Final Inspection for Toroidal Cores Dimensional Check: Verify outer diameter (OD), inner diameter (ID), height, and concentricity meet drawing specifications.
Visual Inspection: Ensure the core is free from physical damage, rust, contamination, and any irregularities in the winding pattern.
Interlayer Insulation Test: Check for electrical shorts between winding layers using a low-voltage resistance measurement at multiple points on the outer surface.
Ground Insulation Test: Measure insulation resistance (> 500 MΩ typical) between the core laminations and any mounting hardware or baseplate.
Excitation Test (Performance Verification): Wind a temporary test coil and apply an AC voltage to measure no-load loss and exciting current. Results must be within specified limits (e.g., ≤ +15% of design value). This is the ultimate quality proof.
