ASTM_F_1207M_-_12.pdf

Designation:F1207M12An American National StandardStandard Specification forElectrical Insulation Monitors for Monitoring GroundResistance in Active Electrical Systems Metric1This standard is issued under the fixed designation F1207M;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers electrical insulation monitor-ing devices intended as permanently installed units for use inthe detection of ohmic insulation faults to ground in active ACungrounded electrical systems.1.2 LimitationsThis specification does not cover deviceswhich are not intended for operation for:DC ungroundedsystems or AC ungrounded systems with DC componentsunless AC to DC conversion is isolated from the monitoredsystem with transformers.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 The following precautionary caveat pertains only to thetest methods portion,Section 9,of this specification:Thisstandard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.2.Referenced Documents2.1 UL Standard:UL 1053 Ground-Fault Sensing and Relaying Equipment23.Terminology3.1 Definitions:3.1.1 AC internal resistancea monitors impedance be-tween the measuring terminals and ground terminals.3.1.2 AC ungrounded electrical systema monitored sys-tem that has no intentional connection from phase or neutral toground and can continue to perform normally if one conductorbecomes connected to ground.3.1.3 DC internal resistancea monitors ohmic resistancebetween the measuring and ground terminals.3.1.4 input voltagethe supply voltage at the terminals ofan insulation monitor.3.1.5 measuring voltagethe output DC voltage from theinsulation monitor that is superimposed between the ACungrounded system and ground.3.1.6 nominal contact voltagethe voltage rating for amonitors internal relay contacts.3.1.7 nominal frequencythe frequency of a monitoredsystem.3.1.8 nominal voltagethe voltage(phase-to-phase)of amonitored system.3.1.9 response valuethe adjustable or preset set pointvalue of system insulation resistance for which an insulationmonitor will provide alarm indication.3.1.10 system insulation resistancethe total insulation re-sistance to ground to be monitored,which is measured by DCvoltage.4.Monitor Classification4.1 Type 1Insulation monitor for 115-V,3-phase or single-phase,60-Hz,AC ungrounded electrical systems.4.2 Type 2Insulation monitor for 115-V,3-phase or single-phase,400-Hz,AC ungrounded systems.4.3 Type 3Insulation monitor for 440-V,3-phase or single-phase,60-Hz,AC ungrounded systems.4.4 Type 4Insulation monitor for 440-V,3-phase or single-phase,400-Hz,AC ungrounded systems.4.5 Type 5Insulation monitor for up to 1000-V,3-phase orsingle-phase,50 to 400-Hz,AC ungrounded systems.5.Ordering Information5.1 Monitoring devices shall be ordered by specifying thefollowing information:5.1.1 Nominal voltage and frequency.5.1.2 Response value/set point range in kilohm.5.1.3 Special options,that is,test buttons,ohmeters,visualindicators,and so forth.1This specification is under the jurisdiction of ASTM Committee F25 on Shipsand Marine Technology and is the direct responsibility of Subcommittee F25.10 onElectrical.Current edition approved Oct.1,2012.Published November 2012.Originallyapproved in 1989.Last previous edition approved in 2007 as F1207M-96(2007).DOI:10.1520/F1207M-12.2Available from Underwriters Laboratories(UL),333 Pfingsten Rd.,Northbrook,IL 60062-2096,http:/.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Requirements6.1 The measuring voltage shall not increase more than10%when the monitor is supplied with 110%of the inputvoltage.6.2 The monitor shall be capable of both continuous andon-demand operation.6.3 The monitor shall have provisions for an external(remote)audible or visual alarm to operate when the resistancevalue falls below the response value,or a remote indication ofthe insulation value of the AC ungrounded system in kilohms,or both.6.4 The AC internal resistance shall be at least 250-/Vnominal voltage.The minimum resistance shall not be less than15 k.6.5 The DC internal resistance shall be at least 30-/Vnominal voltage and shall limit the measuring DC outputcurrent from exceeding 12 mA.6.6 The monitors response tolerance shall not exceed65%of the set point value at room temperature(25 6 5C(726 9F)and rated input voltage.6.7 When specified,insulation monitors shall be furnishedwith adjustable response values and designed to preclu