Diesel Generator Issue

You're assuming a hell of a lot, like the OP knows what he's doing.

OP Ask yourself, who do you trust, RAM who I know has good knowledge of generator sets but doesn't know your particular set up or the generator manufacturer?

Have you altered the sets without prior advice? More fool you if you have is all I can say.

RAM full respect to you. You always give good advice.

Sometimes it's an uphill struggle!

At least with moving a load uphill there's usually only gravity and friction to fight. Here there's a myriad of factors to try to account for. Nearly all going the wrong way!

Good answer by RAM. If you follow guide lines, you should be out of problem.

Few things to add. Check controller fitted on Genset. Does it have capability to have good communication with PLC.

Who designed and supervised the retrofit? They should be able to sort this out... per RAM's suggestions for starters...

If you are the one wearing the can and need some help then calm down and explain your setup and observed problems more clearly. I can't model what you described in my head other than you have a load sharing issue.

Start with a sketch perhaps?

If you have swapped controllers, verified wiring, and CT/PT polarity is correct, the only remaining root cause would logically be a master programming fault or PLC I/O card fault.

If possible I would exchange the #2 machine program position in the system with the #3 machine program position and see if the issue follows the program machine postion assignment.

If the issue follows the assignment:

I would exchange the associated PLC I/O card and see if there is a change then react accordingly by replacing the card.

If exchanging the I/O card postion does not affect the issue location, I would go online with the program and look for a math register error such as an "overflow" or "wrapping" of real time DATA values in the program that is specific to the system excitation control. This error is common due to programmers failing to set the upper and lower DATA value limits.