An ordinary industrial motor controller follows a "no start, no run" logic: if something looks wrong, it stops. A fire pump controller is built on the opposite idea. Its job is to start the pump and keep it running during a fire, even when abnormal conditions occur, wherever that is possible.
Key NFPA 20 principles
As summarized by a specialist trade article, NFPA 20 treats conductors and some supply equipment as expendable so the pump can keep running. In practice this leads to rules such as:
- External circuit failures, open or short circuits, must not prevent the controller from starting the pump.
- Remote stop buttons are not allowed.
- Overcurrent sensors must be non-thermal, and protective devices must not have a memory that affects reset time.
- Undervoltage, phase-loss or other sensors cannot block operation of the motor contactor.
- An external device may start the pump automatically only by opening a normally closed contact.
- The controller must have an emergency-run handle or lever that closes the contactor mechanically.
- The controller cannot be used as a junction box for other equipment.
It must be listed for fire service
A fire pump controller must be specifically listed, approved and labeled for fire suppression use. A general-purpose motor starter, however capable, does not meet this requirement.
Power supply and transfer switches
Where the authority having jurisdiction considers the normal power supply unreliable, an automatic transfer switch is required. It can be upstream, combined with the controller or separate, and can transfer to a second utility feed, on-site power production or a diesel generator for standby power.
What this means when you specify
- Ask for a controller listed for fire pump service, not a standard starter in a larger enclosure.
- Do not add remote stop buttons or other devices that can inhibit starting.
- Check with the authority having jurisdiction whether a transfer switch and standby source are required.
- Keep the controller dedicated: no other equipment is wired through it.
Related pages
See our fire pump controllers and fire pumps pages, the 2500 gpm skid and container packages, and the Pumpsense selector. To understand pump sizing, read fire pump rating: the 150% point and 65% pressure.