Last updated B.Hornby

Example 1

This example is starting a single phase motor on a single phase transfomer.

Results

In this example the maximum voltage dip has been exceeded at both the point of common coupling and the LV terminals of the transformer. Even if the customer had a dedicated line from the transformer the dip would exceed voltage limits for any other customers connected to the transformer.

If the transformer was dedicated for the sole use of the customer this solution would be acceptable,

If the transformer was uprated to single phase 25kVA, the voltage dip at the point of common coupling would still exceed 5% (5.54%). The transformer volts would be OK (2.75%) to supply other customers from the LV terminals.