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 3.2.5.7 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 3.2.5.19 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 3.2.4.9. (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.
Ark Tsisserev, P.Eng., is the chief
electrical inspector for the city of Vancouver, Canada.
He is a registered professional engineer, with a master’s
degree in electrical engineering. He is currently the
chairman of the technical committee on the Canadian
Electrical Code and represents the CE Code Committee on
NEC CMP-1 as the CMP-1 non-voting member. Ark is
presently the third vice president of the Canadian
Section.
With the permission of
Canadian Standards Association, material is reproduced
from CSA Standard, CSA Standard C22.1-06, Canadian
Electrical Code, Part I (20th Edition), Safety Standard
for Electrical Installations, which is copyrighted by
Canadian Standards Association, 178 Rexdale Blvd.,
Toronto, Ontario, M9W 1R3. While use of this material
has been authorized, CSA shall not be responsible for
the manner in which the information is presented, nor
for any interpretations thereof. For more information on
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