AUTHOR: Shawn Mahoney

Standpipe System Design and Calculations

Standpipe systems consist of piping and hose connections installed throughout a building to provide reliable water for the manual suppression of a fire by either the fire department or trained personnel. NFPA 14, Standard for the Installation of Standpipe and Hose Systems, Chapter 6, outlines design and installation requirements for standpipe and hose systems. Standpipe systems can be broken down into different types of systems to delineate whether the piping is full of water (wet) or not (dry) and whether the water supplied for firefighting is automatically provided by a water supply, such as a city main or a tank and fire pump (automatic or semi-automatic), or needs to be provided by a fire department pumper (manual). When designing a system, you first need to determine the supply pipe size, hose connection location, size, and pressure based on the standpipe classification. There are three classes of standpipe systems, they include Class I, Class II, and Class II. Class I Class I systems are installed for use by the fire department and are typically required in buildings that have more than three stories above or below grade because of the time and difficulty involved in laying hose from fire apparatus directly to remote floors. Class I systems are also sometimes required in malls, because these occupancies contain areas that are difficult to access directly with hose from fire apparatus. Locations for hose connections in Class I systems include: Each main floor landing or intermediate landing of required stairs. On the roof if the stairwell does not have access to the roof. Each side of exit openings in horizontal exits. Exit passageways. Additional hose connections should be available in unsprinklered buildings where the distance from a hose connection to the most remote part of the floor exceeds the limits in NFPA 14 based on the sprinkler system type and building type. The minimum residual pressure required for a Class I system is 100 psi (6.9 bar) from the hydraulically most  remote 2 ½ in. (65 mm) hose connection with a flow rate of 500 gpm (1893 L/min), through the two most remote 2 ½  in. (65 mm) hose connections. A pressure-regulating device may need to be used in order to limit the pressure at hose connections to less 175 psi (12.1 bar) static (pressure when not flowing).            Class II Class II are installed for use by trained personnel and are often required in large un-sprinklered buildings. They might also be required to protect special hazard areas, such as exhibit halls and stages. In the past, Class II standpipes were typically installed with a hose, nozzle, and hose rack on each hose connection. Prior to the 2007 edition of NFPA 14, Class II systems were defined as being for use “primarily by the building occupants or by the fire department.” Because of concerns regarding the ability of untrained occupants to safely use the hose and the encouragement of occupants to fight the fire rather than evacuate, the Technical Committee chose to define Class II systems as being for use by “trained personnel or by the fire department.” Class II systems need to provide enough hose stations so that all portions of each floor level of the building are within 130 ft (39.7 m) of a 1 ½ in. (40 mm) hose connection provided with 1 1∕ 2 in. (40 mm) hose or within 120 ft (36.6 m) of a hose connection provided with less than 1 1½ ∕ 2 in. (40 mm) hose connection. The minimum residual pressure required for a Class II system is 65 psi (4.5 bar) from a remote 1 -1/2½ in. (40 mm) hose connection with a minimum flow rate of 100 gpm (379 L/min). A pressure-regulating device may need to be used in order to limit the pressure at these hose connections to less than 100 psi (6.9 bar) residual (pressure when flowing) and 175 psi (12.1 bar) static (pressure when not flowing). Class III Class III systems combine the features of Class I and Class II systems. They are provided for both full-scale and first-aid firefighting. These systems are generally intended for use by fire departments and fire brigades. Because of their multiple uses, Class III systems are provided with both Class I and Class II hose connections and must meet the placement, pressure, and flow requirements for both Class I and Class II systems. Pipe sizing The minimum size pipe for Class I and III standpipes is 4 in. (100 mm). If the standpipe is part of a combined sprinkler system in a partially sprinklered building, that is increased to 6 inches (150 mm). If the building is protected with an automatic sprinkler system, then the minimum combined standpipe size can be 4 in. (100 mm) if hydraulically calculated. The branch lines of the standpipe system are to be sized hydraulically but cannot be smaller than 2 -1/2½ in. (65 mm). Calculating Hydraulically calculating a standpipe system is very similar to that of a sprinkler system because we are calculating the pressure lost in the system to get the required flow to the most remote hose connection. In addition to the required flow from the most remote hose connections, based on the classification we are required to also calculate flow from connections on each standpipe. For example, when calculating a Class 1 Standpipe system in a building that is less than 80,000 ft2 (7432m2) we need to calculate the flow rate of 500 gpm (1893 L/min), through the two most remote 2 ½  in. (65 mm) hose connections at 100 psi (6.9 bar) and also calculate an additional 250 gpm (946 lpm) flowing from each standpipe in the building up to a maximum total flowrate of 1000 gpm (3785 L/⁠min) for buildings that sprinklered throughout, and 1250 gpm (4731 L/min) for buildings that are not sprinklered throughout. Take a look at this video taken from our soon to be released Online Certified Water-Based System Professional Learning Path discussing how to hydraulically calculate a standpipe system. Want to Learn More? Keep an eye out for our Certified Water-Based Systems Professional Learning Path. Also, If you found this article helpful, subscribe to the NFPA Network Newsletter for monthly, personalized content related to the world of fire, electrical, and building & life safety.

Importance of Inspection Testing and Maintenance of Fire Protection Systems

Sprinkler systems are exceptionally reliable, such that the chance of dying in a fire is reduced by one-half to three-fourths when sprinklers are installed in a building. Statistics also show that property damage is reduced by half to two-thirds when sprinklers are present. All of this is true, of course, only if the system has been designed, installed, and maintained properly. It has been seen that in 59% of incidents in which sprinklers failed to operate, the system had been shut off. This is a reason why the Inspection, Testing, and Maintenance (ITM) of water-based fire protection systems is so crucial. NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems is the baseline for inspection, testing, and maintenance of water-based fire protection systems. The purpose of NFPA 25 is to provide requirements that ensure a reasonable degree of protection for life and property from fire through minimum inspection, testing, and maintenance methods for water-based fire protection systems. Care and maintenance include more than the inspection and testing of system components. For effective protection, an evaluation of the factors that affect system performance should be made. These factors include such items as the following: Occupancy changes Process or material changes Building modifications such as relocated partitions or ceilings or the addition of mezzanines Modifications to the heating system exposing systems to potential freezing To maintain the proper level of protection for a water-based extinguishing system, there are four areas of concern: Adherence to a regular inspection schedule as determined by the needs of the system Execution of any special investigations or tests that can assess the performance of the devices and equipment Exercise of due diligence in the repair of devices and equipment Assurance that all personnel involved in maintenance are properly trained to correctly execute the procedures for inspection, testing, and maintenance of equipment There are many new technologies and advancements in the field of fire protection system ITM that are being utilized to ensure that these systems remain operational. Automated inspection and testing Automated inspection and testing is being utilized more often with advancements in technology. The overall concept behind these inspections and testing methods is that they mimic the formerly manual process and produce the same outcome. For example, a sensor on a fire pump housing that records the temperature during testing can replicate the same outcome as a person measuring the temperature manually. However, some inspections and tests require the presence of a qualified person and cannot be performed automatically. Data analysis The increased use of data collection and analysis that can be completed on fire protection systems is being used to determine if there can be a change in the required inspection, test, and maintenance frequencies as well as determining if the monitoring of such equipment in real time can be used to detect an upcoming failure of the system.

Guide to Fire Alarm Basics – Power Supplies

A fire alarm system is a crucial part of the overall fire protection and life safety strategy of a building. A fire alarm system serves many functions and the differences between the functions can be a bit confusing, so I created a visual guide to fire alarm basics. The objective of this blog series is to discuss some of the major components and functions of a fire alarm system. For an overview of the entire system take a look at my Guide to Fire Alarm Basics Blog. This blog will take a deeper dive into fire alarm power supplies. It is important for a fire alarm system to be provided with reliable power so it can operate during any emergency. There are a few different options when it comes to choosing a reliable power supply, as well as some calculations that are necessary to ensure that the fire alarm system is provided with sufficient backup power.    There are a few different options out there when it comes to providing a reliable power source. They include providing an additional power source in addition to the primary power such as batteries or an emergency generator so there is backup power if primary power is lost or providing power through a single source such as a Stored-Energy Emergency Power Supply System (SEPSS). Primary power to the fire alarm system can be provided by the electric utility, an engine-driven generator (this is not a standby generator, however it is a site generator meeting the requirements in NFPA 72), and Stored-Energy Emergency Power Supply System (SEPSS), or a cogeneration system. Batteries are a common way to provide a secondary power supply, the most common type of battery is a Valve-Regulated Lead-Acid battery and they are typically located within the fire alarm control unit enclosure, or in a separate battery box located near the fire alarm control unit. Batteries need to be sized so that they can provide power to the entire fire alarm system for 24 hours in standby and 5 minutes in alarm, if the system is an emergency voice alarm communication system (EVACS), then the batteries need to provide capacity for 15 minutes in alarm in addition to the 24 hours in standby. The additional time is required to allow for a longer evacuation time as buildings with an EVACS typically utilize a partial evacuation that would require constant communication with the occupants during the evacuation. Another common way of providing a secondary power supply for a fire alarm system is the use of an emergency generator designed, installed, and maintained in accordance with NFPA 110, Standard for Emergency and Standby Power Systems, which provides power to the fire alarm system through an automatic transfer switch. If using an emergency generator, you are still required to provide batteries as well just in case there is an issue with getting the emergency generator started. These batteries however, only need to provide a capacity for 4 hours instead of the 24 hours in standby. Instead of providing two separate power supplies, you are permitted to provide power via a Stored-Energy Emergency Power Supply System (SEPSS) otherwise known as an Energy Storage System (ESS) or an Uninterruptible Power Supply (UPS).  The SEPSS must be configured in accordance with NFPA 111 and provide 24 hours of backup battery. The SEPSS is also fed via a compliant primary power supply such as utility power or an on site generator. As noted above, if batteries are part of the secondary power source for a fire alarm system then they must be sized to provide capacity to run the system for 24 hours in standby and then either 5 minutes in alarm or 15 minutes in alarm for EVACS. A simple calculation for a basic fire alarm can be seen above. 1) First the total system standby current and the total system alarm current is calculated. This is done by multiplying the standby current and alarm current for each piece of equipment by the total quantity of each piece of equipment and adding them together, the result is the total AMPS required in standby and alarm. Both the standby current and the alarm current for equipment can be found from the manufacturer in the data sheet. 2) Next total standby capacity is required by multiplying the total system standby current by the required 24 hours to achieve the required standby capacity in AMP-HRS. The same is done with the alarm capacity, however, instead of 24 hours, the current is multiplied by either 5 minutes (0.083 hours) or 15 minutes (.25 hours) to achieve the required alarm capacity in AMP-HRS. 3) Finally, both the standby capacity and the alarm capacity is added together and a 25% safety factor is applied to arrive at the total required battery capacity. Want to Learn More? Like I noted in the beginning of this blog, if you are interested in learning more about fire alarm basics, take a look at my Fire Alarm Basics Blog. If you found this article helpful, subscribe to the NFPA Network Newsletter for monthly, personalized content related to the world of fire, electrical, and building & life safety.

A Guide to Fire Alarm Basics – Off-Premises Signaling and Supervising Stations

A fire alarm system is a crucial part of the overall fire protection and life safety strategy of a building. A fire alarm system serves many functions and the differences between the functions can be a bit confusing, so I created a visual guide to fire alarm basics. The objective of this blog series is to discuss some of the major components and functions of a fire alarm system. For an overview of the entire system take a look at my Guide to Fire Alarm Basics Blog. This blog will take a deeper dive into fire alarm system off-premises signaling and supervising stations. When talking about fire alarm systems, the term premises includes the entire area monitored by the fire alarm, this could include the entire building or even an entire campus. Off premises signaling is important because it allows signals from the fire alarm system to be sent to a constantly attended location (supervising station or a public communication center) to ensure the proper response. The purpose of off-premises signaling is to provide dedicated, 24-hour monitoring for a fire alarm and signaling system and to initiate the appropriate response to those signals. In the case of a fire alarm condition (fire detected in the building), the appropriate response usually includes the dispatching of the local fire department or fire brigade. In the case of a supervisory condition, such as a closed sprinkler valve, the appropriate response might be the notification of designated maintenance personnel or outside contractors.   If a fire alarm and signaling system is sending signals off premises, it is either (1) sending signals through a Public Emergency Alarm Reporting System, or (2) the fire alarm system is part of a Supervising Station Alarm System. Regardless of the system, in today’s world they all consist of a type of transmitter at the protected premises that uses a transmission and/or communications channel and pathway to send signals to a receiver at the supervising station or public communications center.     A Public Emergency Alarm Reporting System (PEARS), otherwise known as a Municipal Emergency (Fire) Alarm System is a communication infrastructure, other than a public telephone network that is used to communicate with a communication center. Typically, this communication infrastructure is owned, operated, and controlled by a public agency. The system itself does not include the fire alarm control unit or any of the equipment that is located on the protected premise, instead, it starts at the transmitter and ends at the public communication center.   One way the interface between the fire alarm control unit and the PEARS is completed is using a master fire alarm box, which is an addressable manual pull station on the PEARS system that has an interface circuit that allows a fire alarm control unit to actuate the master box when the system initiates a fire alarm signal. Large municipalities usually locate the communications center at a facility designed for the purpose. Small communities often locate the communications center at the fire station, police station, sheriff’s office, or a private agency that has been contracted to provide public emergency communications services. NFPA 1221, Standard for the Installation, Maintenance, and Use of Emergency Services Communications Systems, provides requirements for the installation, performance, operation, and maintenance of communications systems and facilities.     If off-premises signaling is provided by a private company, it is most likely completed using a supervising station alarm system.  A supervising station alarm system consists of everything connected to the supervising station, including the protected premises fire alarm control unit and devices.   Supervising Station Alarm Systems are further divided into three specific types. They are Central Station Service Alarm Systems Proprietary Supervising Station Alarm Systems Remote Supervising Station Alarm Systems.     A Central Station Service Alarm system consists of a remotely located supervising station that is listed for central station service to UL 827 Central-Station Alarm Services and, in addition to monitoring, it provides several other services including record keeping and reporting, testing services, and runner service. This can either be required by code or some insurance companies for certain occupancies. This option can also be chosen by a building owner who wants to have a single contract with a provider who supplies monitoring as well as inspection, testing, and maintenance and other services required of central stations.     A Proprietary Supervising Station Alarm System consists of a supervising station under the same ownership as the protected building that it supervises. These can be useful to owners who have very large buildings or a campus or for owners who have numerous buildings in many locations and who are able to dedicate the space and staffing levels to accomplish this. Proprietary supervising stations can be located on the same premises as the fire alarm system or at another location; these are most often used by large airports, industrial plants, college campuses, large hospitals, and retail chains, among other facilities. An example of this is a big box store that has a dedicated location that monitors all of its store locations. Additional fire alarm services including record keeping, equipment installation, inspection, testing, and maintenance are the responsibility of the owner and can be accomplished in-house or be contracted out to an outside contractor.   A Remote Supervising Station Alarm Systems consists of a constantly attended location that receives signals from various protected premises typically owned by different parties. Unlike central station fire alarm systems, contracts for this service are typically limited to the monitoring and recording of signals from the fire alarm system. Additional services including equipment installation, inspection, testing, and maintenance are the responsibility of the owner. This is an option for owners who are not required or do not want to provide central service and for whom a proprietary supervising station does not make sense. It also may be common for a municipality to operate a remote supervising station as a way to receive signals at their communication center if they are not utilizing a public emergency alarm reporting system.  There are many different methods that can be used for the fire alarm control unit to communicate to the supervising station, and NFPA 72 outlines the requirements for four different types that are permitted in new installations, which includes both wired and wireless methods. Want to learn more? Like I noted in the beginning of this blog, if you are interested in learning more about fire alarm basics, take a look at my Fire Alarm Basics Blog. I will be updating this series over the next few months to add a deeper dive into different portions of the fire alarm system. If you found this article helpful, subscribe to the NFPA Network Newsletter for monthly, personalized content related to the world of fire, electrical, and building & life safety.

A Guide to Fire Alarm Basics – Emergency Control Functions

A fire alarm system is a crucial part of the overall fire protection and life safety strategy of a building. A fire alarm system serves many functions and the differences between the functions can be a bit confusing, so I created a visual guide to fire alarm basics. The objective of this blog series is to discuss some of the major components and functions of a fire alarm system. For an overview of the entire system take a look at my Guide to Fire Alarm Basics blog. This blog will take a deeper dive into the emergency controls of a fire alarm system.     The fire alarm control unit can be used to control the function of other systems such as elevator recall, automatic door closers, smoke control systems, and so on. The most common way that the fire alarm can do this is through the use of a control circuit and a relay.     A control circuit is essentially a notification appliance circuit (NAC) that is used to send power to a relay instead of notification appliances. A relay is a switch that is open and closed electromechanically and allows the fire alarm control unit to operate emergency control functions. As seen above, power sent from the fire alarm control unit will energize an electro-magnet coil, which will cause the switch, which is controlling power coming into the common terminal (C) to move from the normally closed (NC) position to the normally open (NO) position. This switch can then be used to control other systems.   The control outputs from a fire alarm control unit can also be sent out on a signaling line circuit (SLC) to an addressable output module, which can open or close a contact based on information sent from the fire alarm control unit on the SLC to the COMM terminals. This is beneficial because multiple output modules can be controlled by the same SLC, which can control each module separately. For example, all output modules controlling all of the door hold opens in a building could be on the same SLC, but based on the specific input to the control unit, only specific doors can be closed. If all of these modules were on the same control circuit, the control unit would only be able to close all the doors.      The fire alarm control unit can also be used to send a signal to the elevator controller to initiate elevator recall or shutdown. The fire alarm control unit will send a signal to send the elevator to the designated level (typically street level) when a smoke detector on any floor lobby or in the elevator machine room detects smoke, if smoke is detected in the designated level lobby the elevator will be sent to the alternate level (typically the level above the designated level). This is done to protect any of the occupants in the elevator by ensuring that they exit the building and do not go to a floor that has a fire on it.   If the elevator hoist way, pit, or machine room is required to have sprinklers, the fire alarm control unit is used to cut power to the elevator via a shunt trip prior to sprinkler activation to protect occupants. This is done by either placing a heat detector with a lower response time index (RTI) next to the sprinkler or by using a waterflow switch next to the sprinkler. The lower RTI means the heat detector would activate before the sprinkler, if a waterflow switch is used, it would need to have a 0 second time delay.     Many building designs include the use of large open spaces such as atriums that connect multiple floors of a building. To keep occupants safe in the event of a fire, a smoke control system may be needed to maintain the level of smoke above the occupants as they are exiting the building. These systems may be composed of exhaust fans and makeup air openings that are all controlled by a separate smoke control panel. The fire alarm control unit is responsible for sending a signal to the smoke control panel to initiate smoke removal when specific smoke detectors, pull stations, and waterflow alarms within the protected space are actuated. Additionally, the fire alarm control unit may be responsible for closing specific fire doors and dampers to enclose the smoke control zone. Want to learn more about smoke control systems? Check out this blog.    If a fire were to start within a building, an important objective is to contain the fire and products of combustion within an enclosed space for as long as possible. This is accomplished through construction that can resist the passage of fire. In most buildings these fire-resistant barriers can be found in corridor walls, and shafts (including stairwells). Openings within the fire-resistant construction need to be protected with fire doors. For these doors to be effective they need to be closed, so they are equipped with automatic closers. In some cases, the fire alarm can be used to hold these doors open with an electro-magnet door holder. Upon alarm, the fire alarm control unit will send a signal to cut power to the electro-magnets allowing the door to close.    A key piece of documentation for the fire alarm system is known as the input/output matrix. This table outlines all the outputs from the fire alarm control unit when a given input is received. Above is a portion of the input/output matrix outlining elevator recall. An example shown on this chart would be when the fire alarm control unit receives an input from the 1st floor elevator lobby smoke detector (row 6) it will activate the NAC circuit 1 and NAC circuit 2 as well as send a signal to the elevator controller to recall the elevator to the alternate level. This document is key to the proper design of a fire alarm system and is also a crucial when performing testing to ensure that all of these systems are working as intended. When a fire alarm control unit controls another system, it is known as system integration. It is crucial that the fire alarm system along with all integrated systems are tested properly. For more information on integrated fire protection and life safety system testing take a look at this fact sheet on NFPA 4. Go here for an interactive learning module on integrated system testing. Want to learn more? Like I noted in the beginning of this blog, if you are interested in learning more about fire alarm basics, take a look at my Fire Alarm Basics blog. I will be updating this series over the next few months to add a deeper dive into different portions of the fire alarm system. If you found this article helpful, subscribe to the NFPA Network Newsletter for monthly, personalized content related to the world of fire, electrical, and building & life safety.

A Guide to Fire Alarm Basics - Supervision

A fire alarm system is a crucial part of the overall fire protection and life safety strategy of a building . A fire alarm system serves many functions and the differences between the functions can be a bit confusing, so I created a visual guide to fire alarm basics. The objective of this blog series is to discuss some of the major components and functions of a fire alarm system. For an overview of the entire system take a look at my Guide to Fire Alarm Basics Blog. This blog will take a deeper dive into the supervision portion of a fire alarm system.   It is common and often required to utilize a fire alarm system to monitor the condition of other systems, processes, or equipment that are related to the building’s fire and life safety or other systems that the owner would like to monitor. Supervision can include but is not limited to valves on fire protection systems, other fire protection systems such as kitchen hood suppression systems, valve room or storage tank temperatures, and fire pump condition. Issues with these systems would provide a signal to the fire alarm control unit via an initiating device circuit (IDC) for conventional systems, or a signaling line circuit (SLC) for addressable systems and would create a supervisory condition at the fire alarm control unit (FACU).   Conventional supervisory devices are devices that are used on an initiating device circuit and use a switch contact to short both sides of the device circuit together. By doing so, the device causes an increase in current flowing through the circuit, which the FACU interprets as a supervisory signal. Once one device shorts the circuit, no other device on that circuit or “zone” can send a signal. Because of this, any device on the circuit or “zone” will put the entire zone into a supervisory state. Zones are typically designed to enable someone to easily identify an area where the supervisory is located, for example, you may have all of the valve supervisory switches for one system on its own zone so the supervisory comes up as “supervisory wet pipe system 1”.     Addressable supervisory devices are capable of communicating a unique identification number or address to a control unit via a signaling line circuit. This identification consists of a binary string of 1s and 0s that indicate the address or location of that device on the circuit. When the FACU polls a supervisory device, the device responds with its status (Normal, supervisory, etc.) and address. The device address allows for the location to be identified at the FACU. When one supervisory device is activated on a signaling line circuit, the FACU is still able to poll the other devices unlike a conventional initiating device circuit. Additionally, some addressable supervisory devices are also able to transmit to the FACU a range of values such as temperature, water level, pressure, and other variables, and then the control unit software determines the set points for initiation of a supervisory signal. These types of supervisory devices are known as analog addressable as they are able to tell the FACU their address and their value.   Valves that can shut off the water supply for a fire suppression system such as a sprinkler system are required to be supervised to ensure that they are not closed while the system is in service. One way of supervising these valves is the use of the fire alarm system. This is done by installing a switch, which will send distinct signals to indicate that either a control valve has been moved from its normal position (typically meaning that the valve has been shut) or that the control valve has been restored back to its normal position.     Water-based fire suppression systems are required to be maintained above a temperature of 40O F (4O C) where the system piping is filled with water. One way to ensure that these systems are not subject to freezing temperatures is to utilize the fire alarm system. This is done by placing temperature devices that can send a signal to the fire alarm control unit when the temperature in a space has dropped below 40O F (4O C) and for when the temperature has been restored to a temperature above 40O F (4O C). If a building has a fire suppression system other than a sprinkler system such as a kitchen hood suppression system, or an inert gas system, it may be required to be monitored by athe fire alarm system. Based on the system type and the building occupancy, some of the signals may appear on the fire alarm control unit as a supervisory signal, which indicates that either the system has actuated or there is an issue with the suppression system that must be addressed. The other suppression systems may be connected directly to the building fire alarm control unit, or the other suppression system is controlled by its own fire alarm control unit (known as a releasing panel) that is then connected to the buildings main fire alarm control unit. Some water-based fire suppression systems such as a dry pipe or pre-action sprinkler system may require the use of pressurized air or nitrogen within the system piping. In some cases, the pressure within the piping is required to be supervised by the fire alarm system. This is done using pressure transducers or pressure switches that are connected to the fire alarm control unit. A supervisory condition may then be created if the pressure in the piping is too high, or too low.         If the building has a fire pump that supplies a water-based fire suppression system such as a sprinkler system or a standpipe system, the fire alarm control unit is connected to the fire pump controller to monitor for the following conditions: Pump or engine running Controller main switch off normal Trouble with the controller or engine Main power to electric fire pump disconnected Phase reversal on electric fire pump Loss of phase on electric fire pump For more information on fire pumps take a look at this blog.   If a water tank is used to supply a water-based fire suppression system, the water level in the tank and the temperature of the water may need to be monitored. This is done by installing water level sensors within the tank that can send a signal if the water level drops by a specified level, and the installation of water temperature sensors that can send signals if the temperature drops below 40O F (4O C) and for when the temperature has been restored to a temperature above 40O F (4O C). Want to Learn More? Like I noted in the beginning of this blog, if you are interested in learning more about fire alarm basics, take a look at my Fire Alarm Basics Blog. I will be updating this series over the next few months to add a deeper dive into different portions of the fire alarm system. If you found this article helpful, subscribe to the NFPA Network Newsletter for monthly, personalized content related to the world of fire, electrical, and building & life safety.
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