Transformer Overcurrents Part 1

In the first part of a four part series, we look at determining the size of primary O/C, as well as Primary Feeder and Secondary O/C when primary is omitted. This video is specific to transformers over 750V. This video is intended as supplementary information for academic purposes, and is in no way intended as instructions for installation purposes. Please contact local supply authorities for specific information in your area.

[@orlandowall5523]

CEC2021 26-250 Overcurrent protection for power and distribution transformer circuits rated
over 750 V

[@linuxbrad]

How are you writing backwards so well? From your perspective you're writing backwards right? How?

[@schulerruler]

Haha that would be awesome if I could say yes, but no. I write normally, on the backside of the glass it looks backwards and the camera flips the image 180°. Thanks for watching and commenting!

[@Sheamus1212]

Great stuff. This was so clear and easy to follow. I recently took a course and the teach just zoomed through these calcs

[@schulerruler]

Thanks for the support my friend!

[@الْحَمْدُلِلَّهِرَبِّالْعَ-ل5ب]

Thank you for this effort

[@AliAbbas-wo6qq]

Thank you sir it was very clear and very useful for me

[@schulerruler]

I am happy it was able to help you! Thanks for watching!

[@enriqueh8847]

Thank you for your teaching. Please, could you do one video alla about overload for power transfomer for high voltage substation in which are types of ONAN - ONAF -OFAF, etc. and According to "IEC standard or IEEE " what are maximum overload power in which transfomer can work without get damaged in its useful life time. For example, I see sometimes overload power transformer until 105% which is used in PV power plant connect to power network at HV side and listen to that will not be problems because transformer will work from 06:00 h to 18:00h (and exceed nominal power from 10:00h to 14:00 h) becasue in the evenning there is not irradation so the solar panel will not product energy. Antoher question what will be future problems on life time. Please, if it is possible to do one video all about overload according to International Standard and How to be designed or sized one power transfomer and why, etc. it will be better. In advance, Thank you very much.

[@MrEcnerual]

Is it not a conflict between conductor sizing and overcurrent protection since conductor can be sized at 125% both on the primary and secondary while overcurrent protection is sized to 150% on the primary to protect the transformer?

[@davemembrere2160]

You make it easy to understand the codebook, please keep making more videos like this. Thank you!

[@a_cool_daddy2918]

Great explanation. Thank you.

[@chriswilson9049]

How would you go about doing the problem if you didn't know the angle of the inductor?

[@Al-wu8is]

God bless you.it'a perfect job and helped me a lot.

[@abdalrahmanelshora8062]

Thanks sooo much for the amazing tutorial. Your explanation is really wonderful and amazing

[@schulerruler]

You're very welcome!

[@kadadjebli2380]

excellent video thank you

[@crystalclear3510]

Good stuff! Thank you.

[@luicbryantconcepcion8729]

Hi sir do you have a video of sizing a teansformer base on the calculated load of a building .. something like that.. then it indicates what kind of conductor should be use and overcurrent device to protec the transformer.. thanks .

[@dravenadonis8952]

instablaster

[@aouesrachid7089]

thank you

[@mugalahenry8097]

Which table are you considering?

[@mugalahenry8097]

For overs and unders?

[@schulerruler]

Do you mean for the selection of overcurrents, or to determine whether permitted to go up or down?

[@LivinLaVidaFam]

very good video . thank you

[@schulerruler]

Thank you for watching!

[@brimmedHat]

this rules. thanks for the help

[@brimmedHat]

if I could suggest, if you are gonna do more videos in the future, would be to edit in screenshots of the CEC from the PDF for things like tables and to quickly review the the rules referred to. also the audio clarity and gain could be improved.

[@taoufikcanada5673]

I subscribe Good Job

[@schulerruler]

Thank you for subbing and for the kind words!

[@bacon525]

4160 is actually the phase voltage already (2400V * root3)

[@schulerruler]

That would not be a phase voltage if you are increasing by root 3, that would be a line voltage from a WYE supply if that was the case.

[@bacon525]

@@schulerruler Oh. Well wikipedia calls the line voltage L to N and the phase voltage L to L.

[@schulerruler]

@@bacon525 it would really depend on the system. A delta system, line voltage and phase voltage are one and the same, however the line to line voltage in a WYE system would be 1.732 times higher than the line to ground or line to neutral voltage. This is the voltage that is known as phase voltage. What is the wikipedia site out of curiousity, I'd like to see what their references are to see if I'm missing something in particular.

[@bacon525]

It's the wiki page on 3 phase ac. Actually I think I got them reversed.