1. A balanced three-phase system consists of positive consequence components only.
2. In a balanced three-phase system the negative and zero sequence components being zero.
3. The presence of negative or zero sequence component introduces asymmetry in the three phase system.
4. The presence of negative and zero sequence currents are the indication of abnormality in the system.
5. The vector sum of the positive and negative sequence currents of an unbalanced three phase system is zero.
6. The vector sum of all sequence currents in three phase system unbalanced is equal to IRo + IYo + IBo.
7. Three phase four wire system zero sequence current is equal to one-third of the sum of current in the neutral wire.
8. The current of a single phase load drawn from a three phase system comprises equal positive, negative and zero sequence components.
9. In the unbalanced three phase system, the magnitude of negative sequence component cannot exceed that of the positive sequence component. The phase sequence should be reversed if the negative sequence components were the greater.
10. A delta-connected load has no neutral path and the line currents
to delta-connected load can contain no zero-sequence components.
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