A fire alarm system is a crucial part of any building, be it commercial or residential. It protects life and property by providing early warning of fire. A fire alarm system comprises of various components, including smoke detectors, heat detectors, fire alarm control panels, and flow switches. The flow switch is an essential component of the fire sprinkler system, and its proper wiring is critical to the system’s proper functioning. In this article, we will discuss the fire alarm flow switch wiring diagram in detail.
What is a Fire Alarm Flow Switch?
A fire alarm flow switch is a monitoring device that senses the flow of water in a fire sprinkler system. It detects the water flowing through the sprinkler system when the sprinklers are activated and sends a signal to the fire alarm control panel. The signal indicates a possible fire situation, and the control panel initiates the alarm to alert the occupants of the building. In simple terms, the flow switch is a crucial component that helps to detect fires and activate the sprinkler system to extinguish them.
Types of Fire Alarm Flow Switches
There are two types of fire alarm flow switches: paddle-type and vane-type.
Paddle-Type Flow Switches
A paddle-type flow switch has a water flow chamber with a hinged paddle. When the water flows in the chamber, the paddle is lifted, and a switch is activated. The switch sends a signal to the fire alarm control panel, indicating that there is water flow in the sprinkler system. These types of flow switches are commonly used in larger pipe sizes.
Vane-Type Flow Switches
A vane-type flow switch has a water flow chamber with a vane placed in the waterway. When the water flows in the chamber, the vane is deflected, and a switch is activated. The switch sends a signal to the fire alarm control panel, indicating that there is water flow in the sprinkler system. These types of flow switches are commonly used in smaller pipe sizes.
Fire Alarm Flow Switch Wiring Diagram
The wiring diagram for a fire alarm flow switch is relatively simple. The flow switch has two sets of contacts that act as a switch. One set of contacts is normally open (NO) and the other set is normally closed (NC). The wiring for the flow switch is connected to the fire alarm control panel in the following manner:
Wiring the NO Contacts:
| Wire Color | Connection Description |
|---|---|
| Red | Connect to the positive terminal of the fire alarm control panel’s power supply. |
| Black | Connect to the NO terminal of the fire alarm control panel’s input circuit. |
| Green | Connect to the ground terminal of the fire alarm control panel. |
Wiring the NC Contacts:
| Wire Color | Connection Description |
|---|---|
| Yellow | Connect to the positive terminal of the fire alarm control panel’s power supply. |
| White | Connect to the NC terminal of the fire alarm control panel’s input circuit. |
| Green | Connect to the ground terminal of the fire alarm control panel. |
The wiring diagram for a fire alarm flow switch is shown in the figure below:
FAQ
What is a flow switch in a fire alarm system?
A flow switch is a monitoring device that senses the flow of water in a fire sprinkler system. It detects the water flowing through the sprinkler system when the sprinklers are activated and sends a signal to the fire alarm control panel. The signal indicates a possible fire situation, and the control panel initiates the alarm to alert the occupants of the building.
What are the types of flow switches used in fire alarm systems?
There are two types of flow switches used in fire alarm systems: paddle-type and vane-type. Paddle-type flow switches have a hinged paddle, while vane-type flow switches have a vane placed in the waterway.
What is the wiring diagram for a fire alarm flow switch?
The wiring diagram for a fire alarm flow switch is relatively simple. The flow switch has two sets of contacts that act as a switch. One set of contacts is normally open (NO) and the other set is normally closed (NC). The wiring for the flow switch is connected to the fire alarm control panel in the following manner: NO contacts are wired to the NO terminal of the input circuit, while NC contacts are wired to the NC terminal of the input circuit.
What is the purpose of a fire alarm flow switch?
The purpose of a fire alarm flow switch is to detect the flow of water in a fire sprinkler system. It sends a signal to the fire alarm control panel when the sprinklers are activated, indicating a possible fire situation. The control panel then initiates the alarm to alert the occupants of the building.
What is the difference between a paddle-type and vane-type flow switch?
A paddle-type flow switch has a hinged paddle, while a vane-type flow switch has a vane placed in the waterway. Paddle-type flow switches are commonly used in larger pipe sizes, while vane-type flow switches are commonly used in smaller pipe sizes.
Conclusion
The proper wiring of a fire alarm flow switch is essential for the proper functioning of a fire sprinkler system. A flow switch detects the flow of water in the sprinkler system, indicating a possible fire situation, and sends a signal to the fire alarm control panel. The wiring diagram for a flow switch is relatively simple and can be easily understood. By following the wiring diagram correctly, you can ensure that your fire sprinkler system functions correctly, providing early warning of fire and protecting life and property.
