The CE Code, Part I governs installation of various electrical equipment. A fire pump is certainly also covered by the Code requirements. But in addition to the CEC, Part I, this type of electrical equipment must meet provisions of other important documents.
Let’s check out these additional requirements. Our first stop is the scope of Section 32-000(1). It states, "This section applies to the installation of fire pumps required by the National Building Code of Canada.” This means that unique requirements of Rules 32-200 – 32-212 do not have to apply for a pump installed in a water system, if this pump is not considered to be a "”required fire pump”" by the NBC of Canada. This observation leads us to the second stop—NBCC.
Article 126.96.36.199 of the NBCC appears to be sufficiently clear in its intent. It states, "An adequate water supply for fire fighting shall be provided for every building.” This is a well understood objective, but how does it correlate with a requirement for a fire pump? The answer may be found in A-3 of Appendix A to the NBCC.
Explanatory notes in A-3 on "”Fire Fighting Assumptions”" provide comprehensive clarification regarding the water supply requirements for fire protection installations. These notes indicate that acceptable water supplies may be furnished by various means, and that use of automatic fire pumps is one of such means.
Further, Article 188.8.131.52 of the NBCC states the following: "”If a fire pump is installed, it shall be installed in accordance with the requirements of NFPA 20, Standard for the Installation of Centrifugal Fire Pumps.”"
Appendix A Note on this NBCC article explains that the Building Code provision to ensure an adequate water supply may be met by installing "a fire pump for a building that has either a standpipe system or an automatic sprinkler system installed.”
What does it mean for us, electrical practitioners? It simply means that a professional electrical engineer responsible for the design of the project must clearly understand whether an adequate water supply for fire fighting in the building is, in fact, dependent on an automatic fire pump? And if the answer is: "”Yes,”" then requirements of NFPA 20 and respective rules in Section 32 of the CEC, Part I must apply.
Let’s say that a fire pump is required to provide an adequate water supply mandated by the NBCC.
Thus, we’re ready for the third stop—at NFPA 20. This standard provides elaborate criteria for installation of fire pumps and their auxiliary equipment. It mandates normal and alternate power supply sources, protection of feeder conductors against exposure to fire, selection of disconnecting means and over-current protection devices upstream from a fire pump controller and characteristics of the fire pump controller including alarm and signal devices on controller.
NFPA 20 also states that when the pump room is not constantly attended, the following audible and visible signals have to be provided at a point of constant attendance:
a. Pump or motor running
b. Loss of phase
c. Phase reversal
d. Controller connected to alternate source
Note: This point of constant attendance should be a fire alarm annunciator of the building fire alarm system. [Sentence 184.108.40.206. (2) of the NBCC requires electrical supervision of a fire pump].
These supervisory conditions are verified by the fire protection and electrical experts during commissioning of a fire pump at the installation site.
As we know, many requirements of NFPA 20 have been already incorporated in Rule 32-206 of the CEC. These requirements include a need for a separate automatic transfer switch for each fire pump and a special certification of this transfer switch for "fire pump service.”
However, many other requirements of the NFPA 20 have only recently been adopted by the CEC, Part I Committee for inclusion into the 20th edition of the Code. These requirements will be mandating protection of conductors against exposure to fire, coordination of selected upstream O/C protection for a fire pump circuit with the O/C protection provided in the fire pump controller, when a fire pump is supplied from a normal power, and selection of the O/C protection for a fire pump feeder when the fire pump is supplied from an emergency generator. (The NBCC requires an emergency generator as a source of alternate power supply for an electrically connected fire pump).
Thus, we are now ready for our final, fourth stop (which brings us back to a portion of Section 32 that is dedicated to fire pumps.)
Exact wiring of new fire pump requirements in the 20th edition of the CEC is shown below (text in a different typeface depicts new wording in the 20th edition of the CEC, Part I.)
Rule 32-200 has been modified to read:
"32-200 Conductors (see Appendix B)
Conductors from the emergency power source to a fire pump shall :
(a) Have ampacity not less than:
(i) 125% of the full load current rating of the motor, where an individual motor is provided with the fire pump; and
(ii) 125% of the sum of the full load currents of the fire pump, jockey pump, and the fire pump auxiliary loads, where two or more motors are provided with the fire pump; and
(b) Be protected against fire exposure to provide continued operation in compliance with the National Building Code of Canada”"
Appendix B Note on Rule 32-200:
"Intent of this rule is to protect the feeder conductors between a fire pump and an emergency power source from fire damage.
The National Building Code of Canada requires that conductors supplying a life and fire safety equipment be protected against exposure to fire to ensure continued operation of this equipment for a period not less than 1 h.
NFPA 20 also mandates protection of circuits feeding fire pumps against possible damage by fire.
The following example illustrates acceptable methods for achieving this protection:
a) Using mineral insulated cables conforming to fire rating requirements as specified in Clause 5.3 of the CSA Standard C22.2 No. 124 "”Mineral Insulated Cable”";
b) Embedding the raceway containing fire pump feeder conductors in not less than 50 mm of concrete;
c) Installing the raceway containing fire pump feeder conductors in a shaft enclosure or service space of at least 1hour fire resistance construction.
Specific requirements pertaining to the fire resistance rating of a material or an assembly of materials can be found in subsection 3.1.7 of the National Building Code of Canada or in the appropriate Provincial/Territorial Legislation.”"
Rule 32-204 has been amended by deleting Subrule (3) and by adding the following wording to Subrule (1):
32-204(1) "”A separate service box conforming to Rule 32-206 shall be permitted for fire pump equipment.”"
Rule 32-206 has been amended to read as follows:
"32-206 Disconnecting Means and Overcurrent Protection.
(1) No device capable of interrupting the fire pump circuit, other than a circuit breaker specifically approved for fire pump service, shall be placed between the service box and a fire pump transfer switch or a fire pump controller.
(2) The circuit breaker referred to in Subrule (1) shall be labelled in a conspicuous, legible, and permanent manner identifying it as the fire pump power supply.
(3) The circuit breaker referred to in Subrule (1) shall be permitted to be used as a separate service box described in Rule 32-204.
(4) Where the circuit breaker conforming to this rule is installed in an emergency supply circuit between the emergency power source and the fire pump transfer switch, the rating or setting of the circuit breaker shall comply with rule 28-200.
(5) Where the circuit breaker conforming to this rule is installed in a normal supply circuit upstream of the fire pump controller, the rating or setting of the circuit breaker shall be not less than the overcurrent protection that is provided integral with the fire pump controller.”
Rule 32-206 has been renumbered as Rule 32-208 and Rule 32-208 has been deleted.
Appendix B Note has been added on newly developed Rule 32-206 to read as follows:
Appendix B Note on Rule 32-206: "”The intent of this rule is to only allow a circuit breaker specifically approved for a fire pump service to be installed upstream from the fire pump controller in a normal power supply circuit, or upstream from the fire pump transfer switch in an emergency power supply circuit. It is also intended by this rule that this circuit breaker could be used as a fire pump service box when permitted by Rule 32-204. When this circuit breaker is installed in the emergency power supply circuit, upstream from the fire pump transfer switch, then the circuit breaker overcurrent protection provided by requirements of Subrule (4) should be able to allow the fire pump operate up to locked rotor current condition. This will allow an emergency generator to provide necessary power to the required fire pumps while supplying all other loads connected to the generator. It is intended that compliance with rule 28-200 could be met by selecting overcurrent protection in conformance with Table D16.
The circuit breaker installed in the normal power supply circuit, upstream from the fire pump controller, should have a rating / setting that is coordinated with the integral overcurrent protection of the fire pump controller in such a manner that the upstream overcurrent device does not disconnect the circuit prior to the operation of the fire pump controller overcurrent protection.
Note: Clause 7-4.3.3 of NFPA 20(1999) requires that the controller have an instantaneous trip setting of not more than 20 times the full load current. Clause 7-4.4 of NFPA 20 requires that a fire pump controller carry locked rotor current for a period of 8 to 20 seconds.
Reference to Appendix B has been deleted from title to Rule 32-210 (as there is no Note in Appendix B on this rule).
The diagram in figure 1 is intended to clarify these new requirements of Section 32.
Thus, this little tour around application and installation requirements for fire pumps clearly indicates to the electrical practitioners that the use of the CE Code only, without understanding provisions of other codes and standards, may not be necessarily sufficient in order to meet intricate conditions for installation of this unique electrical and fire safety equipment. To be sure that this is done correctly, designers and installers are always invited to check with authorities having jurisdictional responsibility for enforcement of application and installation of fire pumps.
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