synchronous two generators

[orionga]

I am a technician in the generator industry.
Nice to join you in the forum. I have a problem that needs to be solved is to synchronize two cummins generators. one for 1800rpm and one for 1500rpm.
I want to draw two machines at a speed of 1500.
I need help from the community to get 1800 rpm to 1500 rpm.
Thanks for reading and writing

 

[crshears]

Dear Orionga:

You have a problem...

A directly driven 1800 rpm AC generator having two sets of poles per phase will have an output frequency of 60 Hz.

A directly driven 1500 rpm AC generator having two sets of poles per phase will have an output frequency of 50 Hz.

Perhaps you can see why these cannot be synchronized...not to mention you have not stated which nominal frequency of power you desire to generate.

One answer: for 50 Hz, slow down the 1800 rpm machine to 1500 rpm [ I would not recommend speeding up the 1500 rpm machine to 1800 for 60 Hz ].

Another answer: For 50 Hz, on the 1800 RPM engine, insert a 6:5 ratio speed reduction gearbox to lower the speed of its generator to 1500 rpm.

Still another answer: For 60 Hz, on the 1500 RPM engine, insert a 5:6 ratio speed increasing gearbox to raise the speed of its generator to 1800 rpm, provided the generator can handle the increased speed-cubed centrifugal and other stresses.

Re-reading my response, I realize that another perhaps is that perhaps you have not given us enough background for us to fully grasp what it is you are attempting to do and what your problem actually is.

As another participant here has often stated: "Providing more information yields better answers."

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[waross]

Adjust the governor on the fast machine down. Normal no-load setting for a 50 Hz machine is 1545 RPM or 51.5 Hz. (+3%)
Change the UFRO jumper on the AVR from the 60 Hz position to the 50 Hz position.
The Ampere rating of the windings will be the same.
The engines on almost all diesel gen-sets manufactured by the major manufactures are the same whether run at 1500 RPM or 1800 RPM.
When I was doing a lot of generator work I spent hours going over manufacturers spec sheets and comparing actual engine and generator end model numbers for a lot of sets.
The range that I was studying was from 15 KVA up to about 500 KVA.
The same engine and generator end combination could be found with four different ratings.
50 Hz Standby
50 Hz Prime Power
60 Hz Standby
60 Hz Prime Power
The engines are not made by the gen-set builders.
The engines are bought from Perkins, Cat, Cummins or other engine makes.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[catserveng]

Most Cummins Genset engines had dual 50/60Hz rating, however newer engines, mainly Tier 4, are NOT dual rated because of strict emissions regulations. So if you want to change ratings on those it usually requires a change in turbos and fuel system components.

You really need to provide more info about the units you have before the question can be properly answered.

Who packaged the sets? Are they Cummins units or packaged by someone else.

How old are the units? Also what kind of auxiliary equipment do they have? Units with electric radiator fans and ventialtion systems are less likely to be easily compatible.

Some packagers, like Aggreko, do a nice job of making sure most of their units are dual purpose 50/60Hz, but there is a lot of extra equipment in the package to make that happen.

Might also help to know where in the world you're at, likely not North America since you seem to want to go 1500 RPM.

Likely your best answers will come directly from the equipment supplier.

Hope that helps, MikeL.