Reasons for Unqualified Insulation Resistance of Electronic Ballast

Environmental and moisture reasons

1. Internal dampness and condensation caused by high humidity, poor ventilation or water leakage.

2. Water ingress from unsealed enclosure, cable glands and gaps.

3. Incomplete drying after maintenance, residual moisture on the circuit board.

2. Waterproof and process defects

1. Incomplete or uneven conformal coating with uncovered pins and solder joints.

2. Poor sealing: damaged gaskets, insufficient sealant, loose cable glands.

3. Air bubbles and voids in potting glue form moisture leakage paths.

3. Circuit board and component failure

1. PCB mildew, corrosion and creepage caused by humid and corrosive gas.

2. Aging or partial breakdown of capacitors, MOSFETs and rectifier bridges.

3. Heavy dust accumulation absorbs moisture and reduces insulation performance.

4. Operation and testing errors

1. Tested before conformal coating and sealant fully cured.

2. Wrong wiring or poor probe contact leads to inaccurate reading.

3. Water on surface or touching metal test points by hand affects results.

5. Structural and installation problems

1. Internal wiring too close to the metal enclosure with insufficient insulation distance.

2. Aging or damaged insulating gaskets and isolation parts.