The fire pump is a critical element in ensuring the intended performance of liquid-based fire suppression systems, in which the liquid used is predominantly water. Not all suppression systems require fire pumps, but for those that do, operation and performance of the fire pump has to be highly reliable. Where the fire pump motor is electrically powered, the supply circuit and the installed components have to be designed and installed to provide the utmost reliability and to provide resiliency against the effects of a fire within the protected building or structure. Article 695 provides installation requirements for electric fire pump motors, but the NEC® is not the only code or standard covering this important fire protection equipment. NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection, contains a number of requirements that directly affect the electrical installation of a fire pump.

History of Electric Fire Pump Requirements

Article 695 is relatively new with respect to the over 100-year history of the NEC. The first NEC article on fire pumps appeared in the 1996 edition. However, requirements for electrically powered fire pumps have been in place since 1904. Prior to 1996, the requirements for power supply and performance of the electrical installation were located exclusively in the standard covering fire pumps, known to the industry as NFPA 20. General requirements for wiring methods and other items related to installation were always under the purview of the NEC; however, an NEC-compliant installation did not necessarily guarantee compliance with NFPA 20. For example, an installation that followed all of the applicable NEC requirements for a motor installation, including the wiring method and physical routing of the conductors from the service to the fire pump, may have been deficient relative to the reliability requirements of NFPA 20. Running the circuit through the building exposed the pump wiring to the effect of a fire within the building. NFPA 20 covered the performance of the electrical circuit and prohibited routing the wiring method through the building without some type of protection against fire. The fact that NFPA 20 requirements indirectly impacted the physical installation of the electrical equipment and circuit was the major impetus for Article 695 to be included in the NEC.   

The first standard on electrically driven fire pumps was issued in 1904 by the National Board of Fire Underwriters (NBFU). That first standard, NBFU 20A, entitled Rules and Requirements of the National Board of Fire Underwriters for the Construction and Installation of Electric Fire Pumps as Recommended by the National Fire Protection Association, standardized requirements for electric supply, for the operational and performance characteristics of control components, and for the construction of the fire pump. In 1914, NBFU 20A was combined with two other standards covering fire pumps, NBFU 20B and NBFU 20E, to form the first edition of NBFU 20, which had a document date of 1915. The original standard on electric fire pumps, NBFU 20A, was redesignated NFPA 20A in 1907.

NBFU 20 was officially redesignated NFPA 20 when it was revised for the 1951 edition. From that point on, NFPA was responsible for the development and revision of the standard. NFPA 20 has been revised on a regular basis and currently is revised every three years.

In reviewing some of the requirements in the very first standard on electric fire pumps, it is clear that the reliability of the equipment is of paramount importance. In the 1904 edition, the following requirements covering the current (power) supply are found:

Current Supply.

Whether any particular current supply will be satisfactory must be left more or less to the discretion of the Underwriters having jurisdiction, but any source should within reasonable limits meet the following requirements:

a. The current should be “furnished from a fireproof or semi-fireproof constructed station.”

NOTE: A station having brick walls, concrete floors, plank roof, and containing modern apparatus and equipment, will be considered as a "semi-fireproof" station. It is desirable to have the mains and feeders supplied by two or more stations, any one of which is capable of furnishing the necessary current. When two stations are available, good non-fireproof stations may be accepted in place of fireproof but fireproof stations should be chosen whenever possible.

b. The supply of current must be from mains and feeders which can furnish the necessary current at all times, day or night, every day in the year, and which can show a service record of no interruption in any one year, exceeding one-half hour, and not over four interruptions exceeding five minutes each.

c. The supply must have a reserve capacity such as to be in no way discommoded provided the maximum quantity needed, by a reasonable number of motors supplied, was suddenly called for in addition to the normal load of the circuit.

In addition to the requirements on the power supply characteristics, the original standard contained requirements to limit the voltage drop on the fire pump circuit and to provide only short-circuit protection for the main and feeder conductors.

Although the requirements contained in the 2008 NEC and the 2007 edition of NFPA 20 are not worded exactly the same as were the provisions contained in the 1904 edition of NBFU 20A, the objective to provide a highly reliable power source was clearly the same then as it is today. As building construction technology and wiring systems evolve, the methods by which this objective can be met continually improves each time the NEC or NFPA 20 is revised.

Committee Scopes – Two Different Responsibilities

Code-Making Panel 13 of the National Electrical Code Committee and the Technical Committee on Fire Pumps have different responsibilities in respect to the fire pump electrical system. These different responsibilities were clearly defined by the NFPA Standards Council based on the overall scope of these two committees. Simply put, NFPA 20 contains requirements covering the performance of the fire pump electrical installation, and Article 695 of NFPA 70 is responsible for requirements covering the installation of the electrical equipment. In order to achieve compliance with the system performance required by NFPA 20, installations meeting Article 695 are required.

Extracted Requirements

So that an electrical contractor does not have to rely on two documents, there are provisions within Article 695 that are extracted from the 2007 edition of NFPA 20. Examples of extracted requirements are 695.3(A)(1), (A)(2), (B)(1), and (B)(2). These sections cover acceptable power supply arrangements and their effect on the mechanical execution of the electrical installation, but the overall objective of these sections is the reliability of the power supply to the fire pump. Therefore, the bases for these NEC requirements are found in the requirements of Chapter 9 of NFPA 20 and are the responsibility of that document's technical committee.

Performance Objectives Create the Need for Installation Requirements

Requirements such as conductor sizing and wiring methods contained in 695.6(A) through (E) are installation requirements and as such are the responsibility of the National Electrical Code Committee. Although one could say these requirements relate to the performance of the fire pump, if performance and installation are viewed as a larger picture, we can see that the performance objective of NFPA 20 is to have a reliable circuit to the fire pump. The NEC provides specific requirements on how the wiring can be installed in order to achieve the desired level of performance.

The Desired Result

As the requirements in NFPA 20 and NEC Article 695 are applied to a fire pump installation, the desired result is to provide a power source, a supply circuit, and fire pump equipment such as controllers, transfer switches, and motors that are reliable and that also meet the NEC objectives of not being a fire or shock hazard. Both the committee for NFPA 20 and the committees for the NEC operate within their respective scopes, and both documents provide requirements that result in a highly reliable, electrically safe fire pump installation.

Jeffrey S. Sargent is Senior Electrical Specialist at NFPA. He serves as staff liaison
to several NFPA technical committees and is the executive secretary to the NFPA Electrical Section.
Prior to joining NFPA in 1997, he served as an electrical inspector in state and municipal positions
and as an electrical program instructor. Sargent is a licensed master electrician,
a certified electrical inspector, and a member of IAEI.