ATEF

You have posted this 3 times in the past month, and have ignored the responses and/or not responded to most requests for more information. It is time for you to search CR4 for previous answers to similar questions, to learn how these systems work, or pay someone to do your work for you.

As you have been told, this is a repetitive question!

You did not respond before on request for more info or to do certain test/data gathering (by the way 'together' not 'to gather' in your text!!).

In any case, for what it is worth: kW and currents are not enough info to help you. You need the full picture for each unit: kVA, kVAR, kW and the currents, and also, the power factor viewed by each unit.

G3 current could be higher than the others while its kW is the same because the p.f. is different (which means the kVA is different). When you go back to the main supply, releaving all the gensets from their loads and still in paralllel, the whole picture will change since the reactive power required by the load has suddenly been removed. Therefore, depending on the position of the excitation status just before the changeover, there will be some stabilising backflow or forward flow of current between the 3 units. Thus a probability of reverse flow into G3 in this case (?).

Take it from here...

Two things are obvious here.

1. You have no understanding of the problem at hand, or the solution.

2. This forum is incapable of infusing you with un-possessed knowledge you desire.

Hire a competent electrical engineer or technician to fix the problem.