In addition to theft and fire protection, the Ajax security system can prevent site flooding attributed to pipe breaks or failures of plumbing fixtures. In order to implement the anti-flood system, you will need a LeaksProtect water leakage detector, a compatible electric valve as well as a WallSwitch relay or Relay. Using the relay, you can shut off the water supply manually—with the app—or automatically: by the alarm of the leak detector, by schedule, or by changing the security mode.
Only a qualified electrician can implement installation of the WallSwitch and the Relay! Regardless of the type of electrical circuit that accommodates the device.
The relay is used to open and close electrical circuits and can be used to control the power supply of electrical appliances.
- Relay — is a low-current remote control relay with a voltage-free “dry contact”.
- WallSwitch — is a PCB relay for remote control of power featuring an electric power meter.
Both devices are remotely controlled via the Ajax application. The application allows you to set up automatic closing and/or opening of the relay contacts when changing the armed state and using the “night mode”.
Choosing an electric valve to shut off the water
The electric valve opens and shuts off water supply when it receives an electrical signal. When choosing an electric valve, pay attention to the following parameters:
- Pipe diameter and threaded connection type of the fitting.
- Valve type. Valves are either normally closed or normally open. There are also special electric valves with two stable states that alternate when a DC pulse is applied.
Normally closed valves are usually used. They shut off water when external power is lost. Normally open valves remain open when power is lost.
- Power supply voltage. Electric valves operate at different DC and AC voltages: 230 V АС, 24 V AC, 24 V DC, 12 V DC, etc.
- Manual control. The rotating mechanism provides manual control of the electric valve similar to a common tap. This allows you to shut off the water even if the phone is not available.
- The number of control inputs — one or two control inputs or controlled by polarity inversion of the electrical signal at the input.
In order to implement the water shut off system based on the Ajax system, it is recommended to use normally closed valves with one control input — no coupling relays are required to connect the valves of this type. If you use pulse valves, the Ajax application will not know the valve state: open or closed. The Relay uses electric valves operating at 12/24 V, the WallSwitch — 230 V.
The valve should have two power supply sources: the main power source (electricity grid) of the site and backup from the battery. In this case, you will be able to shut off the water even if the building is disconnected. It is easier and cheaper to provide 12/24 V backup power supply rather than 230 V.
Layout diagram of the Relay connection to a 12/24 V electromagnetic valve
During mounting and operating, follow the general electrical safety rules when using electrical appliances as well as the requirements of electrical safety laws and regulations.
When power is lost, the Relay contacts remain in the open state. After the external power is restored, the Relay contacts restore their initial state.
Connection to the electric valve featuring one control input
In order to implement connection according to the diagram, it is necessary to provide a 12/24 V external power source!
The Relay and the electric valve can be powered from a single power supply source. When mounting the device, do not allow any moisture to penetrate the Relay or the site of cable connections.
- Connect the power supply source to the power terminals of the relay.
- Connect the “positive” contact terminal of the power source to one of the relay contact terminals, and the “positive” contact (control input) of the electromagnetic valve — to the other relay contact terminal.
- Connect the “negative” contact terminal of the electromagnetic valve to the “negative” contact terminal of the power source.
Such connection ensures closing of the electromagnetic valve using the Relay.
Valve examples:
- PIE T20-S2-B
- CONVA A20-T25-S2-C
- Ebowan 12 V DC
Operation of the 12/24 V DC electromagnetic valve featuring one control input
Relay set up
- Go to the Devices tab .
- Go to the Relay menu, then to Settings and select Bistable operation mode, and set the Initial state of contact terminals — Normally open.
Connection to the electric valve featuring two control inputs
In order to implement connection according to the diagram, it is necessary to provide a 12/24 V external power source and a SPDT-type coupling relay (12/24 V)!
Relay, coupling relay, and electric valve can be powered from a single power source. When mounting the device, do not allow any moisture to penetrate the Relay, coupling relay, or the site of cable connections.
- Connect the power supply source to the power terminals of the Relay.
- Connect the “positive” contact terminal of the power source to one of the Relay contact terminals, and the “positive” contact terminal of the coupling relay — to the other Relay contact terminal.
- Connect the “negative” contact terminal of the electromagnetic valve (common contact) and the “negative” contact terminal of the coupling relay to the “negative” contact terminal of the power source.
- Connect the “COM” contact terminal of the coupling relay to the “positive” contact terminal of the power source.
- Connect the “NC” contact terminal of the coupling relay to the control opening input of the electric valve, and the “NO” contact terminal — to the closing input.
Such connection ensures closing of the electromagnetic valve using the Relay.
Valve examples:
- Neptun Bugatti PRO 12 V (Neptun)
Operation of the 12/24 V DC electromagnetic valve featuring two control inputs
Relay set up
- Go to the Devices tab .
- Go to the Relay menu, then to Settings and select Bistable operation mode, and set the Initial state of contact terminals — Normally closed.
Connection to electric valve featuring “polarity inversion” control input
In order to implement connection according to the diagram, it is necessary to provide a 12/24 V external power supply source and a DPDT-type coupling relay (12/24 V)!
The Relay, coupling relay, and electric valve can be powered from a single power source. When mounting the device, do not allow any moisture to penetrate the Relay, coupling relay, or the site of cable connections.
- Connect the power supply source to the power terminals of the Relay.
- Connect the “positive” contact terminal of the power source to one of the Relay contact terminals, and the “positive” contact terminal of the coupling relay — to the other Relay contact terminal.
- Connect the “NO” contact terminal of the first relay to the “positive” contact terminal, and the “NC” contact terminal — to the “negative” contact terminal of the power source.
- Connect the “NO” contact terminal of the second relay to the “negative” contact terminal, and the “NC” contact terminal — to the “positive” contact terminal of the power source.
- Connect the “COM” contact terminal of the first coupling relay to the first control input, and the “COM” contact terminal of the second relay — to the second control input of the electric valve.
- Connect the “negative” contact terminal of the coupling relay to the “negative” contact terminal of the power source.
- Connect the “NC” contact terminal of the coupling relay to the first control input, and the “NO” contact terminal — to the second control input.
Such connection ensures operation of the coupling relay that supplies power of variable polarity to the electric valve control inputs using the Relay. The polarity of the input voltage determines the electric valve state: open or closed.
Valve examples:
- COVNA A20-T15-S2-C
- CVX-15N
Operation of the 12/24 V DC electromagnetic valve featuring polarity inversion control
The Relay set up
- Go to the Devices tab .
- Go to the Relay menu, then to Settings and select Bistable operation mode, and set the Initial state of contact terminals — Normally closed.
Layout diagram of the WallSwitch connection to a 230 V AC electromagnetic valve
During mounting and operating, follow the general electrical safety rules when using electrical appliances as well as the requirements of electrical safety laws and regulations.
Connection to the 230 V AC electric valve featuring one control input
In order to implement connection according to the diagram, it is necessary to provide a 230 V external power supply source!
The WallSwitch and electric valve can be powered from a single power supply source. When mounting the device, do not allow any moisture to penetrate the WallSwitch or the site of cable connections.
- Connect the power supply source to the power terminals of the WallSwitch observing the polarity.
- Connect the “N” output terminal (neutral) of the WallSwitch to the “N” contact terminal of the electric valve.
- Connect the “L” output terminal (phase) of the WallSwitch to the control input of the electric valve.
- Connect the “L” contact terminal of the electric valve to the 230 V phase of the power source.
- Ground the “PE” contact terminal of the electric valve.
Such connection ensures the closing of the electromagnetic valve using the WallSwitch. When the WallSwitch contacts close, the valve closes. When they open, the valve opens.
Some valves enable selection of the normal state: open or closed when control input is closed.
Valve examples:
- ESBE MBA 100 series
- HC220В
- 2W-160-15C
Operation of the 230 V AC electromagnetic valves featuring one control input
No additional WallSwitch set up via the application is required.
Click the switch in the WallSwitch line — the state of the relay contacts will change to the opposite.
When the WallSwitch contacts are closed, the electric valve is supplied with power and it closes. When contacts are opened, the control input is cut off and the electric valve opens.
Connection to the 230 V AC electric valve featuring two control inputs
In order to implement connection according to the diagram, it is necessary to provide a 230 V external power supply source and a SPDT-type coupling relay (230 V)!
The WallSwitch, coupling relay, and electric valve can be powered from a single power source. When mounting the device, do not allow any moisture to penetrate the WallSwitch, coupling relay or the site of cable connections.
- Connect the power supply source to the power terminals of the WallSwitch observing the polarity.
- Connect the “N” output terminal (neutral) of the WallSwitch to the “N” terminal of the coupling relay, and the “L” terminal (phase) of the WallSwitch — to the “L” contact terminal of the coupling relay.
- Connect the “COM” contact terminal of the coupling relay to the “L” contact terminal of the power source.
- Connect the “NC” contact terminal of the coupling relay to the control opening input of the electric valve, and the “NO” contact terminal — to the closing input.
- Connect the “N” contact terminal (neutral) of the electric valve to the “N” contact terminal of the power source and ground the “PE” contact of the electric valve.
Such connection ensures the closing of the electromagnetic valve using the WallSwitch.
Valve examples:
- Neptun Bugatti Pro 220 V
Operation of the 230 V AC electromagnetic valves featuring two control inputs
No additional WallSwitch set up via the application is required.
Click the switch in the WallSwitch line — the state of the relay contacts will change to the opposite.
When the WallSwitch contacts are closed, the electric valve is supplied with power and it closes. When contacts are opened, the control input is cut off and the electric valve opens.
Electric valve control in the Ajax app
Click the switch in the relay line — the state of the relay contact terminals will change to the opposite.
When the relay contact terminals are closed, the electric valve receives power and opens. When opened, the electric valve remains unpowered and the water is shut off.
Automated control of the electric valve
Create a scenario to activate one or several electric valves automatically when arming/disarming the security system, by alarm or Button press, as well as according to a schedule. The scenario by the alarm of the leak detector creates an automatic anti-flood system that will shut off the water without involving the user.
A scenario can be created in the relay settings: Devices 
→ Relay (or WallSwitch) → Settings 
→ Scenarios.
Learn more: How to create and configure a scenario in the Ajax security system
