Hope all went well with the test. Im going for my 4th year/ inter provincial in like 5 weeks. Forgot everything from the year previous, this guy is a life saver!
Absolute fantastic explanation and drawing. I usually rate anything either good, very good, or wonderful. For me to use fantastic as a rating is truly exemplary. A thank you to you.
Only small suggestion would be to put that Delta Wye drawing back down at the bottom of the screen. A visual reminder of what we are looking at. Thank you.
Can you please tell me how to calculate, the fuses in the primary for a transformer 600 volts, 3 phases, 75 KVA? Primary Delta and secondary Why. Thanks.
I really learnt so many basic concepts from your videos, Thank you for making this so easy to learn i got one question for you Suppose if i have to design one transformer and i have to select WIRE SIZE on primary side so what should i consider for Amps by Phase current or Line current( if primary is Delta)
Thank you for watching and for your kind words! For your question, with a three phase delta connection we would use the line current for calculation purposes. This can be derived from the KVA rating divided by (Line Voltage x √3). At this point you would multiply by 125% to determine the calculated load of the required conductor to size (respecting termination temperatures). Hopefully this answers the question for you!
@@schulerruler Thank you for your clarification 😊 and i really don't want to bother you again but i have one more question for you because i tried everywhere to find the solution but couldn't find it. Question:- Suppose To design a transformer with 5KVA and Primary has to be 380/240 Delta and secondary 208 Volt Delta. P.S:- Primary is just single wind of 380 volts with 240 volts tap on the same wind (No other winding) which both gives 208 volt in secondary. So is this kind of design doable or not doable? i have attached the link for question below:- ru-vid.comqsny1uzBgI4?si=sDx9LqocwwGw-crt
It's actually just tempered glass, with LED strip lighting around it. Then the camera inverts the image so it doesn't appear backwards. I'm not actually left handed haha.
Hey man I just did my masters exam. 2 questions were asking for the minimum interrupting current of a tx they gave tx size and voltage also impedance . Do you know how to calculate that .? Thx
I have a configuration where my service is 120/240v 3 phase delta coming in (grid). I will be hooking up a generator to this and synchronizing. I can configure my generator as wye or delta and adjust the voltage to match grid. I am thinking of configuring the generator in delta and tying it to the grid. What I am concerned about is the neutral. On the service side the neutral is hooked up to ground. On the generator side I don't need a neutral even though I can center tap one of the legs. Do you think I should forget about the neutral on the generator side completely? Will it pose a problem if I center tap the appropriate leg and hook up the neutrals? thanks
Excellent video. I am a teacher for the IBEW JATC in Rochester NY. We recently went virtual and I would love to use the white board system you have. Could you please tell me how it works? Thank you.
Hi Mark, sorry for the delayed response. This system is called a light board. It has led strip lights around the outside of a short of tempered glass, and the camera inverts the image as we write on the back of the glass.
Good morning , for the 3 transformers installation in Delta to have the high leg, please, can you tell me if all 3 transformers must have same Power output ?
What if you change primary delta to wye? Voltage between H1-H2, H2-H3 and H3-H1 would be 600, voltage between H1-N, H2-N and H3-N would be 346. On secondary end L1-N voltage of 69 and between phases of 120V, correct? The transformer is 1:5 - as in its original form it goes from 600V to 120V, correct?
Yes, by changing to eye on the primary your phase voltage applied to each coil would be reduced by root 3, inducing root 3 less phase voltage on the secondary as well. Meaning now you would have a line to line of 120 on the secondary as you've stated!
Good day. Love your videos. I just want to find out as I am still studying and learning it all. I have a 3phase transformer. 600V 75KVA 72.2A primary. Which will be 75000/600√3 = 72.2A. Then I have a 208/120V 208A Secondary. And to get that it is 75000/208√3 = 208A. Why is this like this and not 75000/120? Thank you. Its a Three phase General purpose transformer. Thank you
Dividing 75000 by 120 would give you the phase current in this system, which in Wye is 1.732 x smaller than line current. So you incorporate the x 1.732 into the equation while doing it instead.
If the line and phase currents in a wye configuration are equal, why can't you divide the secondary total VA (150000) by the secondary line voltage (208) to get the secondary current value? Shouldn't both equations give you the same current value? Thanks!
Thanks for watching and commenting. Check out my video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-aFZyhiCnicQ.html It walks through how the three phase power formula is derived. From there we establish the transposed formula for individual line current : line current=total va÷(line voltage × √3)
What you're doing by connecting them like this (delta) is increasing the deliverable capacity. As long as transformers are well matched (impedance, %iz, voltage regulation) then no unwanted circulating currents will be present, which would cause the excessive heating condition.
When talking about full load amps for single phase transformers or a 3 phase transformer we express what each line conductor can deliver. We never add all the phase currents up for total output.
Adding up the apparent power of each phase (when balanced) will determine total output, or ELine x ILine x √3. Definitely do not add up the phase currents.
Depending on the secondary side of your transformer (single winding 220v, or multiwinding with 110/220 available) you would still apply the same methods. A delta secondary would still yield same phase/line voltages, while a wye connected secondary would yield a 1.732x higher line voltage than phase voltage.
