In testing a three-phase delta-connected winding for an open circuit using a ohmmeter, what must be done?

Correct Answer: Option C — if possible, open the delta-connections to avoid shunting the phase being tested

Testing a delta-connected winding with an ohmmeter requires opening the delta junctions to eliminate parallel shunting paths that mask single-phase open conditions. IEEE 45 standards dictate isolating individual phase groups for accurate resistance comparison and fault isolation.