Dear All,

Protection CTs are used for protection function. Their accuracy are specified at 10 to 20 times their rated current. Yet I'm still not sure about the meaning of protection. Is it referred to short circuit protection only or include also earth fault protection?

Some people recommend to use PCTs for earth fault protection since it is referred to protection class but some people argue that PCTs are not intended for use in earth fault application since their accuracy will be low for low current ( rated current ) measuring. In stead they recommend to use MCTs for this application. Who are correct? Or both MCTs and PCTs can do their work properly for earth fault protection?

Thanks in advance

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Split from MCT vs PCT.