What is FERRORESONANCE?

[@CylestaOfficial]

This was a really well explained video, thank you!

[@allanlathan4614]

Great and easy to understand explanation of a complicated subject. Thank you.

[@hilineacademy8482]

Thankyou sir.👍

[@jeffreykornspan9053]

Never doing HV feeders or transmission, I thank you for your demo, Cody It's never too late to learn. I knew very well about reactance and capacitance. We were always told to keep no load on a service upon energizing! So much for that theory!

[@hilineacademy8482]

Lol. Ya I hear ya. There’s not a ton of info out there on ferro. Stay safe.

[@chrishuys2671]

this topic has always confused me... THANK YOU SO MUCH for this awesome video! I start my apprenticeship tomorrow morning lol This video was perfect 👌

[@hilineacademy8482]

Awsome Chris. Glad it helps. If you ever have questions that you need answering, ide love to help. Stay safe. Be intentional with ever move you make. 👍

[@fernandovaca7970]

Where did you get your apprenticeship from? Just graduated a year ago and want to be a linemen but have no idea what should be my first steps to getting there. Any pointers?

[@hilineacademy8482]

@@fernandovaca7970 I topped out back in 2006 from the outside line JATC apprenticeship at 1245 in California. Good luck in starting your apprenticeship. It’s a lot of fun. Stay positive and try to always have a smile on your face. Attitude is about 90% of success in everything you’ll do. Stay positive, think before you ask questions, and keep your head down and just work to make yourself better that you were the day before. P.S. always choose the hard job. It will make you better. Stay safe and if you have any questions feel free to reach out. 👍

[@fernandovaca7970]

@@hilineacademy8482 thank you! What are the first steps to becoming an apprentice or lineman?

[@hilineacademy8482]

@@fernandovaca7970 we’ll a lot of guys have started going to line schools. They will teach you how to climb and some trade basics which is great. When you graduate you will still have to get a job on a crew as a ground man and get real experience before you will be ready for an apprenticeship. Also you will need a class A CDL which most contractors will help you get. Becoming an apprentice is no small feat. No one just graduates from line school and walks on as an apprentice. It takes a lot of dedication. You have to show up everyday early and ready to work. People that are ready have great attitudes, their hard working, have a BIG desire to learn, and are an asset to their crew. Join the IBEW, sign the books, and get a ground man job. The union has a great apprenticeship. Look up the hall in your area and call them. They’ll help you. If you have any questions feel free to reach out. Stay safe. 👍

[@TheBVB]

Watched everything on your channel. Hoping for more videos soon!

[@hilineacademy8482]

Thanks for watching. I hope they’re helping. I think this summer we’ll get some more lessons out. Stay safe 👍

[@PanasBhattarai-ol3qo]

good explanation, thanks!

[@richardclucas2824]

Great explanation Cody. How about adding a picture of a pole mounted 3 phase gang operated switch and a picture of the 3 phase transformer open/close switch in your video.

[@hilineacademy8482]

Ya I’ll have to do another one with more pictures of those. Thanks. 👍

[@1995baseballstar]

im only halfway through your video and i just have to say thank you for taking time out of what im guessing is a busy ass life to make this. I consider myself a pretty decent lineman but the book stuff like this has always been tough for me. You completely have made this make sense for me. thank you very much. If you could do some detailed videos trying to teach dipshits like me how to learn the whole vectoring side of transformation that would be amazing. keep up the good work and stay safe at work

[@1995baseballstar]

just looked at your page and realized you have already made a video! will be checking it out for sure lol

[@hilineacademy8482]

Thanks Joeseph. I really appreciate it. If you ever have a question. Don’t hesitate to get ahold of me. If I can help I will. I have an Instagram page also. You can direct message me on there or on messenger. And If it would be better asked over the phone let me know and we’ll make time to talk. Stay safe. 👍

[@kenneth7137]

@@hilineacademy8482 hello Cody if you closed in c phase after energizing a phase would it blow c phase cutout

[@csandoval82]

@@kenneth7137 in a basic ferro situation like what I described in the lesson. Ferro resonance is when you energize both the capacitive source (underground cable) and the inductive load (the transformer coil) at the same time. So it doesn’t matter which phase you close first. When you close the first one, it energizes the delta primary side of the transformer and brings that phase all the way back to the bottom side of the other two cutouts. When you close the second one it will blow because it has no inductive reactance keeping it from a phase to phase fault.

[@kenneth7137]

@@csandoval82 thank you great video

[@MissionFitnessCTC]

Great video. Thanks

[@hilineacademy8482]

Thank you. Anytime. 👍

[@davidjackson4112]

Greetings Cody, Excellent video. Thanks!

[@hilineacademy8482]

Thanks David. I appreciate it. 👍

[@lostbird25]

Great vid once again. Very simple explanation of difficult concepts. You really know your electrical theory, but also, how to explain it in better terms (I think saying “simple terms” makes it seem like we’re idiots and we aren’t!).

[@hilineacademy8482]

lol. Thank you. I appreciate it and yes. We are not idiots. Most of our everyday is way over the heads of a lot of people in the industry. Sometimes the hardest people to convince are our own. lol. Thanks for watching.

[@ARajmadhan]

Super Thanks Bro❤

[@hilineacademy8482]

No prob. Stay safe 👍

[@commonsensecatholics]

Fantastic info and video!! This also happens on OH closed delta banks..would you be able to make some trouble shooting vids..with various scenarios? wire down & back feed issues etc..transformer troubleshooting...what to look for when going to call where lateral fuses are blown etc...I'm sure you can implement more, but just wanted to throw that out there.

[@hilineacademy8482]

Thanks for the encouragement. I would like to do a lot more videos on trouble shooting and backfeed in the future. I have to build all of the scenarios in my back yard using the simulator and it takes a ton of time to set up. Plus I probably need to build some more tools to be able to put a good lesson together. But I’m working on it. Lol. 😮‍💨👍stay safe.

[@MichaelBoamah-dj1ys]

good teacher, you are the best ❤❤

[@hilineacademy8482]

lol. Thanks. I appreciate it.

[@danmiller2177]

Thanks...👍👍👍👍👍

[@tommywatterson5276]

Good explanation and very understandable

[@hilineacademy8482]

Thankyou. 👍

[@jasonleary6717]

Great Video Cody

[@hilineacademy8482]

Thanks Jason. It was a tough one. Lol

[@jasonleary6717]

@@hilineacademy8482 That subject matter right there is always a tough one for sure.

[@scooter7371]

I love how you teach, although I would recommend changing the "I^R" representing your (Inductive Reactance) to "XL" which is typically how you see it. Seeing it your way was confusing until you said something. BUT GREAT VIDEOS SO FAR!

[@hilineacademy8482]

Lol. Yes sir. Thankyou. I was trying to keep it simple. Also reactance is measured in farrads but I said resistance. Lol. I’m trying not to throw a ton of stuff at them all at once. Please keep the feedback coming. Stay safe.

[@lokiva8540]

​@@hilineacademy8482No, capacitance is measured in Farads (often milli, micro, or pico). Reactance is measured in ohms, but with symbol conventions to indicate capacitive or inductive, based on the lead or lag relationship of current and voltage. Z (impedance) is the vector sum of R and X(C or L), which makes misuse of standard symbols for resistance and current horribly misleading to anyone trying to seriously understand basics of reactive circuits.

[@D.Hozzie]

Excellent! Where or how does the transformer impedance rating come into play? Just secondary?

[@hilineacademy8482]

Great question! So when we look at impedance by definition. The definition reads “The total opposition to current flow in an AC circuit.” The word “Total” is the key. Impedance is made up of both the resistance and the reactance of a circuit, and when we add those two things together they give us the impedance of the circuit. Now in transformers they will give us an impedance in the form of a percentage. For example. Pri input: 7200/12470Y Sec output: 120/240 Impedance: 1.7% What this impedance percentage means is that when our transformer is at 100% load, the secondary voltage will drop 1.7%. The reason that we need to know that is because depending on whether we are building a transformer bank or We are installing a single phase service we need to know what our customer will see in voltage when our can is fully loaded. If we are at the end of our primary circuit our primary might be low. If we are right outside the sub our primary voltage might be high. Stay safe 👍

[@eluv201]

👍👍

[@bdcfu]

Awesome video. So am I correct in saying that it will only be an issue when you have a three phase delta transformer and a relatively long run feeding it? How long of a distance would you have to start to be concerned about this condition? Also, is it an issue with both Y and Delta primary feeds?

[@hilineacademy8482]

You mostly find ferro when you have a delta primary connection but when you have a wye primary connection and it’s an extremely long run you can run into it too. It’s a hard condition to predict. There’s a lot of factors that play into it. Primary voltage, KvA, frequency, wire size…..and we don’t have a lot of ways to measure that accurately enough to say it will be present or not. That’s why we assume it going to be a problem in almost every instance. Just follow the rules to mitigate it and you won’t have a problem. Stay safe. 👍

[@marshallstephens7356]

Thank you for sharing this. Clear diagrams and excellent presentation.

[@hilineacademy8482]

Any time. 👍

[@owaiselectrical]

If the Inductive reactance and capacitive reactance cancel each other out, why the transformer is not damaged. Why the fuse is blown?

[@Birol731]

Thank you very much for this interesting lecture 🙏 What about, if the current is despite the resonance less, then it will not burn, right ?

[@hilineacademy8482]

I think I understand your question. But if I’m off please let me know. So if the magnetic reflection, or resonance of the transformer is not enough to counter the inductance of the coil, you should be fine. It’s actually a difficult thing to guess at because depending on load of the transformer and the frequency of the source primary voltage at the time your opening or closing it, ferro resonance might be a problem at one part of the day and not be a problem at another. So we always just treat it like it’s going to be a problem we have to protect ourselves against. Stay safe 👍

[@thirdeyespidysensiz3913]

At our utility we are told to close at least two switches at the same time, Ive been a linemen for along time and haven't had a blow up yet doing this on delta, this seems to work, i guess reducing Capacitance preventing this?? or maybe just lucky... 😂

[@Birol731]

It occurs if the core is made of ferrite or a ferromagnetic material, if a different core material is used, ferroresonance will not happen, so, which role does the ferromagnetic material have, what happens here in the molecular structure of the core material ?

[@hilineacademy8482]

We’ll all transformer cores are made of ferrite or magnetic material. Most are made of silicon steel and a lot of manufacturers are now using amorphous material which is and even more efficient material than silicon steel. I’m sure there are differences when quantifying whether ferro resonance will be present but we just treat all situations like it’s a problem we will have to deal with. 👍

[@Birol731]

@@hilineacademy8482 Thank you very much for your answer. I will check the list for the ferromagnetic core materials.

[@andrewwebster6221]

can Ferroresonance occur with an oh wye closed delta bank feeding oh services?

[@hilineacademy8482]

That’s an interesting question. I’m assuming that it’s a three pot bank wye primary, closed delta secondary. With these banks most places float the primary neutral connection. When we operate the cutouts (open/close), we have to tie down the primary neutral. If you don’t tie it down, and open one of the cutouts for example, you impose a phase to phase voltage across the other two transformers that are still energized. This is often called ferroresonance. But it’s not. Ferroresonance is when you are energizing or denergizing an inductive load along with a capacitive source. It’s the action of energizing or denergizing both the underground cable and the transformer coil at the same time. Sorry I haven’t got back to you sooner. Ive been hunting lol. Please get back with me and let me know if I’ve answered your question. Stay safe.

[@robertwaldrop3100]

Yes!! We normally put a fourth cut-out . The fourth cutout ties the pot down ( as you float normally a wye/delta) Throw the fourth cut-out in FIRST! then throw your other pots in and then pull the fourth cut out barrel.. The system I worked on before this one didn't ever use them ( rarely) so I've never had one blow due to a charge. The CO-OP I'm on now installs them on every 120/240y bank

[@LaneMichaelMusic]

Hiline academy. Is it possible we could get in contact about this issue? I work for a utility on Virginia and we have this issue in an area and it is so frustrating to deal with. I'd love to chat with you to see how you think we could resolve it

[@hilineacademy8482]

Sure. My email is [e-mail]

[@treytillman2444]

Can you do a video on a corner grounded bank?

[@hilineacademy8482]

I’ll add that to the list. Lol. That’s a good lesson to do. Do you have any questions about it that I can help you with right now?

[@fernandovaca7970]

Is there any linemen books I can buy?

[@hilineacademy8482]

I don’t have any books out yet. Hopefully in the future I’ll write some. In the man while. “Transformation for line workers” is a pretty good book. Another good book is the yellow transformer book from the JATC.

[@Birol731]

If Ferroresonance is a phenomenon on the molecular level of the material, can you tell us what is happening and how can we find this intrinsic resonance frequency ? If this point is achieved jumps the current and potential suddenly ?

[@hilineacademy8482]

That’s a good question. Without putting some pretty sophisticated metering devices on the line, and having some type of baseline readings on the specific transformer your working on, it would be very hard and impractical to rely on. In the field lineman just use some general rules and experience to determine whether it’s going to be an issue.

[@Birol731]

@@hilineacademy8482Thank you very much for your answer. I will design an experiment and will connect the transformer to a function generator, by increasing the frequency step by step, I hope to achieve the resonant frequency (ferroresonance) of the transformer in this way. The output (secondary coil) will be connected to an oscilloscope, by this way I hope to see the sudden increase in the potential of the resistor. Would this be a possibility ?

[@csandoval82]

@@Birol731yes I believe it will. Frequency and load of the transformer have a direct correlation with the phenomenon. I’ve never seen the math in it but I’m very interested to see what your results will be. Keep it up and let me know. 👍

[@Birol731]

@@csandoval82 Okay, once I have done the experiment I will inform you 👍

[@csandoval82]

@@Birol731 Awsome. Thankyou. Where are you working?

[@StoneStraiff]

You should do a video on URD Transformers.

[@hilineacademy8482]

Lol. URD transformers is definitely on the list. I just need to gain some access to some so I can show hands on examples for the lessons.

[@kenneth7137]

@@hilineacademy8482is there anyway I can contact you directly

[@tedlahm5740]

The drawing of the Delta is actually 3 (three) different transformers? physically.

[@hilineacademy8482]

Yes sir. For a better explanation. Watch the lesson I did on vectoring. 👍

[@douglaswhalen3854]

Cody, are you IBEW?

[@hilineacademy8482]

Yes sir. I apprenticed through outside line 1245 back in Cali. Back when 1245 had all of outside line. I moved back to Az and I’m currently working out of local 266.

[@douglaswhalen3854]

@@hilineacademy8482 Local 103 here. I use your video to help my classes with chapter-4 in the textbook. Great work, thanks.

[@hilineacademy8482]

@@douglaswhalen3854 that’s Awsome. Let me know if there’s anything specific you’d like a video lesson on. Ide love to fill the need. 👍

[@alfreddemarbiex6078]

SRP 🖐️…great job in explaining things…for years have had ferróresonance explained as just some phenomena that happens 🤣. Keep up the good work👍🏽

[@justindelecki]

Nice video. I’ve been told by the old timers a way to avoid this situation is to use a wye-grounded primary transformer generally on primary voltages above 15kV class. But looking at your diagrams I’m not sure how that would solve this. This is one of the reasons why most utility substations use wye-grounded primaries I’ve been told. I have myself seen an issue where a 34.5kV delta primary transformer had it lightning arrestors blown during construction commissioning where single phasing occurred on the primary. Any idea of why wye-grounded primaries solve this? To be honest, I’m not sure, just been told this is the way. Thanks for your help and insight. Trying to gain knowledge here. Thank you.

[@denverbraughler3948]

Did you think it through or try to draw one? It’s pretty obvious that with a grounded-center wye, no phase connects to any other. (Watch the video for where phase A voltage comes back to the switches for phases B and C. With a grounded wye, each phase connects through the transformer coil directly to ground.)

[@dudewithpen]

So unity is good?

[@hilineacademy8482]

Well in order for the transformer to Not blow up when we energize it, it needs the Inductive reactance in the transformer coil to limit the current flow. But when we energize both the capacitive feed (underground cable) and the inductive load (transformer coil) at the same time, they get rid of each other and bring the circuit to unity, which is why the cutouts blow. So we need an inductive circuit. Please let me know if I answered your question. Stay safe 👍

[@lokiva8540]

I would blacklist hiring this so-called instructor, as I and R are standard symbols for current and resistance, whereas X sub C or L are capacitive and inductive reactance, and exist as vector sums with R to form Z (impedance). Cult indoctrinating misinformation is never a good practice.

[@katiesjoyfullife]

Are you married? I find your intelligence very attractive 😉😉😘

[@hilineacademy8482]

I am married to a stone cold fox. But she’s an old and battle axe, and let me tell ya. She likes to wield it. So I won’t tell her what you said. Thanks and I’ll keep this between us Ps. Your not too bad yourself. 😘

[@joshhoffman9404]

@@hilineacademy8482 couple of highschoolers....

[@richardboran749]

Where’s the swag ? Quality hats made in USA ?? With the Arizona skeleton lineman up in the cactus and all that complimentary “Dry Heat..?” What..? No Arizona skeleton lineman T -Shirts wearing the cowboy hat ..? What kind of business are you running here Ghost Rider..??

[@hilineacademy8482]

Lol. I hear ya. Down the road a ways we’ll be coming out with all sorts of stuff. We’re just taking small steps right now. Thanks Richard. 👍

[@ovidius2000]

👍👍.NowTheQuestionIsHowTheSecondaryOfATransformerWhenLoadedIncresesTheCurentInThePrimary?This,BecauseWeSeeThatPrimaryHasLittleAmperageWhenNoLoad. Now a new confusion arises:Iron"Losses",MeansFreeHeating?

[@hilineacademy8482]

I think I understand your question. In regards to the the primary and secondary current, the current relationship between primary and secondary is based on the ratio of the transformer. For instance if it’s a 30:1 ratio transformer, meaning a 7200 volt primary input And a 120/240 volt output, the ratio is found by dividing the primary input by the highest secondary output. So 7200/240 = 30. Or 30:1 ratio Now this ratio determines a lot of things like the input/output voltages, the current and the turns ratio. In regards to the current, if the secondary is drawing 30 amps of current, the primary will read 1 amp on the primary. Now, even with no load on the secondary you will still read a little current on the primary coil. This is called the No Load Loss, or NLL. The primary is hooked up either phase to phase or phase to neutral, and the transformer requires current flow to create the magnetic field in order to create the secondary potential. So in actuality the primary current will read the 1 amp from the 30 amps being on the secondary and the NLL just from creating the secondary voltage in the first place. I hope this helps. Stay safe 👍