Fire Pump Drivers

The principal objective of a fire pump driver is to provide the pump with motive power under any circumstances. Usual drivers are electric motors, diesel engines or, to a lesser extent, steam turbines. Although the reliability of the drivers themselves does not really pose problems, careful consideration must be given to the dependability of the power supply for electric motors and turbines, and to the fuel supply for diesel engines. Very complete regulations exist in every country which must be considered.

Electric motors are the most economical driver type when a reliable power source is available. If this is not the case, power must be supplied by two or more independent sources, one of which may be an emergency generator set. Another choice might be to use one motor-driven pump and one diesel engine-driven pump. General guidelines for electric drives are

• Motor power and speed must be selected in accordance with the pump characteristics.

• Depending upon codes and available current, wound rotor, star delta, wye delta primary resistance, or part-winding start motors may be used.

Diesel engines are frequently used to drive stationary fire pumps. Equipped with battery packs and automatic controls, they rival electric motors for reliability and eliminate concern over the dependability of the source of electric power. In order to guarantee the fuel supply, the tank must be located above ground at an appropriate height. The prevail ing philosophy of a diesel engine driven pump is that "the pump must run" in actual fire conditions. All engine failures (oil pressure, cooling water temperature, speed) should be indicated only, and should not stop the engine. The only exception to this is the NFPA 20 requirement that a shut-down occur at an over speed of 120%.

Here are some general guidelines for diesel engines:

• Engine power and speed must be selected in accordance with the pump characteristics (diesel engines are very sensitive to altitude and ambient temperature).

• All energy sources for engine starting must be doubled: two batteries, or two air containers, or electrical and manual recharge of the hydraulic starting system, and so on.

• An instrument panel secured to the engine at an appropriate place must include a tachometer, an hour meter, an oil pressure gage, and a water temperature gage.

Occasionally, a fire pump is driven by a steam turbine. When it is desirable to use steam as the power source, details of the steam supply and exhaust need to be carefully planned to ensure that the required level of reliability exists.

Survival Treasure

Survival Treasure

This is a collection of 3 guides all about survival. Within this collection you find the following titles: Outdoor Survival Skills, Survival Basics and The Wilderness Survival Guide.

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