Controller shows E05 and pump will not start, often after wiring changes

Safety first: Isolate power and verify with a tester before opening the motor terminal box.

• Check motor nameplate: Confirm the correct connection (star or delta) for the supply voltage. For example, 400 V three-phase may require star connection, while 230 V three-phase may require delta.
• Inspect terminal links: Open the Calpeda motor terminal box and verify that the brass links are installed according to the wiring diagram on the lid or nameplate. Correct any misplacement.
• Verify lead labeling: Ensure U1, V1, W1 (or equivalent) are connected to the correct supply phases. If leads are unlabeled, trace them carefully or consult a motor technician.
• Check for damaged leads: Look for burnt insulation, loose crimp lugs, or broken wires. Repair or replace damaged leads and tighten all terminal screws.
• Reset controller: After correcting wiring, reset the Calpeda controller and attempt a start. If E05 persists, the controller may be detecting incorrect rotation or an internal fault.