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I am an Alderman with a small Missouri city. Our largest employer in town has decided to expand. This expansion is going to require that the City double the size of our waste water treatment facility. During the planning phase for this expansion, our electric provider came to us and informed us that the 3 phase power to our sewer plant was actually "imitation" 3 phase or "jack leg", and had been for the past 50 years...since they are no longer "supporting" this type of transmission line, they are requiring the City to upgrade to true 3 phase, at a cost of almost 300,000 dollars...

My question is two fold...First, we have always had a problem with burning up motors at the sewer plant (this was written off due to lightning strikes). Could our problem be with the imitation 3 phase?


Also, I have been told that single phase electricity is more expensive than 3 phase. Is this true?...and does that relate to "jack leg" 3 phase?


..any comments and guidance is greatly appreciated...
 

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I think you need to discuss this with a local electrical engineer, or at least a competent electrician.

This site is intended for people in the trade, and it's against forum rules to get too involved with this (no disrespect intended).

You will have more questions as your discovery goes on. Local professional help is the way to go.
 

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I am an Alderman with a small Missouri city. Our largest employer in town has decided to expand. This expansion is going to require that the City double the size of our waste water treatment facility. During the planning phase for this expansion, our electric provider came to us and informed us that the 3 phase power to our sewer plant was actually "imitation" 3 phase or "jack leg", and had been for the past 50 years...since they are no longer "supporting" this type of transmission line, they are requiring the City to upgrade to true 3 phase, at a cost of almost 300,000 dollars...

My question is two fold...First, we have always had a problem with burning up motors at the sewer plant (this was written off due to lightning strikes). Could our problem be with the imitation 3 phase?


Also, I have been told that single phase electricity is more expensive than 3 phase. Is this true?...and does that relate to "jack leg" 3 phase?


..any comments and guidance is greatly appreciated...
They might be referring to an open delta system.
This is fine for small installations but kind of has a practical threshold.
I suspect that they want to bring in a third phase and add another transformer.

Lots of times they install new equipment and calculated the ROI on it and that determines the price you have to pay.
I suspect that your new demand is giving them an excuse to upgrade a substantial part of their distribution in your area and they want to do it out of your deep municipal pockets.

Someone please prove be wrong here. :)
 

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They might be referring to an open delta system.
This is fine for small installations but kind of has a practical threshold.
I suspect that they want to bring in a third phase and add another transformer.

Lots of times they install new equipment and calculated the ROI on it and that determines the price you have to pay.
I suspect that your new demand is giving them an excuse to upgrade a substantial part of their distribution in your area and they want to do it out of your deep municipal pockets.

Someone please prove be wrong here. :)
I think you nailed it.
 

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I agree with the others. As I'm sure you are aware, you need to proceed with caution.

1) discovery phase:
A) find out exactly what the existing system is (and is not), preferably with engineering help, so that you have a "basis point", and can have the engineer not only check the utility company's "facts", but also develop plan(s) of action and alternatives as it goes. (added: in either case I strongly recommend having the city's chief electrical inspector help out, if that is possible).
B) find out exactly what needs to be upgraded.
I) what needs to be upgraded at the plant
II) what needs to be upgraded at the point of service
III) what distribution upgrades the utility company is trying to charge you for.

2) develop plans of action, not limited to merely the work that needs to be done, but also using the municipality's leverage (whatever that may be) in convincing the utility that the distribution upgrade costs should be mitigated. Obviously, the last page might be a necessary increase in public utility fees or special assessment, but that should be the last resort. You may very well find during your investigation that the distribution has either already been paid for in some prior iteration, or that the public utility commission has mandated specific requirements for distribution that make these fees unwarranted.

3) (your domain) get public approval, etc, so you can get reelected :laughing:
 

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In addition to what others have said, talk to the largest employer and see if they can share in the increased costs. Of course this may be a political impossibility.
 

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This is more the realm of the POCO and engineers, not for the city council.

Not exactly a DIY question, but beyond the scope of the forum.
 
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