whenever we try to put any load be it 1 megawatt or base load on a GE frame 5 with a markV it gets up to max rpm and starts synchronizing and then it times out and we have to raise and lower it manually to get it to finally sync. any suggestions

thanks

 

I don't really understand the question do you try to synchronize the TG with already some load on it?

If it times out (normally after three tries) it probably means that your synchr windows is too narrow for the synchro relay to pick up the correct synchro what are your settings DV, DF, and slip frequency windows both on Mark5 and synchro relay?

one way to see it is that the synchronscope should SLOWLY rotate CLOCKWISE and try to close the breaker just a little bit Before 12 o'clock. faster it goes and less chance you have to synchronize

 

When did this problem start?

When you say "... it times out ..." do you mean that the 'Failure to Synhcronize' alarm is annunciated? Does the Automatic Synhcronization actually abort when the alarm is annunciated? Because if it does, then the sequencing is not standard; that alarm just means it's taking longer to automatically synchronize than anticipated (usually 30 seconds after Auto Synch is initiated), but it doesn't normally abort the Auto Synch sequence. But, stranger things have been done to sequencing; it won't harm anything if the Auto Synch sequence is aborted, it's just not typical GE sequencing to abort the Auto Synch attempt if it takes longer than anticipated.

What is the frequency of the grid you are synchronizing to? Is it stable? Is it higher or lower than nominal? Much higher or much lower than nominal?

Has the grid frequency been steadily getting more off nominal over time? Could this be the reason that it's taking longer to synchronize, automatically or manually?

 

To get the auto synch. to run, your system has to be within certain parameters of voltage and frequency. have you checked the synchro. page in the demand display when you are trying to synch. Is the Auto Synch. active, I think L83AS. Is 25P good "1", this is the synch. permissive. What is your System voltage and frequency when you are trying to synch. to it

 

Bob Johnston makes an excellent point: Have you looked at the six green "dots" on the Synchronizing Display to determine what permissive or permissives is/are not met? Any "dot" that is red (the "dot" will change from red to green when the permissive is met).

But, again, when did this problem begin, and what is the frequency of the grid you are trying to synchronize to?

If you are trying to synchronize a unit with some load to another source (sometimes called "Second Breaker Synch") has this been successful in the past or is this something you are just trying now?