Selecting a f ire p ump.
Fire pump motor sizing.
When motor is operating after start requirement will be 1kva for 1hp i e.
For standpipe systems this flow is related to the type and size of the structure the pump is protecting.
The most common choices for fire pump drivers are electric motors and diesel engines.
In order to determine the sizing of motors and engines for aurora fire pumps we refer to the guidelines put forth by the u l as well as in factory mutual s approval standard for split case fire pumps and finally the nfpa 20 2013 4 7 6.
When designing or installing electrical power supplies for fire pumps and their accessories you must apply special rules as listed in nfpa 70 the national electrical code nec and the standard for centrifugal fire pumps cfp nfpa 20.
The last job parameter you need in order to size the fire pump is the required flow for the systems the pump will be serving sprinklers standpipes or other.
Electric motors requiring high horsepower are commonly run on 460 volt or higher three phase power.
For 480v 100hp correct conductor size is 2 0 references.
Using gensize first size the generator with the starting.
Selection of the fire pump depends on the building infrastructure and available space.
Calculating fire pump pressure requirements depending on the size and layout of your building your fire pump needs to maintain a specific amount of pressure measured in gallons per minute gpm.
Size the generator to run between 60 80 full load rating of generator.
Standards for sizing and selection of fire pumps are governed by nfpa 20.
Pump sizing does the hydraulic calculation for a centrifugal pump and estimates differential head hydraulic power motor power npsh available.
Steam turbines are also an option but are fairly uncommon.
20hp 20kva used when running.
Amps available on a generator per phase kva x 1 39.
Standard for the installation of stationary pumps for fire protection.
20kva 28amps phase over 3 phases.
Special fire pump load icon in gensize for the fire pump motor establishes a maximum allowable peak voltage dip of 15 while starting the fire pump load all fire pump loads will be included in the peak load calculations after all other loads are already running on the generator.
A a fire pump motor should be in accordance with nfpa 20 9 5 1 1 which states that it must comply with nema design b standards and be listed for fire pump service.
If a transformer supplies an electric fire pump motor size it at least 125 of the sum of the fire pump and pressure maintenance pump s motor loads and 100 of the ampere rating of the fire pump s accessory equipment 695 5 a.
In any case the demand of the system will dictate the pressure and flow required.
