The significantly higher resistance you are measuring across two pairs of motor leads in your BLDC motor suggests there may be an issue with the winding insulation or connections within the motor. Here are a few potential causes to consider:
Winding Damage: The higher resistance could be due to damaged windings. This damage can result from overheating, mechanical stress, or manufacturing defects, causing partial breaks or poor conductivity in the windings.
Insulation Breakdown: If the insulation between the windings has deteriorated or failed, it can lead to increased resistance. This could be due to aging, exposure to moisture, or harsh operating conditions.
Poor Connections: Check the connections between the motor leads and the windings. Loose or corroded connections can create additional resistance, leading to the readings you're seeing.
Internal Short: There might be an internal short circuit within the windings that isn't a complete break but still disrupts the normal resistance.
To pinpoint the issue, you can:
Perform a visual inspection of the motor windings and connections if possible.
Use an insulation resistance tester (megger) to check the integrity of the winding insulation.
Compare the resistance readings with those from a new or known-good motor of the same type, as you have already done.
If the problem persists and you can't identify a clear cause, it may be best to consult with the motor manufacturer or a professional repair service for a more in-depth diagnosis.
