Generator Power Distribution

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faresos

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Hello every one..

I'm working on a project that is an existing five story office building, this building is backed up by two 1000KW generator (paralleled), each of those generator will carry 50% of the load. The owner wants to have a seperate Generator to support an entire new floor(existing floor will be remodeled) with1250KW generator. Then the owner requested if we can interface the new generator with the other two existing generators incase the new generator didn't run. In another word, how we can obtain power from the existing generator to supply the new floor incase the new one faild? Thanks in advance for any thoughts...
 
Are these generators suppling Article 700 emergency loads or Article 702 Optional standby loads or both?

It sounds like a it could get very complicated if these supply emergency loads.
 
I think we might need some more information:

--What's the square footage of the new floor? A 1250kW unit seems oversized for additional floor.
--Are the (2) existing generators backing up 100% of the building load?
--Has anyone done a load study for the (2) existing generators? You might not need another.
--Are there Critical applications that MUST remain powered? Any load shed applications?

Like Iwire has said, it could get very complicated depending on what emergency loads are being powered.
 
Anything is possible given the right amount of $$.

Your difficulty will be in splitting, or isolating the loads you want to run. As an alternative, you may want to consider 2 smaller units instead of one 1250kW. That way you could run half the loads if one fails.
 
Forgetting about the needed KW and any issues with Article 700, the actual mechanics of this are not that bad.

Install the new generator with an ATS for it.

Install another ATS onto the paralleled generators.

Have the new generators ATS supply the added ATS on the existing generators.

Program a longer start delay into the new ATS at the existing generator.

Normal utility both ATS remain in utility position.

Utility failure will immediately start the new gen set it's ATS will transfer, the added ATS at the existing gen sets will ignore this short power outrage do to the added delay.

If this new gen set fails the added ATS at the existing gen sets will see the power failure and pick up the load.
 
Thank you all for your reply...

Bob, I had the same idea of having a new ATS for the existing generators down stream of the new generator ATS but I wasn't sure if it can be done that way. Now the question, when we add the new ATS for the existing GEN set; Do we have to add a circuit breaker at the stand-by distribution board and run a feeder to the new ATS (for the existing gen sets) or we could come staright from the paralleling switch gear (which I'm not sure how).

Thank you again..
 
Their are multiple ways to do what you are wanting to do, however it is dependent on the way the system is configured. Without a one-line it would not be prudent to propose a solution.

Things that need to be considerd:

How will you load shed if the new EG fails and the other two are already operating?

If you want to maintain partial loading of each floor upon failure of one unit, how will the loads be segregated to it?

Is it possible to lose power to the new floor without interrupting service the the other floors?

How do you invision controls for sharing the load between the new and existing generators?

How much room is available for switchgear.

Simply adding a couple ATS switches doesn't seem to cover all the potential issues.
 
kingpb said:
Simply adding a couple ATS switches doesn't seem to cover all the potential issues.
Click to expand...

That is probably why I said "Forgetting about the needed KW and any issues with Article 700" ;)

'Doing it' is the easy part, getting there may be simple or hard.

We both agree more info is needed, but would that not be obvious to an electrical engineer as the opening poster is listed as?
 
iwire said:
We both agree more info is needed, but would that not be obvious to an electrical engineer as the opening poster is listed as?
Click to expand...

I do not know the poster personnally so I cannot vouch for his abilities.

But in my dealings with other "engineers" I have learned, we are not all created equal! ;)

Matter of fact, to this day one of the best "engineers" I have ever known, was self taught, passed the PE, and was very respected. Very few degreed engineers could match his knowledge on power systems.:)
 
kingpb said:
I do not know the poster personnally so I cannot vouch for his abilities.

But in my dealings with other "engineers" I have learned, we are not all created equal! ;)

Matter of fact, to this day one of the best "engineers" I have ever known, was self taught, passed the PE, and was very respected. Very few degreed engineers could match his knowledge on power systems.:)
Click to expand...


Exactly how does a "self taught" person get a PE? The normal route is through a ABET certified school, and then 4 years of experience under another PE.

I am pretty sure that (in this state anyway) anyone who lacks either of those is SOL. No if's, and's, or but's about it.
 
Steve,

At one time, albeit many moons ago, you could work under a registered engineer for, if I remember correctly, something like 12 years, and take the PE. I believe this is no longer allowed, in any state.
 
kingpb said:
Steve,

At one time, albeit many moons ago, you could work under a registered engineer for, if I remember correctly, something like 12 years, and take the PE. I believe this is no longer allowed, in any state.
Click to expand...


I guess I am just trying to point out that he must not of been totally self educated. He had to learn something from working under another PE for 12 years, even if he didn't have a traditional education.

Steve
 
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