Name Plate Issue
Name Plate Issue
(OP)
We have a recent generator rewind and upgrade. Runner was also refurbished. We asked the contractor/supplier to provide a name plate that would show exactly the power the generator would generate when coupled to the existing generator which is less than what the generator is actually designed for. But the contractor is insisting that they would only provide the name plate showing the rating specified in the contract and what the generator is capable of irrespective of the fact that this rating cannot be practically reached due to the limiting factor of undersized turbine.
Is our demand logical? Need the forums comments.
Thanks
Is our demand logical? Need the forums comments.
Thanks
Sarg






RE: Name Plate Issue
Gunnar Englund
www.gke.org
RE: Name Plate Issue
RE: Name Plate Issue
Sarg
RE: Name Plate Issue
Gunnar Englund
www.gke.org
RE: Name Plate Issue
I have dealt with rebuilders and refurbishers who, althought they certainly had the capability to do so, wouldn't guarantee their repair past what the original name plate said. They didn't want the liability.
rmw
RE: Name Plate Issue
In our case the contractor wants to provide a name plate with a higher rating 30MVA where as we are asking for 24 MVA. because this is what the generator can generate with the max available head and the present turbine. The thing is that we go with a higher rating we'll have to get into getting permits from the hydro authorities etc...
Just trying to get the forums advice on the eithical and logical solutions.
Appreciate your help.
Sarg
RE: Name Plate Issue
RE: Name Plate Issue
Gas turbines are usually designed as package units with a standard size generator to match the standard turbine package. It is not economical to have a seperate generator design for every application of a standard product, especially when all of the type testing and other Quality Control issues are considered. One design covers the complete range of output for the turbine package, so it will seem to be oversized in some cases.
The generator nameplate is specifed at some ambient temperature and cooling water or cooling air temperature, or H2 pressure and temperature. Most of the time, this does not match the ISO temperatures used in the turbine rating. When you adjust the turbine output and generator capability curves to the same amvient conditiosn, teh discrepancy is not as large.
Adding inlet air cooling equipment or using water injection can boost gas turbine output significantly. In some cases the generator is sized to allow future turbine output enhancements.
Remember that turbines are rated in MW, generators in MVA. Soem bids for Saudi Arabia required lower than normal power factor (0.80 lagging)capabililty with a margin. This led to oversize generator requirements.