Phase Imbalance Problem - Welding Transformer

With one phase not connected the equipment behaves as though it is a single phase appliance at 415V. It's no problem in principle, provided the supply can handle it. And if it can't then expect a circuit protective device to operate, maintaining safety of the supply cabling.

It's Ok,

But during welding input current will flow only in two phase & one will be free, in this condition generator get loaded on two phase only & some times Generator trips,so what is solution to balance the load of three phases.

I don't know if I am not wrong we can connect three welding machines in this way that all phases should be loaded equaly.

i.e one will be between R & Y

Second will be Between Y & B

Third will be between R & B

What you say ??? is correct or not.

My mainn query is to balance the load of My Generator.

You are correct in principle but it is not likely that all the welding machine will operate simultaneously and at similar power. But if you have many, do distribute them on the three phases.

If your generator is large enough to handle 2 phase loading of your welder there should be no problem.

Fitting 3 welders to balance the phases wont work it will be worse because the total load will kill your generator if it cant handle a two phase load. in any case your welders will never be truly balanced as their individual loads are variable and intermittent.

1. Why are you posting in this forum? assuming you are not student (are you?) you should have been in EE forum for more exposure. Of course if it is a part of education then this is OK.

2. The generators are typically able to take about 10% or so current in negative sequence (caused due to phase imbalance)

If your generator is large enough then it can probably accommodate the unbalance caused since the 400A at outlet will translate to only somewhere about 20A or so at inlet.

Also your generator is likely to be protected against the phase unbalance relays. Check them. However if you feel the unbalanced load/total load is high, use 3 phase welding generator/rectifier. Infact for our facility all are 3 phase only whether solid state or the old generator type.