🔍 Key Concepts

• How clamp-on probes on a harmonic analyzer work and what electrical quantity they measure (current vs voltage). • How to distinguish the primary (delta) side from the secondary (wye) side of a transformer in a terminal box drawing. • The relationship between where the probes are placed (line cables vs transformer terminals) and what part of the transformer is being tested.

💭 Think About

• Look closely at figure D: Are the analyzer’s sensors wrapped around conductors or directly connected across terminals? What does that tell you about whether current or voltage is being measured? • In the terminal box, which side is identified with the wye symbol, and where do the numbered terminals lead? Do the connected conductors appear to go toward the line/load side or directly into the transformer? • If the transformer is delta-to-wye, which side would normally be shown with the wye symbol in a terminal box, and how does that help you decide whether the test is on the primary or secondary side?

✅ Before You Answer

• Verify whether the probes shown are current clamps or simple voltage test leads. • Confirm which group of terminals and conductors in the illustration corresponds to the wye (secondary) side of the transformer. • Double‑check that the answer choice you pick matches both the quantity being measured (current vs voltage) and the transformer side (primary vs secondary) indicated by the drawing.