Generator Set Ratings Guidelines (TIB-101)

1 TIB-101 9/00c1 TECHNICAL INFORMATION BULLETINTIB-101 9/00cGenerator Set Ratings GuidelinesGenerator set Ratings Guidelines are designed to sizethegeneratorsettomeettheloadrequirem entsofanapplication. Thefourtypesofgeneratorsetratingsarestan dby, prime power, limited running time, and baseload(continuouspower).Considerbuildi ngexpansionandfuture loadadditionswhen determining Generator set loads. The averagepowerrequiredofageneratorsetisaca lculatedvalue, life expectancy mean time between overhauls(MTBO) and performance of Generator sets arecontingent upon application of these set life depends upon engine load factors,fuel and lubeoil quality,ambient conditions,operatingload,installationqua lity, chart on page 3 shows a typical engine MTBO curve.

2 Generator set performance and overhaulintervalsvarywithoperatingload. Asengineoperatingloaddecreases, ,reducingtheloadonanengineincreasestheti mebetweenoverhauls. common throughout the industry. Governmentagencies, military agencies, and other sources maypublish their own definitions and Ratings , However,duetodifferences in manufacturing standards, each enginemanufacturer may have different engine toleranceswhich affect engine Ratings and, in turn, Generator setratings. Refer to this section for rating standards RatingStandby rating applies to installations served by areliable utility source. Standby power is applicable tovarying loads for the duration of the utility powerinterruption.

3 There is no overload capability for thestandby rating; use of the Generator set above thestandbyratingisprohibited. RatingsareinaccordancewithISO3046/1,BS55 14,AS2789, load factor of x% of the standby rating, with100% Typicaloperatingtimeis400hoursperyearorl ess. Usetheprimepowerratingforapplicationsexc eeding 400hours typical standby application backs up the the following formulas to determine the standbyrating:=Standby=(P1xT1)+(P2xT2)+( P3xT3)+(P4xT4)+(P5xT5)+..(PnxTn)AverageP owerT1+T2+T3+T4+T5+T6+..TnAveragePowerRa ting x%LoadFactorP=PowerinkWT=TimeinhoursS=Sh utdownornonrunningtimes(notusedincalcula tions)StandbyRating,100%TimeAveragePower ,x%ofStandbyRatingT1T2S1T3T4S2T5T6S3P1P2 P3P4P5P6 ProhibitedPowerTIB-101 9/00c2 Prime Power RatingPrimepowerratingappliestoapplicati onswhereutilitypowerisunavailableorunrel iable.

4 Atvaryingload,thenumberofgeneratorsetope ratinghoursatprimeratingisunlimited. RatingsareinaccordancewithISO8528/1andov erloadpowerisinaccordancewithISO3046/1,B S5514,AS2789, anunlimited numberof operatinghours SeeRatingConditionsfollowingforprime power rating load factor for each Generator setmodel. Loads of less than 30% shall be counted as30%.A10%overloadpowerisavailableforape riodofonehourinevery12hours. prime power applications include emergencyapplicationswherefrequentpowero utagesoccur,peakshaving and interruptible rate, backup for unreliableutility sources, or as a sole source when a utility :=PrimePower=(P1xT1)+(P2xT2)+(P3xT3)+(P4 xT4)+(P5xT5)+..(PnxTn)AveragePowerT1+T2+ T3+T4+T5+T6+.

5 TnAveragePowerRating x%LoadFactorP=PowerinkWT=TimeinhoursS=Sh utdownornonrunningtimes(notusedincalcula tions)PrimePowerRating,100%TimeAveragePo wer,x%ofPrimePowerRatingT1 MaximumOverloadRating,110%T2T3T4T5T6T7T8 T9P10S1S3S2T10 Prohibited30%Anyloadlessthan30%(P5)shall becountedas30%PowerP1P2P3P4P5P6P7P8P9 Limited Running Time RatingLimited running time rating applies to Generator setsoperating under nonvarying load factors is continuously supplied to a constant ornonvaryingloadupto100% overload capability is available at this rating;therefore, use above limited running time rating isprohibited. Foroperationexceeding700hoursperyearatco nstantloadusethebaseload(continuousratin g).Typical limited running time applications include loadmanagement, peak shaving, interruptible rate, loadcurtailment, and cogeneration.

6 Contact a factoryrepresentative for Generator set limited running (notusedincalculations)ProhibitedPowerP1 T2 TIB-101 9/00c3 Base Load (Continuous) RatingBaseloadrating(alsoreferredtoascon tinuousrating)appliestogeneratorsetsoper atingasutility-typepowersourceswherether earenonvaryingloadfactorsand/orconstant dedicated loads. Power is continuouslysuppliedtoaconstantornonvary ingloadupto100% overload capability is available at this rating;therefore, use above base load rating is ,ISO3046/1,BS5514, AS2789, ,baseload,main source of electrical power, and (notusedincalculations)ProhibitedPowerP1 T2 Typical Engine MTBO CurveEngine life will vary with the following:DEngineLoadFactorsDQualityofFu elandLubeOilDAmbientConditionsDQualityof InstallationDQualityofMaintenanceProgram LoadStandbyPrimeBaseLoadEngine LifeIncreasingLimitedRunningTimeIncreasi ngTIB-101 9/00c4 Engine Rating Tolerances and Load FactorsThefollowingtablelistsengineratin gtolerancesandthestandby and prime rating load factor percentages Set ModelRatingsToleranceStandby RatingLoad FactorPrime RatingLoad FactorROZJ and REOZJ Models20--200 ROZJNone70%70%20--100 REOZJNone70%70% and ROZS Models20--40 ROZK/ROZS 5%85%75%50--170 ROZK/ROZS 5%85%75% , REOZD, REOZD-4.

7 And ROZD-4 Models200 REOZP 5%85%75%230--400 REOZD 5%85%75%450 REOZD-4 2%85%75%500--1000 ROZD-4* 2%85%75%1250--2000 ROZD-4 2%85%75%EngineratingsarebasedonSAEJ1995a ndISO3046.* Somemodelsdonothaveprimepowerratings; Models600 ROZM 2%60%60%900 ROZMNone60%60%1000 ROZM 2%60%60% Models20 RZNone70%70%30--45 RZNone70%70%50--70 RZNone70%70%80/100 RZNone70% Models30--100 RZG 5%82%65% Models135--275 RZDNone70%70% Mobile and Marine Models[AllGasoline-andDiesel-PoweredMode ls 5%NotApplicableNotApplicableEnginerating sarebasedonISO3046andISO8528-1.[]]