Burning Alternator

By "burns" do you mean it overheats? Or does it actually burst into flame?

If it is overheating, have you taken actual temperature measurements--electric equipment can feel very hot to the touch without actually being over its rated temperature...

yes it is overheating. i never take the temperature but you cannot touch it. the exciter stator is shorted when i megger it and other alternator exciter rotor is splitted and disconnected from the rectifiers.

You need to measure the temperature.

When you say the stator is shorted when measuring with a megger, do you mean it is shorted to ground? A megger is not a suitable instrument to measure the resistance of the stator coils--they will have a very low resistance in the range of ohms, possibly less than an ohm.

A megger measures millions of ohms.

Maybe the "low load" it is left to cope with is still too big for it?

I have seen, also - on a transformer - how disbalance of voltages of just 3 % across the 3 phases led to disbalance of currents across them of 40 %! (load was induction motors)

What is a Quadrature KIT??

Your problem started after fitting this kit?

Strange to me.

Before alternator burn, is there any fault code on deepsea or controller ? mention what are protection you have installed in panel ?

there is no indication before it was burn. it will only indicate undervoltage after. this is the only protection that i put which comes from the controller. what do you suggest other than this? that will protect the rotor from overheating.

I'm still trying to understand if there is really a problem.

Was the winding insulation damaged / destroyed by heat?

I'm still trying to understand if there is really a problem.

Was the winding insulation damaged / destroyed by heat?

what im trying to sort out is that the reason why the rotor is overheating and how can i eliminate it. because aside from the main rotor, the exciter stator is shorted.

i dont think its the reverse power that causes this problem because the generator is running stand alone. the generators were stock for almost a year before set-up.

another solution that im thinking is the static mode do you think it will be effective?

what do you mean by "single mode"? Does it mean single phase loading? One of the possible reason of generator failure could be unbalanced load. This causes rotor heating and may result in burning of rotor winding. You may like to check the unbalance load carrying capacity of the generator (see manufacturers documents).

Re: what do you mean by "single mode"? Does it mean single phase loading?

I'm not the OP, but reading the OP, my understanding is that he has 3 500kva generators, and single mode, for him is running only one of those generators due to low load.