notifications.
    • Lid only — the system ignores the notifications on the detector’s tamper button triggering.

Several operating modes and various contact states (normally closed or normally opened) are available for automation devices.

They can be combined depending on the wiring diagram and the type of detector that the device controls:

  • bistable, when the contacts close and open according to the switch principle;
  • pulse, when the contacts close or open for a time from 0.5 to 255 seconds, and then automatically perform the opposite action.

Pulse mode is available for WallSwitch and Socket with firmware version or higher.


To avoid accidents and equipment failures, we equipped our Relay mechanism with protection against overheating and voltage surges. It is permanently enabled and can’t be disabled. If the temperature where the Relay is installed exceeds 65°C, or 85°C inside the device, the relay opens and sends out an alarm. As soon as the temperature returns to normal, the relay releases and sends out the respective notification.

There are two threshold values for the supply voltage: the lower value is 6.5 V⎓, and the upper value is 36.5 V⎓. If the power level is too high or too low, protection is activated, the device is disabled and a warning message is sent out. After the supply voltage parameters return to normal, the relay releases and notifies users.


By default, the hub is set to a hub–detector ping interval of 36 seconds and 30 undeliverable data packets to consider the device lost. With these settings, the hub will detect the loss of the detector in 18 minutes.

To reduce this time, go to the hub settings in the Jeweller section and change the settings. The minimum time for detecting loss of connection with the device is 36 seconds (3 polls of 12 seconds each).

The time before raising the alarm by the communication loss between hub and device is calculated with the following formula:

Detector Ping Interval × Number of missed pings to determine connection failure

Note that with the minimum ping interval, short-term interference can lead to loss of connection with the device. Therefore, set the minimum values only if it is critically important to promptly inform about events in the system.


The loop (zone) number is required to describe all devices connected to the hub when adding a protected facility to the security company monitoring station.

The number is assigned when adding a device to the hub. The first added device has the first loop (zone) number. After removing the device from the system, its number becomes available. This number can be assigned to the next device to be added to the system.

The loop (zone) number is available in the states of each device in the Ajax app:


The firmware version can be found in the device states in the Ajax app.

  1. Sign in to the Ajax app.
  2. Select the required hub from the list if you have several of them or if you are using a PRO app.
  3. Go to the Devices menu.
  4. Select a device from the list. The firmware version information is located on the status screen at the bottom.

Go to the Devices tab , select the device you want to check.

ajax security system application

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