Specificationsforneutralgroundingresistors(Lowresistance)

SpecificationsforNeutralGroundingResistors(LowResistance)

1.0SCOPE

Thisspecificationcoverstheminimumrequirementsforthedesign,materials,manufacturing,inspectionandtestingoflowresistanceneutralgroundingresistors.

2.0CONFORMANCETONATIONALSTANDARDS

Theneutralgroundingresistorsshallbedesignedandfactory­testedtoIEEEStandard32­1972.TheneutralgroundingresistorsshallbedesignedtomeetallapplicablespecificationsofANSI,NEC,NFPA,NEMA,andOSHA.TheneutralgroundingresistorsshallbedesignedtoconformtoSeismicZone2requirementsoftheUniformBuildingCodeunlessotherwisespecified.

3.0SERVICE CONDITIONS

Neutralgroundingresistorsshallperformsatisfactorilywhenoperatedina120°Fmaximumambienttemperature,0°Fminimumambienttemperatureandanaltitudeof6000feet(1829m),orlower.

4.0RATINGS

Theneutralgroundingresistorsshallbemanufactured by Advanced Power Technologies, Inc.

NeutralGroundingResistorAssembly,rated for4160 or 12470 or 13800SystemVolts,2400 or 7200 or 8000VoltsL­N,200Amps,10seconds,760CRise,Outdoor(NEMA/3R/IP23),bottomentryandexit.

Measures approximately 38incheswideby38inchesdeepby30incheshighandweighing240lbs.

5.0DESIGNDETAILS

The unit shall be enclosed in outdoor type safety enclosure and shall be fully assembled. Neutral current transformer shall be installed in the resistor enclosure with secondary leads wired to the terminal blocks for field interconnection to the generator ground fault relay.

Eachresistorshallbecompletelyfactory­assembled,suitableformountingonalevelpadoratopthetransformer.Enclosuresshallbesafetyenclosures,theyshallbeproperlyinsulatedfromtheresistorelementandframesub­assemblyandgrounded,theyshallbeprovidedwithopeningsforentryandexitconduitssothattherearenoexposedlivepartsoutsideoftheenclosure.Enclosuresshallutilizecorrosionresistanthardwarethroughout.

6.0MATERIALS

Eachresistorunitshallbestainlesssteeledge­woundtypewithweldedstainlesssteeljumpersbetweenunitresistors.Theedge­woundhelixstrapshallbewoundaroundaonepiecerefractorycorereinforcedbyalongitudinalsteelthroughrod.Eachresistorunitshallbedesignedtopermitthermalexpansion.

7.0NAMEPLATES

The nameplates shall be produced from clear textured polycarbonate, laminated on high performance pressure sensitive adhesive. The printing shall be done on the interior surface of the laminate to avoid scratching or other deterioration of text. The lettering shall be white on black background.

8.0DRAWINGS

Thesuppliershallsubmitapprovaldrawingswithin5­10workingdaysafternotificationofcontractaward.Drawingsshallshowassemblyoverallweight,exteriordimensions,mountingboltdimensions,andterminallocations.Drawingsshallshowanelementarywiringschematic.

9.0TESTS

ManufacturershallperformallstandardtestsprescribedbyNEMA,ANSI,andIEEEStandard32­1972andshallberesponsiblefortestingcircuitstoinsureproperfunctionperformanceandoperablecondition.

10.0MANUALS

SuppliershallsubmitcompleteInstructionandMaintenancemanualsatthetimeofshipment.Themanualsshallgivecompleteanddetailedinstructionsforunpacking,installation,inspection,connection,andmaintenance.