Sprinkler Supervision and Monitoring: NFPA 13 and NFPA 72
In most cases, the model fire codes used in the United States require new buildings to monitor sprinkler waterflow in accordance with NFPA 72. The International Fire Code (IFC), Section 903.4, requires valves controlling water supply for automatic sprinkler systems to be supervised by a listed fire alarm control unit. NFPA 1 and 101 contain similar requirements. But what does it mean to be electrically supervised in accordance with NFPA 72?
What does electrically supervised mean?
Electrically supervised means, a listed fire alarm control unit is provided at the protected premises to supervise the water supply valves controlling the automatic sprinkler system. NFPA 72 refers to this as a dedicated function fire alarm system. NFPA 72 added "dedicated function fire alarm system" to the definitions several cycles back to clarify there are conditions when a fire panel is necessary to monitor a specific function (sprinkler control valves, duct detectors, elevator detection, etc.), but a full fire alarm system may not be required. A dedicated function fire alarm system is not required to have notification appliances, common area detection, or pull stations because the system is "dedicated" to a specific function. In this case, monitoring sprinkler waterflow.
NFPA 13 outlines four conditions for supervision of sprinkler control valves in the 2022 Edition of NFPA 13, Section 184.108.40.206.1. The four conditions are:
- Central station, proprietary, or remote station signaling service
- Local signaling service that will cause the sounding of an audible signal at a constantly attended point.
- Valves locked in the correct position
- Valves located within fenced enclosures under the control of the owner, sealed in the open position, and inspected weekly as part of an approved procedure.
IFC Section 102.7.2 takes it a step further where it says, when a referenced standard includes subject matter that is within the scope of this code (IFC), the provisions of the IFC shall take precedence over the provisions in the referenced standard. In this case, IFC section 903.4 requiring a listed fire alarm control unit takes precedence over NFPA 13 (conditions 2, 3 and 4) supervision requirements.
NFPA 13 and NFPA 72
Now that we know sprinkler control valves need to be monitored by a listed fire alarm control unit, what requirements apply to sending the signal from the protected premises to the supervising station? Due to the complexity of this question (and the topic in general), this blog will be broken up into a series, and each article will address different criteria related to monitoring of automatic sprinkler and fire alarm systems. Chapter 26 – Supervising Station Alarm Systems in NFPA 72 addresses how to send the sprinkler waterflow and fire alarm signal to the supervising station.
Single or Multiple Communication Path?
One of the first criteria in determining the method of monitoring is for the owner and contractor to determine if they want a single communication path or a multiple communication path. Both have different requirements in NFPA 72 and there are pros and cons to each. As the term implies, a single communication path refers to one transmission technology. Multiple communication paths use more than one transmission technology to send the signal. Single communication technologies can be less expensive when the owner considers monthly recurring charges. Multiple communication technologies require the owner to pay for two phone lines, which the owner may feel is unnecessary. On the other hand, there are benefits to not "placing all your eggs in one basket" and having a primary and backup transmission means should one be lost.
Are two transmission methods always required for monitoring?
A common misinterpretation is that two transmission paths are always required. This assumption most likely has to do with the fact that for many years digital alarm communicator transmitters (or DACTs) were the default method for monitoring. In its simplest form, DACTs utilize phone lines to transmit the signal to the supervising station and have always been required by NFPA 72 to have two transmission channels. Other monitoring technologies such as cell, radio and internet are approved by NFPA 72 as single communication technologies and are not required to be provided with a backup. In second part of this series, we will discuss the "other" monitoring technologies and explain why NFPA 72 is comfortable with one transmission means for some technologies but not others.
A single communication path is required to be supervised at intervals not exceeding 60 minutes. This means the protected premises must check in with the supervising station a minimum of once per hour. This is referred to as a timer test. A failure to check in with the supervising station a minimum of once every 60 minutes must be annunciated (by trouble signal) at the protected premises.
For multiple communication paths, each path must conduct a timer test at intervals not exceeding 6 hours. Failure to successfully conduct a timer test at least once every 6 hours, must generate a trouble signal. When multiple communication paths are used, a single point of failure in the monitoring network cannot negatively impact the alternative transmission channel. This can be an issue with some monitoring technologies (see diagram below). The red circle in the diagram indicates a single point of failure on the transmission channel. Therefore, this arrangement would not be permitted.
In the next blog, we will discuss approved communication methods, including DACTs, radio, cellular, and internet along with the applicable requirements for each. To be continued…