Given two Wye-Delta transformers with unequal equivalent impedance, it is my understanding that a circulating current will flow between them. References I've say this is a zero-sequence current, however I have trouble understanding how this current can circulate given the Delta side has no neutral conductor. Could someone help me shed light on this?
I want to express the secondary voltages of a Wye(pri)Delta(sec) transformer in terms of the primary side voltages.
https://i.imgur.com/UxLU1yd.jpg
The transformer is 1:n The primary line to ground voltages are: Ea Eb Ec and the secondary side line to ground voltages are Ea' Eb' Ec'
I want to expressions for Ea' Eb' Ec' in terms of Ea Eb Ec i.e Ea'(Ea,Eb,Ec) Eb'(Ea,Eb,Ec) Ec'(Ea,Eb,Ec)
What I could write was the following relationships: https://i.imgur.com/mIxZYCq.jpg
But the terms cancel out and it doesn't work.
What am I doing wrong here?
Everything I've found so far through searching says there is going to be a 30 degree phase shift, and is explained using vectors. While I was going through some one-lines at work, I see that we have some delta/wye 0 degree transformers. I don't understand how this is possible, and no one at work can give me any insight how that's possible.
I have a 480Y/277V (Wye) supply source (from Utility/Generator). Why is it typically to install Delta-Wye Transformers vs Wye-Wye Transformers to further step down low voltage?
May someone explain to me why you can connect 3 hots of a Wye source to the primary side of a Delta-Wye Transformer?
What difference does it make if you don't connect a neutral? Got a textbook that shows it connected, and another textbook that shows it not connected. No information is given to explain the difference. (I guess you also have to take into consideration if you have a 4 wire wye or 3 wire delta power source)
The box at an industrial site was labeled as 480 WYE, but was actually 480 Delta. There is 480V WYE equipment was purchased, but the project manager says that we're going to get an entirely different unit. I don't understand why we can't use a transformer and wire it up. It's 20KVA, is there any reason besides cost?
I have a graph i need to fill out for homework -it's a hypothetical transformer setup. Here's the question...
So it's a dual-winding Wye-to-Delta step-down transformer, with a source of 2,400v and I need to get 480v on the low-side.
I've worked the problem from both ends, but i don't see how i can get exactly 480v. Starting from the Wye side, the source (2400v) get's stepped down by root3 to the phase, so you get 1386v (or so) on the primary phase... and the secondary is a delta, so the phase voltage will be 480. Assuming it's a 10:1 transformer, the only way i can get lower voltages transforming across is if i connect it in a Buck format. But then it wouldn't be exactly 480v....
Sorry if I'm not 100% clear, but any help will be appreciated!
Hello,
My facility is replacing a 40hp dual voltage motor. The existing is a 9 lead connected in wye. The new one is 12 lead and its wiring diagram indicates delta connections. However, one of the employees suggested that it be connected in wye. It's being fed 480V, and is controlled by a VFD.
Anyone know of any reason not to do this?
Thanks.
Edit: update -- connected it high voltage delta. Thank you, everyone, for your opinions and advice.
I know this might sound silly but it actually happen which has sparked my curiosity.
There was a piece of equipment that we had to install and it was overlooked that it required 3 phases and neutral but our plant system is just 3 phases, no neutral. Our electrician was able to wire it up anyways with just 3 phases and utilizing the grounding of the equipment for the neutral. How would this work? The equipment was able to turn on but when attempting the output it started to blow fuses.
Hello everyone. For the first "real" homework, the last problem involves calculating the power-draw of a triangular element. Is there a way to reduce the element, despite there being a voltage source? I'm also wondering if maybe the problem can be reduced with Delta-Wye, but in a different location (redrawing the circuit might help to see, if such a possibility exists)
Turns out that redrawing the circuit helped immensely. I was confused that the component "D" is actually mirrored to it's actual orientation on the circuit.
http://imgur.com/Sz8kyn0
Please don't post solutions, but if you have ideas or insights you can share I would greatly appreciate it.
I am getting new service dropped into my facility. I asked for 480 3 wire (delta) and through miscommunication or my own negligence I am getting 480/277.
I have a MCC that is 480 3 wire. Can I terminate the neutral in the box and use the 480 MCC in my system?
Is there a means to adding a neutral in the MCC and using it as 480/277wye?
If the answer is a "no" does anyone have a 800 amp MCC 480/277 wye with a few bucket brakers, as well as an 800 amp fused disconnect for outdoor installations?
Any help would be greatly appreciated.
Just wondering what conditions have to be met in order to use them. Thanks
I am working at a client site and they have a 600-480V WYE autotransformer. I am seeing excessive voltage drops (around 7-8%) when this transformer is even lightly loaded (25kw of load on a 112kva transformer). What could cause this? Unloaded output is 505V, loaded is around 465V
Wanted to know what is the proper way to de-energize this bank using the firecracker. How do you connect it.
I've got an inspector concerned about a Wye/Wye solar transformer. It's a 208V service with 480V solar inverters. His concern is with both sides of transformer having connections to neutral and providing a parallel path for fault current. I can't find anything about the proper grounding and bonding of a Wye/Wye transformer to satisfy this inspector. Can anyone help?
Is there a nice visual tool that anyone is aware of that I can use to model the phasors in a 3phase system?
For example: I'd like to see the phasors of a wye-delta transformer, or a wye-wye transformer, and see how the phases relate to each other.
Bonus points if I can simulate a ground fault....
I got a quote from Larson Electronics for $4000 and I see used ones in mint condition on craigslist in Vancouver for $1000. Any ideas where else to look?
Can someone explain the difference in the wye and delta connected, 3 and 4 wire voltages and how to tell the difference between the two in the field? Thanks in advance.
