# Power Blues



## brian john (Mar 11, 2007)

Are these units paralleled or stand alone units on separate ATS's.

Have you monitored current, voltage and harmonics? If paralleled are the units matched same generator? same voltage regulators and governors.


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## Southeast Power (Jan 18, 2009)

I would assume they are paralleled even though they are small and low voltage. 
Is this a recent development? 
How much of a load is necessary before the settle down?


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## Greg (Aug 1, 2007)

What type of load sharing device is installed? Woodward? It sounds as if the load sharing device needs adjustment. The load sharer controls the govenors to keep the load balanced. 

What is the total connected load? You may not have enough connected load to keep the gens from hunting.


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## micromind (Aug 11, 2007)

If there's too little droop in the regulators, they'll fight like that with little load. 

Are the gens the same make and model? If they're not, and they're different pitches, it's very difficult to make them work together.

Rob


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## brian john (Mar 11, 2007)

micromind said:


> If there's too little droop in the regulators, they'll fight like that with little load.
> 
> Are the gens the same make and model? If they're not, and they're different pitches, it's very difficult to make them work together.
> 
> Rob


Was on a job where a salesman sold a customer a 3rd unit to match two existing parallel units, with a different pitch after 1.5 years of trying his firm ate the cost of replacing the rear end of the prime mover


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## RyanCookston7788 (May 29, 2010)

jchom said:


> Question to the Power Plant and Industrial Electricians : What would be the primary and secondary causes for rapid occillating load swapping (particularly under lower power demands) between two electrical connected service gererators? To remedy the situation the load (speed controls) of one gen is lowered or raised to transfer load predominatly to one unit. This will greatly increase the system stability and reduce surging in load and voltage immensely.
> 
> The gens are rated at 600 KW 900 Amps 450 Volts.
> 
> JOE C


 In order to hook a load up to a generator! You have to Set them both on the same KW Amps and Volts and then make sure they are set at the same speed so you can put out the right amount of electricity!


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## RyanCookston7788 (May 29, 2010)

brian john said:


> Are these units paralleled or stand alone units on separate ATS's.
> 
> Have you monitored current, voltage and harmonics? If paralleled are the units matched same generator? same voltage regulators and governors.


In order to parallel you have to set both generators on the same speen and turn the voltage and amp to the same speed and make sure the green light is on in order for them to work correctly.


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## John (Jan 22, 2007)

jchom said:


> Question to the Power Plant and Industrial Electricians : What would be the primary and secondary causes for rapid occillating load swapping (particularly under lower power demands) between two electrical connected service gererators? To remedy the situation the load (speed controls) of one gen is lowered or raised to transfer load predominatly to one unit. This will greatly increase the system stability and reduce surging in load and voltage immensely.
> 
> The gens are rated at 600 KW 900 Amps 450 Volts.
> 
> JOE C


Sounds like the governors of one or both are not working correctly or they are going back and forth, Lead and lag. 
When they are connected together increasing the speed of one will cause that generator to lead more than the other and it will pick up more of the load. Just like dancing ....someone needs to lead. :whistling2:

I have seen 2 cycle (350 rpm) diesels in parallel with 4 cycle (1500 rpm) diesels and they run fine...it's just that one of them needs to be the lead generator.


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