Load unbalance in three phase generator

[Emadshaaban1987]

Hi folks,
1-What are the side effects of unbalanced loading of three phase generator?

2-What are the acceptable range of current unbalancing that will have no serious effect to the generator?

3-If the windings of generator has reconnected to be a single phase rather than three phase Does this affect the generator power capacity?

 

[waross]

1.Unbalanced loading will cause extra heating of the rotor.
2. It's a sliding scale. Damage depends on the amount of unbalance, the duration of the unbalance and the ambient temperature. Running windings at higher than rated temperature shortens the life expectancy. It may take a number of years for damage to become evident.
If you know that you have an unbalanced load, consider checking the insulation quality of the rotor every year or two. You may eventually decide to rewind the rotor to avoid an unplanned outage.
3. Capacity reduction for single phase conversion.

Single phase KVA capacity = 2/3 of the three phase KVA capacity.
Single phase KW capacity = 2/3 of the three phase KVA capacity.
Three phase PF 0.8, Single phase PF, 1.0
Single phase conversion connections.
1.Manufacturer recommended: Double Diamond.
2. Recommended for conversions on older machines: Zig-zag connection.
3. !0 lead machines: Bar Diamond or Collin's connection.

Bill
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Ohm's law
Not just a good idea;
It's the LAW!