1. NFPA 20 controller: UL 218 or NBR 16704 Annex C
An electric fire pump controller is a critical and specific component, not an ordinary electrical panel. It must perform a unique function in the industrial electrical world: ensure the pump starts on demand, keeps running without interruption, and cannot be accidentally shut off.
To perform this function, the controller undergoes specific certification — UL 218 (Underwriters Laboratories Standard for Service Equipment for Electric-Driven Fire Pumps) for projects following NFPA 20, or NBR 16704 Annex C for projects under the Brazilian standard. Both certifications require pressure-drop start logic, real-time supervised alarms, event memory for later audit, and an independent internal battery to keep logic operational even on controller power failure.
The choice between UL 218 and NBR 16704 Annex C is not arbitrary. For projects in buildings insured by international companies (FM Global, Zurich, AIG), UL certification is typically a contractual requirement — insurers do not accept components without this mark. For domestic buildings without international insurers, the NBR 16704 Annex C controller fully meets Fire Department requirements and is accepted in all state technical instructions.
FB Bombas supplies skids with controllers in both configurations per customer requirement, working with certified national suppliers (Eaton Brasil, Schneider Electric Brasil) and international suppliers for UL projects (Tornatech, Firetrol).
2. Starting methods: Y-delta, soft-starter and DOL
An electric fire pump starts under load, against system pressure and often with the sprinkler or hydrant circuit already demanding flow. This means high starting current — on a 150 HP motor starting DOL (Direct On Line), current can reach six or seven times nominal, disturbing the facility's electrical grid and in extreme cases causing voltage drop at other critical building equipment.
To avoid this transient, NFPA 20 and NBR 16704 allow three starting methods: DOL (direct starting, acceptable only on smaller motors, typically below 50 HP), Y-delta (star-delta starter, reduces starting current by about 1/3), and listed soft-starter (electronic device that reduces current more smoothly and progressively).
The choice between the three methods has both operational and normative implications. Y-delta is the most economical solution and remains accepted by NFPA 20 in most projects, but introduces a small interruption during the star-to-delta transition — which may be undesirable in sensitive applications. Soft-starters are more expensive but provide smooth transition without interruption, reduce mechanical wear on the coupling and motor, and allow fine-tuning of the starting ramp.
For both, NFPA 20 requires the starting device to be listed specifically for fire pump service — a generic industrial soft-starter does not qualify. FB Bombas specifies the starting method per power range: Y-delta for motors between 50 and 150 HP in standard projects, listed soft-starter for motors above 150 HP or when the customer requires smooth transition.
3. Manual bypass, transfer switch and minimum run timer
Three NFPA 20 controller components frequently generate confusion in Brazilian projects and deserve specific explanation. The first is manual bypass: a circuit parallel to the starting device (Y-delta or soft-starter) that lets the operator put the pump in full DOL in case of primary device failure.
NFPA 20 section 10.4.3.3 requires bypass for soft-starter controllers — if the soft-starter fails at combat time, the operator must be able to directly energize the motor via mechanical bypass, accepting the starting current transient as the lesser evil versus the pump not starting. The bypass is a manual switch, lever-operated, inside the controller panel.
The second component is the transfer switch (ATS — Automatic Transfer Switch), required when the installation has two electrical sources (utility + generator, or two substations). The ATS detects primary source loss in real time and automatically transfers to the alternative source without interrupting pump operation. NFPA 20 requires the ATS to be listed and to have transfer time compatible with maintaining motor rotation (typically under 10 seconds).
In installations with only one source, the ATS is not needed, but the diesel reserve becomes required in its place to ensure continuity.
The third component is the minimum run timer. Once the pump is activated by pressure drop, the controller starts a minimum operation timer — typically 10 minutes. Even if pressure is restored before that time, the pump keeps running until the timer expires. This prevents repeated start-stop cycling (hunting) that wears the motor and coupling in case of small pressure oscillations. After the timer expires, the pump only stops by manual operator command — never automatically.
This combination — minimum run timer + manual shutoff — is what operationally distinguishes the fire pump from a conventional industrial pump with automatic control.
4. Why shutoff is exclusively manual
NFPA 20 section 10.5.2.1 requirement that the fire pump may only be stopped by manual operator command is one of the most important — and most frequently misunderstood — rules of the standard.
The logic behind it is simple when you think of a real combat scenario: during a fire, a brigade member opens a hydrant and begins fighting the fire; this causes abrupt pressure drop in the system; the main pump starts automatically and restores pressure.
But combat frequently involves stabilization moments — the brigade member partially closes the nozzle to reposition, pressure temporarily rises, and if the pump had automatic high-pressure stop, it would shut off exactly when it was most needed.
Mandatory manual shutoff eliminates this risk: the pump, once activated, keeps running until someone — typically the pump room operator or combat commander — consciously assesses that the fire is controlled, the threat has ceased, and it is safe to shut off the pump. The stop command is physical, via specific button on the controller panel, and generates a record in the event memory.
If this button is triggered by mistake during a real combat, the responsible person will have to justify the action in subsequent investigation.
5. Electric motor: IP55 class F insulation
The electric motor used in a fire pump follows distinct specifications from a common industrial motor. The minimum protection degree is IP55 (protection against dust and water jets), ensuring the motor operates in a pump room with high humidity and eventual water leaks from the system itself. The insulation class is F (maximum winding temperature of 155 °C), allowing temporary overload without compromising service life.
Construction is TEFC (Totally Enclosed Fan Cooled), with an integrated fan cooling the motor even when the pump room lacks forced ventilation. Power is sized to deliver 100% hydraulic demand with adequate safety margin — NFPA 20 requires the motor to be capable of operating at 150% of rated flow without entering thermal overload.
FB Bombas works with WEG and Siemens motors in electric skids. WEG (Brazilian manufacturer headquartered in Jaraguá do Sul-SC) is the most common option in national projects — the W22 line fully meets IP55 and class F requirements. Siemens is used when the project follows an explicit international standard required by the customer. Both manufacturers provide INMETRO-certified motors per Ordinance 179/2010, and each motor's certification documentation accompanies the skid at delivery.
6. NFPA 25 monthly test: no-flow start and verification
NFPA 25 section 8.3 defines the mandatory monthly electric pump test: the pump is started via manual command at the controller (not depending on pressure sensor), runs for minimum 10 minutes at churn (zero flow, closed discharge and open circulation relief valve), and is monitored by a casing thermometer to confirm the circulation relief valve is properly draining heat.
During these 10 minutes, the operator visually checks controller panel status, confirms all alarms inactive, records suction and discharge pressure, and notes any anomaly. At the end, the pump is stopped via manual button.
This simple test has two operational purposes. The first is to confirm the pump works — that the motor starts, reaches nominal rotation, and maintains stable pressure at churn. The second is to keep the rotating assembly in regular use, preventing bearings, packing and seals from sitting idle for long periods that would accelerate their wear.
The entire procedure is documented in a form attached to the building's fire-fighting system inspection log, which is kept in the pump room and presented at Fire Department inspection or insurer audit.
