Selecting the right fire pump driver and starting method is not just a matter of performance—it is a critical requirement for life safety and property protection. According to NFPA 20, the Standard for the Installation of Stationary Pumps for Fire Protection, every fire pump driver must be sized to exceed the maximum brake horsepower (BHP) requirements of the pump at any point on its curve. Ensuring your system meets these rigorous standards is the foundation of a reliable fire protection strategy.
The Three Main Driver Types
Fire pumps are typically driven by one of three primary methods, each with specific applications and regulatory requirements:
Electric Motors: The most common choice where reliable utility power is available. They are known for their ease of maintenance and straightforward operation.
Diesel Engines: These must be UL Listed or FM Approved specifically for fire pump service. They are essential for sites where electric power is unreliable or as a backup to electric pumps.
Steam Turbines: Used primarily in industrial settings where a consistent high-pressure steam supply is already present, offering a robust alternative to motor or engine drivers.
Choosing the Right Electric Starting Method
For electric fire pumps, the method used to start the motor impacts the electrical service design, starting current (LRC), and mechanical stress on the pump. Below is a comparison of the industry-standard starting options to help guide your selection:
Across the Line (ATL): Uses full voltage, providing the lowest cost and highest torque, but can cause mechanical shock.
Primary Resistance: Provides smooth starting and is flexible, but involves high power loss and higher costs.
Soft-Start: Offers smooth, adjustable acceleration and reduced mechanical stress, though it comes at a higher cost and complexity.
Part Winding: A popular choice for medium torque needs, requiring a special motor and not suitable for frequent starts.
Wye-Delta: Reduces motor strain with low starting current and torque, but requires a specific delta-wound motor.
Auto Transformer: Ideal for hard loads with adjustable torque, but can cause machine shock and is higher in cost.
Conclusion: Reliability Starts with Selection
Properly selecting a fire pump starting method is critical for maintaining system reliability and ensuring the longevity of both the motor and the pump. By balancing cost, starting torque, and the limitations of your electrical utility, you can ensure that your fire protection system will perform flawlessly when it is needed most. Always consult with specific fire pump controller literature and a qualified fire protection engineer prior to finalizing your electrical service design.