It is common for automatic water sprinklers to protect a building from fire. Large vertical water sprinkler pipes rise up from the lowest level of a building to the roof. From this vertical riser smaller horizontal pipes branch off creating overhead canopies protecting each level of a building.
An overhead canopy of water pipes, under pressure, waits to rain on each building level when there is a fire. At the source of each level’s water supply, usually located in the stairwell, is a valve that can shut off the water to sprinklers on that floor.
Closing this valve and interrupting the water supply would create a dangerous situation and leave the floor vulnerable to fire. Due to the severity of this situation it is critical that this valve be monitored 24/7. In the event that someone closes the valve a signal is generated and detected by the fire alarm system.
As electricians it is one of our tasks to make connections between the valve and the fire alarm system.
Presently, on the job I’m working on, the sprinkler fitter is using Victaulic Series 705 Firelock Butterfly valves. These valves have an orange flag indicating if the valve is open or shut. Open means water can flow through the valve and shut means the valve is shut and water can not pass.
The Victaulic valve is equipped with two dry electrical contacts. Contact #1 and Contact #2. These contacts change state when someone turns the valve handle, closing or opening the valve.
Contact #1 has two terminals, the NC terminal has two blue wires terminated on it and the other terminal, the COMMON terminal, has two yellow wires terminated on it. If using a meter there is continuity between the blue and yellow wires when the valve is shut and an open line OL between the blue and yellow wires when the valve is open.
Using a 47K resistor and an FMM-1 monitoring module we can connect the valve to the fire alarm system and monitor the state of the valve.
