delay starting problem of EDG

[iamazeb]

We have 03 mtu EDGs of the same type having model # 12V 956 TB33.
Recently we are facing problem in our one EDG Engine , the problem is delayed starting of EDGs, it takes about 20 Sec. to reach its required RPM, while our requirement is, that the engine must start and reach at required RPM with-in 12 Sec. we have all the checks recommended in the vendor manual but the problem could not be resolved. e.g. checking of fuel system starting air system charge air system and all its related components and equipments.
It is to be noted that normal starting history of the engine, before this problem was about less than 10 Sec. same is for the rest of 02 engines.
if some one can help / suggest for resolving this issue.
thanks

 

[vpl]

Are you sure this is a mechanical problem rather than an electrical one? What changed between the times when you successfully passed the surveillence test at 10 seconds and when you didn't pass the surveillance test?

Patricia Lougheed

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[iamazeb]

in the 1st attempt it take about 18 Sec. to reach the required RPM while in the subsequent attempt with in 05 to 10 minutes, it reached the required RPM < 10Sec. the frequency of the surveillance test is one week for the problematic engine.
this shows that the problem is in mechanical not in electrical systems, however required electrical checked of starting system, AVR, excitation system were checked & found OK.

 

[vpl]

You have not given me anywhere close to enough information to be able to help you. My first guess (based purely on the limited information that you did two runs and one was 18 seconds and a second one was 10 seconds) is that either your fuel oil or your lubrication oil needs to be heated. But rather than asking you again, here's a link to the United States Nuclear Regulatory Commission web based Agencywide Documents Access and Management System Access Document system (commonly called ADAMS):

http://adams.nrc.gov/wba/

If you enter enter a document content of "diesel generator" and a document type of "NRC Information Notice" you will get approximately 400 Information Notices that the NRC has issued over the last 20 or so years of problems identified with diesel generators. In reading through those you might find something that speaks to your problem. I don't know.

Patricia Lougheed

******

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