From phase current to coil current in a delta system, how is the coil current obtained?

From phase current to coil current in a delta system, how is the coil current obtained?

• A. Divide phase current by sqrt(3)
• B. Add phase current to sqrt(3)
• C. Multiply phase current by sqrt(3)
• D. Subtract phase current from sqrt(3)

Answer: (C)

In a delta-connected system, the current in each line is the vector sum of the currents in the two windings connected to that line. Those winding currents are equal in magnitude and separated by 120 degrees. When you add two equal phasors that are 120 degrees apart, the resulting line current has a magnitude that is √3 times a single winding (coil) current. Therefore, to get the coil current from the phase current, you multiply by √3. This is why the coil current equals the phase current times √3 in this balanced delta relationship.

In a delta-connected system, the current in each line is the vector sum of the currents in the two windings connected to that line. Those winding currents are equal in magnitude and separated by 120 degrees. When you add two equal phasors that are 120 degrees apart, the resulting line current has a magnitude that is √3 times a single winding (coil) current. Therefore, to get the coil current from the phase current, you multiply by √3. This is why the coil current equals the phase current times √3 in this balanced delta relationship.