CT class X
CT class X
(OP)
This is a IEC world background question.
Class X CT were firstly define in British Standard 3938 now obsolete.
High Z scheme ( such as REF) are still use, therefore the need for such CT.
Such CT call for Vk, Rct and Imag requirements.
IEC 60044-1 define class PX with the same requirements.
Inside 60044-6 is found class TPS with similar datas.
People still abuse class X while dealing with such CT.
Should I refer to PX or TPS class when dealing with REF protection scheme?
Regards.
Class X CT were firstly define in British Standard 3938 now obsolete.
High Z scheme ( such as REF) are still use, therefore the need for such CT.
Such CT call for Vk, Rct and Imag requirements.
IEC 60044-1 define class PX with the same requirements.
Inside 60044-6 is found class TPS with similar datas.
People still abuse class X while dealing with such CT.
Should I refer to PX or TPS class when dealing with REF protection scheme?
Regards.






RE: CT class X
Class TPS CT is for special transient performance requirement, I understand. I haven't come across this class in actual use till date.
Class PX is the traditional Class PS or Class X CT and is relevant for high impedance differential / REF protection etc.
RE: CT class X
thank you for the reply.
I went though standard more carrefully this time and your answer make sense.