Potter Releasing Systems - Manual (Page 35)

35
Other Types of Supervision
Low Water Supply Pressure
Loss of water supply pressure in the sprinkler supply mains can be monitored with a supervisory pressure
switch. Care must be taken to adjust the pressure switch below the lowest pressure available during peak
demand periods to avoid nuisance alarms.
Fire Pumps
Fire pumps are automatically started in the event of water flow in a sprinkler system in order to supply more
water pressure to the system. Power to an electric pump should be supervised for loss of phase or phase reversal.
A pump running signal can be obtained by installing a pressure switch in the discharge line of the pump.
Pressure Tanks
These tanks are pressurized waster reservoirs used to supply a limited amount of water for sprinkler systems.
The tanks are usually located above the highest sprinkler heads under the main roof, or in a heated room on the
roof. Each tank is kept 2/3 full of water with a maintained pressure of approximately 75 psi in the tank.
Supervision includes: Water level, low and high pressure, low temperature, and water control valves.
Gravity Water Tanks
Gravity tanks are tower or roof mounted reservoirs and can immediately supply a large volume of water for
sprinkler systems. The tank may have a heating element to prevent freezing.
Supervision includes: Water level, low temperature, and water control valves.
Building Temperature
It is recommended that premises protected by wet sprinkler systems, or the room that a dry pipe valve is
located in, be monitored for low temperature of 40° F. This will prevent sprinkler pipes or dry pipe valves from
freezing should the building heating equipment fail.