cr4 - thread_ ct differences
Post on 17-Dec-2015
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ThemajordifferencebetweenthemeasuringCTsandProtectionCTsare:
(1)ThemeasuringCTsaremoreaccuratethantheprotectionCTs.ThemostcommoncompositeerrorlevelsofmeasuringCTsare0.5and1,whilethemostcommoncompositeerrorlevelsforprotectionCTsare5and10.
(2)ThesaturationlevelsofprotectionCTsaremuchhigherthantheCT'scurrentratings.ForprotectionCTs,itis10,15,20or30timeshigher,whileformeasuringCTitisatbest2times.
(3)ProtectionCTcanbeusedforthecoursemeasuringpurpose(notaccuratemeasurement),whilemeasuringCTshallnotbeusedforprotectionpurposebecauseoflowsaturationlevel.
(4)TheCTclass(IEC60044)forprotectionCTisdenotedby'P'(example5P20),whilethemeasuringCTisbyM(example1M)
Seethefollowinglinksforadditionalhelp:
http://cr4.globalspec.com/thread/43440
http://www.itluk.com/introductionprotectiontransformers.html
http://community.myelectrical.com/wikis/myelectricalwiki/ctdimensioning.aspx
http://cr4.globalspec.com/thread/51403
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