Substation

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Racquetballfan

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hi all -

If i have 138KV lines coming into a facility and i need 4160V to run eqpt, do i need a substation or do i just need some transformers to step voltage down to 4160 and provide it to the equipment? Is it that simple or will there have to be meters, switch gears etc installed as 138KV lines are not owned by us.
Also - if i have an extra transformer (similar) and wire it up in reverse, if i feed it 4160V will i get 138KV volts taht i can put back on poles and transmit?

thanks for your help!! :)
 
I think Racquetball fan is just trying to get an understanding of the big picture,,,,,,,,,,,,,,,yes you need all of the above and they all have their unique uses and requirements.

Yes in theory on you transformer question but don't do that or somebody will probably get killed upstream.

I would suggest some research on your part,there is a lot to learn in the your new field of endeavor.

I'm not an Engr by education or an Electrician by trade. I make my living by trying to help both with so called design concepts.

Its a team effort,,,,,,,,,,

dick
 
With a 138 kv highside , you will need a substation . Depending on the configuration , you may need some high voltage circuit breakers so that the transmission line will be properly protected . This will probably be done by the power company , but the customer could have some expense there too .
 
zog said:
It is not that simple, sorry but if you are asking these questions you are in way over your head.
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Zog, if you have nothing helpful to add then please do not bother.

Here you have someone that wants to learn and you give him the 'your over you head' response.

So what have you accomplished? Do you think because you told him he is over his head he is going to change his course?

If your not comfortable with helping him then fine don't, but there is no need to be arrogant about it.
 
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I vote for the substation (letting the utility provide the power you need). The upfront consts may be undesirable, but the long term costs may be cheaper. At any rate, I think you would need to to a detailed cost analysis to determine what is in your (plant's) best interest.
 
Hi Racketball Fan,

A substation is a step down transformer with the only difference being the owner of the transformer. Most large manufacturing facilities own their "substation" transformers, smaller facilities rent the transformer from the utility company after paying for the initial installation. The biggest difference between the two being maintenance and long vs short term costs.

Also, voltages do not kill people, amperes (current) does. What kind of amperes are you dealing with?
 
dicklaxt said:
I think Racquetball fan is just trying to get an understanding of the big picture,,,,,,,,,,,,,,,yes you need all of the above and they all have their unique uses and requirements.

Yes in theory on you transformer question but don't do that or somebody will probably get killed upstream.
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Any time power is put back onto the grid, there has to be some form of coordination. For small power producers, it's usually in the form of anti-islanding -- the output back to the grid senses when the grid is lost and disconnects within 6 cycles, as I recall. For larger power producers, such as combined cycle generation (what I'd guess he is talking about) where there is excess electric power at times, he'd have to coordinate with the next substation upstream. He'd get a signal to cut power back to the grid and he'd have a certain amount of time to respond. He could still supply the 4160v for his own use, but the 138kv output to the grid has to be disconnected.
 
iwire said:
Zog, if you have nothing helpful to add then please do not bother.

Here you have someone that wants to learn and you give him the 'your over you head' response.

So what have you accomplished? Do you think because you told him he is over his head he is going to change his course?

If your not comfortable with helping him then fine don't, but there is no need to be arrogant about it.
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Are you serious, someone comes in with a DIY question about a bathroom fan and you guys refuse to answer and refer to the forum rules of no DIY questions. This is a DIY question for 138kV substation. Heck, I dont even think there is anyone in this forum qualified to answer that question, not many anyways.
 
zog said:
Are you serious,
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I am entirely serious, if you don't wish to help then just don't answer. It is the same request I have been making for quite awhile.

iwire said:
To all forum members, I am formally requesting that you no longer publicly question new members qualifications for posting here.

Keep in mind that all new member posts have already been approved by a forum moderator before they show up on the forum.

If you feel a new member is over their head please exercise one of two options.

1) Notify one of the Moderators, I suggest you send a PM to one of us with a description of the problem you see with a post. We will gladly discuss it with you.

2) Do nothing, ignore the post and move on.

The reasons for this should be self evident, we are going to chase away new members if they feel they have to justify their qualifications with the entire membership at large.

Not to mention many times it is just plain rude.

Bob
2007 Chief Moderator Mike Holt Forum
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That is a sticky post in the front of the NEC forum
 
Racquetballfan said:
hi all -

If i have 138KV lines coming into a facility and i need 4160V to run eqpt, do i need a substation or do i just need some transformers to step voltage down to 4160 and provide it to the equipment? Is it that simple or will there have to be meters, switch gears etc installed as 138KV lines are not owned by us.
Also - if i have an extra transformer (similar) and wire it up in reverse, if i feed it 4160V will i get 138KV volts taht i can put back on poles and transmit?

thanks for your help!! :)
Click to expand...

May I suggest you ask your questions over in this forum, you will find many qualified power engineers to help you.

http://www.eng-tips.com/threadminder.cfm?pid=238

This is a forum based around the NEC and your question is a little outside the scope (I ride the border of outside the scope of this forum every day)
 
zog said:
May I suggest you ask your questions over in this forum, you will find many qualified power engineers to help you.

http://www.eng-tips.com/threadminder.cfm?pid=238
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Cool how nice.

This is a forum based around the NEC and your question is a little outside the scope (I ride the border of outside the scope of this forum every day)
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If it's customer owned equipment the NEC applies even if it does not do a great job at it.
 
crossman said:
There is no doubt that the best course of action is to consult with the POCO and hire an engineering firm who is familiar with high voltage installations.
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Sounds like great and safe advice. :cool:
 
zog said:
Are you serious, someone comes in with a DIY question about a bathroom fan and you guys refuse to answer and refer to the forum rules of no DIY questions. This is a DIY question for 138kV substation. Heck, I dont even think there is anyone in this forum qualified to answer that question, not many anyways.
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DIY questions about high voltage substations are just a whole lot more fun than bathroom fans. Besides, they also provide a much bigger boom. Don't forget to send us back some pictures.
 
George Stolz said:
And I find it a whole lot less plausible that it will be erected without competent people behind it.
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That was a point I metioned in a PM to another member about this thread.

While we know a person asking about bath fan is going to move ahead on their own I find it very implausible that 138kv equipment is going to be purchased, installed and energized without at least a few qualified people being involved.

Inspection departments, power companies, other engineers, the company providing the equipment, the people installing the equipment.

I really do not see that Racquetballfan is planing to do all this in some sort of vacuum.
 
The OP asked about backfeeding a xfmr with 4160 and getting 138KV so he could run it on poles. In my head, I was imagining the OP out there with 10 laborers haphazardly stringing some THWN conductors on some wood poles and energizing that sucker!

:cool:
 
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