Fire pumps are required by NFPA 20 Installation of Stationary Pumps for Fire Protection (2013 edition) to be protected against possible interruption of service through various hazards, including damage due to water infiltration into the fire pump controller. With suction piping, discharge piping, overhead sprinkler protection, etc., located within the fire pump room, these areas are inherently wet locations with multiple direct sources for water that have the potential to harm the fire pump controller in the event of a failure. NFPA 20 includes specific safeguards to address issue of water damage to the fire pump controller(s), including the following:
- Controllers are to be located or protected so that they will not be damaged by water escaping from pumps or pump connections (NFPA 20 §10.2.2)
- All equipment shall be suitable for use in locations subject to a moderate degree of moisture, such as a damp basement (NFPA 20 §10.3.1)
- The fire pump controller enclosure shall be minimally rated for NEMA Type 2, dripproof enclosure(s) or an enclosure with an ingress protection (IP) rating of IP31 (NFPA 20 §10.3.3.1)
Specific requirements for junction boxes located within the fire pump room and serving the fire pump controller (e.g. transition from 2-hour MI cable to standard cable) and raceway terminations into the fire pump controller are also included in NFPA 20 which prohibit the installation of such components in a manner which violates the integrity of the fire pump controller enclosure type rating (i.e. minimum NEMA Type 2). Additional guidance is provided in NEMA Standards Publication ICS 14-2015 Application Guide for Electric Fire Pump Controllers, which recommends all “top-entry conduit fittings into the fire pump controller should be, as a minimum, watertight”; and, side-entry conduit fittings into the fire pump controller “should be suitable for the environment and enclosure type”. These requirements correlate and are generally consistent with Article 695 of NFPA 70 National Electrical Code (2017 edition) for fire pump installations. For NEMA Type 2 controllers, NFPA 70 Table 110.28 considers the enclosure as providing a degree of protection against “falling liquids and light splashing” and notes that such equipment is generally considered “driptight”.
In order to help safeguard fire pump controller from water damage, the City of Boston’s expectation is for all electrical components located within the fire pump room and connected to the fire pump controller to minimally carry the same rating for water ingress as the fire pump controller served (i.e. minimum NEMA Type 2). Where fire pump controller enclosures are listed for a greater level of protection than NEMA Type 2, the higher degree of protection against water infiltration should be extended to the associated and connected junction boxes, conduits and other connections located within the fire pump room. Table 110.28 of NFPA 70 and NEMA ICS 14 can be consulted for additional information, including a comparison of the various types of NEMA enclosures relative to water infiltration requirements.
It should be noted that a wide variety of environmental and installation conditions may exist that will impact the general requirements discussed above. As such, it is important to consult with the Design Team and Authorities Having Jurisdiction during the design phase to ensure that suitable protection methods are being utilized to help safeguard against potential interruption of the fire pump service due to infiltration of water into the fire pump controller. Additional recommendations may also exist due to unique circumstances with the installation, insurance recommendations, and/or manufacturer’s requirements that may exceed the minimum requirements described above.