Diesel Engines for NFPA-20 Fire Protection Applications

1 Cincinnati, Ohio USA-Glasgow, Scotland UKDiesel Engines forNFPA-20 fire 20 Engine Type Diesel Engines for fire pump drive shall beof the compression ignition type. Spark-ignited internal combustion enginesshall not be used. ( natural gas,propane or gasoline) nfpa 20-Engine Ratings Rated at SAE Conditions 25 C (77 F ) and91 m (300 ft ) above sea level. Engines must have at least a 10% reservein horsepower. (This is a UL-FMrequirement and all UL-FM engine ratingsreflect this requirement). Engines must be derated for Altitude andTemperature. 3% Derate for every 300 m (1000 ft ) above 91m (300 ft ).

2 1% Derate for C(10 F ) above25 C(77 F ). nfpa 20 Instrument & Control Engines shall be regulated to have nomore the 10% speed difference betweenshutoff and maximum load. (Defined asdroop). Engines shall be provided with anoverspeed shutdown at 20% above ratedengine speed with a manual reset. (Onlyoverspeedshutdown or a signal from thediesel controller will shut down anengine.)DerateExample 150 hp engine Altitude 5,000 ft: CA=.86 Temperature 105F: CT=.973 Formula: (CA+ CT 1) x hp =deratedhp (.86+.973-1)=.833 x 150 hp = hp Clarke Selection/DerateCalculatorprogram can calculate the exact sizeengine you needto Setting VerificationTo verify the engine overspeed setting andfunction without overspeeding the engine,follow this procedure: Start engine manually from the controller whileholding the overspeed verification switch in the up position.

3 Observe the shutdown RPM. Test switch returns to normal position whenreleased. Reset the overspeed switch on the engineinstrument panel and restart the engine fromthe controller to verity normal operation. EXAMPLE:Rated engine speed:2100 rpmOverspeed setting:2520 rpm (120% 2100 rpm)Verification shutdown:1688 rpm (67% of 2520 rpm)JU and JW Series Instrument PanelNFPA 20 Instrumentation & Control Required Gauges: Tachometer indicates rpms Oil Pressure Gauge Coolant Temperature Gauge Hour meter record engine run time Additional Gauges: Two voltmeters one for each set ofbatteriesNFPA 20 Instrumentation & Control The engine instrument panel shall not beused as a junction box or conduit for anyac supply.

4 Interconnections between the automaticcontroller and engine junction box shallbe made using stranded wire sized on acontinuous-duty basis. The dc interconnections between theautomatic controller and engine junctionbox and any ac power supply to theengine shall be routed in separate 20 Instrumentation & Control Main battery contactors supplyingcurrent to the starting motor shall becapable of manual mechanical operationto energize starting motor. Manual toggles are provided on the Clarkeinstrument panel and additionally manualstart contactors for only the JW6H & JX6 Hseries Engines .

5 Clarke electric starting standard; One (1) starter on JW6H, JX6H units. Two (2) starters on JU4H, JU6H 20 Instrumentation & ControlElectronic Engines Engines with an electronic control module(ECM) shall have an alternate ECM wiredto produce full power in the event ofprimary ECM failure. There shall be a single ECM SelectorSwitch, with no off position, to transitionfrom the primary ECM to the alternateECM. A visual indicator shall show when theengine is running with the alternate ECM.(On both the engine panel and on thediesel controller)JX Series Instrument PanelNFPA 20 Instrumentation & ControlElectronic Engines Any sensor necessary for the function ofthe ECM shall have a redundant sensorthat shall operate automatically in case offailure.

6 A signal shall be provided to the dieselcontroller for fuel injector failure, low fuelpressure and any primary sensor 20 Instrumentation & Control Each engine shall be provided with twostorage battery units. Electrolyte shall be added to the batteriesa minimum of 24 hours prior to the timethe engine has to be started. C(40 F ) each battery shall havetwice the capacity sufficient to maintain 3minute attempt-to-start cycle (15 secondsof cranking and 15 seconds of rest in sixconsecutive cycles). nfpa 20 Instrumentation & Control Storage batteries shall be rack supportedabove the floor to prevent water damage.

7 Storage batteries shall be readilyaccessible for servicing. Storage batteries shall not be located infront of the engine mounted instrumentsand 20 Instrumentation & Control There should be two means for rechargingthe storage batteries. The battery chargers in the Diesel controller isthe primary source. The alternator on the engine is the 20 Engine Cooling The engine cooling system shall beof the closed-circuit type. Heat exchanger type Radiator typeNFPA 20 Engine Cooling Cooling water shall be piped through athreaded rigid pipe from the discharge ofthe pump to the inlet of the heatexchanger.

8 It is not permitted to use flexible tubingattached to the cooling 20 Engine Cooling The outlet for the wastewater coming fromthe heat exchanger shall be one sizelarger then the inlet. The wastewater shall be discharged into avisible open waste cone. Discharge can be piped to a suctionreservoir provided a visual flow indicatorand temperature indicators are 20 Engine Cooling Heat exchanger standard equipment. Sea water or fresh water; sacrificial anodeoptional. Engines are shipped without coolant. Cooling water line (cooling loop) shallhave a manual by-pass.

9 Cooling water line and by-pass shallinclude: indicating manual shutoff valve approved flushing-type strainer pressure regulator automatic valve second indicating manual valve or check valve pressure gaugeCooling Water LineEngine Coolant Water, ethylene glycol, inhibitor coolantmixture. 50% water 50% coolant. Coolant to conform to ASTM D4985. Heat transfer Corrosion resistance Prevents scale and sludge build up Provides freeze and boil over Protection Pre-mix before installing in engine toprevent premature engine heater 20 Engine Cooling Coolant heater is the only AC power onengine; Separate AC junction box not use controller AC for power supply.

10 Add coolant mixturebeforeapplying ACpower. All heaters single voltage; Optional ACvoltages available-location specific. Engine coolant maintained at 49 C (120 F ). nfpa 20 Engine Protection The engine shall be protected againstpossible interruption of service throughexplosion, fire , flood, earthquake, rodents,insects, windstorm, freezing, vandalismand other adverse conditions. Application: The engine must be installedinside or protected from the weather andlow 20 Room Requirements Rooms containing fire pumps shall be freefrom storage & penetrations not essentialto the operation of the pump.