Of course your explanation may be correct isf and Alf but the reason for low burden for Metering class CTs is due to the metering CTs should be accurate compared to protection class CTs in order to be accurate low burden indicates less secondary voltage which in turn less magnetising current and less magnetising current means actual current is closer to measured current.
just imagine the CT Circuit model and saturation depends on magnetising current. More is the secondary voltage more will be burden and more will be magnetising current. So if actual burden connected is more compared to rated burden than at less current (less than rated ALF or isf) CT gets saturated.
In Protection class CT we find one more class PS. In class PS CT manufacturer never specifies any burden. He specifies only knee point voltage. How much burden shall be connected to this CT?
Very nice learning
Of course your explanation may be correct isf and Alf but the reason for low burden for Metering class CTs is due to the metering CTs should be accurate compared to protection class CTs in order to be accurate low burden indicates less secondary voltage which in turn less magnetising current and less magnetising current means actual current is closer to measured current.
just imagine the CT Circuit model and saturation depends on magnetising current. More is the secondary voltage more will be burden and more will be magnetising current. So if actual burden connected is more compared to rated burden than at less current (less than rated ALF or isf) CT gets saturated.
Very useful.
Sir kindly make a lecture video on VCB selection.
very good explanation
thank you for sharing
Very good. Thanks 🙏🙏🙏🙏
Very useful. Thanks.
Thank you sir
Keep it up
In Protection class CT we find one more class PS. In class PS CT manufacturer never specifies any burden. He specifies only knee point voltage. How much burden shall be connected to this CT?
PS class CT has some other method. However its VA rating could be also determined. I shall make video on that....
@@electricaltechnologyandind5335 video awaited
How to find minimum required ALF for a relay?
If Sn will increase then we have to choose above 5P20 rating of CT
No. 5p20 will act as say 5p40