Examining the Wiring
3. Tracing the Electrical Paths
A close visual inspection of the motor's terminal box can often reveal the connection type. Look for the arrangement of the terminals and any connecting links or straps. In a star (wye) connection, you'll typically see three terminals connected together (either directly or with links), forming a "star point" or neutral point. The other ends of the windings are then connected to the supply voltage.
In a delta connection, the windings are connected end-to-end in a closed loop, forming a triangle or "delta." You'll usually see three sets of terminals, with each set connecting to two different windings. There's no central "star point" in a delta configuration.
Pay attention to any markings on the terminals (U, V, W, or T1, T2, T3, etc.) and try to trace the connections to understand how the windings are interconnected. Sometimes, a wiring diagram is printed inside the terminal box cover, which can be a lifesaver.
Imagine the wiring as a road map. Following the roads (wires) will lead you to the destination (the connection type). If you see a central hub where three roads converge, thats likely a star point. If you see a closed loop with roads connecting end-to-end, thats likely a delta.
