POWER SUPPLY REQUIREMENTS FOR ELECTRIC MOTOR-DRIVEN FIRE PUMPS
Administrative Rule Adopted by Portland Fire & Rescue Pursuant to Rule-Making Authority
To ensure an adequate and appropriate power supply to electric motor driven fire pumps; to develop a joint Fire Bureau and Bureau of Buildings policy establishing minimum requirements for primary and alternate sources of electrical power for electric fire pump installations in both existing and new buildings.
This policy applies within areas served by Portland Fire & Rescue. It will apply only at the time a permit is required for the installation of electric motor driven fire pumps. It does not apply to existing installations except when pumps or power supplies are being replaced. This policy does not apply to diesel engine driven fire pump installations.
Portland's Bureau of Buildings and Portland Fire & Rescue have had conflicting policies and procedures to regulate the installation of electric fire pumps. This disparity has caused confusion and uncertainty on the part of building owners and contractors installing fire pumps. The primary issues arise* when it is unclear when a fire pump is required and what rules apply to its installation. The intent of this policy and procedure is to resolve these conflicts.
In the process of writing this policy the two Bureaus asked for assistance from interested and involved individuals. A policy committee was formed which included fire installers, designers, insurance underwriters and city staff from Electrical Section and Fire Bureau. The following policy is a result of this cooperative effort.
1. The power supply shall be installed in accordance with NFPA 20 and the National Electric Code (NEC) unless otherwise stated in this policy, and shall be installed as an emergency power source.
2. The following items from NFPA Standards have been overlooked on many fire pump installations. They are restated here to emphasize their importance in all installations of electric motor-driven fire pumps:
a. Electric power for electric fire pumps shall be supplied ahead of all building/plant disconnecting means.
b. The primary power supply shall be sized for locked rotor currents.
c. When alternate or secondary power sources are supplied or required, they shall be connected with an approved transfer switch and provided with selective automatic load pickup and load shedding.
3. Special Criteria:
(See item IV for criteria for approved alternate emergency power source)
a. HIGH CHALLENGE STORAGE WAREHOUSES e.g. high piled stock flammable, aerosol storage (new or existing retro fitted with sprinklers or modified for high challenge product storage)
* Electric motor-driven fire pumps serving high challenge storage warehouses, as defined by the Fire Marshal are not required to have an approved alternate emergency power source.
b. NEW HIGH-RISE BUILDINGS (Over 75 'in height)
The alternate emergency power supply shall be an engine driven generator.
ii. All UBC and NEC requirements must be met.
c. EXISTING HIGH-RISE AND ALL NEW AND EXISTING BUILDINGS NOT OTHERWISE COVERED
An approved alternate emergency power source is required.
EXCEPTION: No alternate power source is required when all the following conditions can be met:
i. The commercial power supply serving the specific Property is not at risk of failure beyond what is normal or safe as determined jointly by the Fire Bureau and Electrical Section. (Documentation shall be provided if the commercial power supply is designated to be "at risk.")
ii. The fire suppression system is served by pressure water mains capable of supplying the required pressure to the two (2) most remote sprinkler heads without fire pump assistance (excluding fire hose requirements).
iii. Fire apparatus can provide adequate pressure (this provision is not met if, in the judgement of the Fire Marshal, fire apparatus response may be delayed by factors such as long response distances, limited access - across rail tracks which could be blocked - or a history of delayed response.
iv. Sprinkler system water flow is monitored by an approved central station.
4. Approved Alternate Emergency Power Sources
All alternate power sources must be provided with approved automatic transfer switches and be capable of selective load pickup and shedding.
The following are approved alternate sources of power:
a. A service tap from a utility power source separate form the one supply the primary power (a one-hour, fire resistive separation or 2" of concrete is considered adequate).
b. In the downtown Portland area supplied by the grid system or in areas supplied by a comparable system, a tap ahead of the existing service supplied from the secondary grid, provided necessary measures are taken to keep the two systems separated and remote so as to minimize the possibility of simultaneous power disruption due to fire or other hazards -(a one-hour resistive separation or 2" of concrete is considered adequate).
c. Engine driven generator sized to accommodate the running currents of the fire pump plus all other loads to be supplied.
5. Other Requirements:
a. Fire pumps shall be installed in accordance with t& currently adopted edition of NFPA 20 and NFPA 70. Specifically, these requirements include:
A separate controller for each fire pump.
When an alternate power supply is required, a separate transfer switch is required for each pump.
Controller and transfer switches are to be listed or approved for "fire pump service."
iv. Transfer switches separate from controllers may be used only if they are listed or approved for "fire pump service."
6. Special Problems in Downtown Area
Fault cur-rents in the downtown grid are high. It is the responsibility of the electrical contractor or engineer to investigate existing fault current conditions and select equipment accordingly.
Filed for inclusion in PPD June 13, 2003.
Originally adopted by Fire Marshal as Fire Prevention Division Policy Manual Document H-6, effective September 10, 1987, revised May 14, 1996.