Differential protection 

Much appreciated!

thanks for the kind feedback Ryan!!

Am glad you found them useful!!

Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks

Glad you liked it

Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks

Glad it was helpful!

Hi

Glad you like them!

Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WETT1001 to get them for $9.99 Regards Stephen Brooks

Hi Michael, The CT will measure current in both directions, the relay is set up to operate when the current is in either the forward or reverse direction to make it possible to identify the fault locations, please refer to the full Udemy protection course for details. Regards steve

@@Electricalsteve Steve thanks for the reply. I purchased about 70 quids worth of courses a few weeks ago. I think all of them except 1 that you had available. I would really love to have the option to ask you more questions as and when they arise throughout this course. Can I leave you my email and you send me a message so there is always the option for help? I would really appreciate it and I'll tell you more about what I do for a living and how your knowledge will help me develop. Thank you

Good

Hi Aminul, this subject is not covered on this video steve

Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks

Thanks

Thanks!!

Hi, it’s not really an ANSI/IEC conflict, most utilities only have one set of current transformers on the line side now to save money and use other protection functions to detect a fault in between the CT / circuit breaker ( short stub fault ). Steve

@@Electricalsteve Maybe it's a regional thing. I commission HV substations, including the apparatus outside and the protection systems inside the control house. Our standard new dead tank circuit breakers have a total of 18 CT's per breaker. For a line breaker the bus side CT's are used for primary and secondary line protection and the line side CT's are for primary / secondary bus protection. Having the diff CT's on line side ensures the breaker itself is covered in the diff scheme. In a ring or breaker and a half scheme, it may be a little different. One last set of CT's may be used for breaker failure protection and the last may be for revenue metering. We have older installations that don't have as many CT's (we call CT deficient), but that can cause issues down the line - shared CT circuits and someone does maintenance test with doble -plugs paddle in while connected to doble and shorts diff relay and a nuisance trip. I believe for the relative low cost of additional CT's on a dead tank, many utilities choose to have the extra CT's for flexibility and ease of wiring and maintenance. Digital relays also help quite a bit if sharing CT's as the polarity can be adjusted internally in the relay for compensate.

Thanks

Thanks for the suggestions...will see what I can do. steve

Always welcome

Most welcome

Sir please Explain - Schneider micom relay P125 P222 All functions...

Hi Vinod, the full protection courses on Udemy explain all of the functions in detail steve

@@Electricalsteve ok sir thank you Please suggest link

Hi, Go to the Udemy website, search for courses under my name ( Stephen brooks ) & use the voucher code WERD1001 to get them for $9.99, vouchers expire in 5 days. Regards Stephen Brooks

Welcome

Hi Subham, Equipment used on electrical networks is designed to carry fault current for a certain time period, normally 1 second or 3 second dependant on the application. This allows time for the protection systems to detect the fault and open the circuit breakers, clearing the fault from the network steve

Hi, The 5P20 CT’s will be less accurate than the class X CT’s, this will become clear if you have a high current fault and the relays at the two ends will show different current levels, this difference may in incorrectly identify a fault on the line being protected. Regards Steve

@@Electricalsteve tq steve..👍

Thanks!!