Applicable Systems
BYD Battery Management System
Symptoms
The BYD BMS reports alarm BY010, indicating a ground fault detected. A current leakage path from the battery pack to the chassis ground has been detected by the ground fault detector, triggering a safety shutdown.
Possible Causes
- Cable insulation failure between the battery pack and the vehicle or system chassis
- Moisture or conductive debris inside the enclosure creating a leakage path from the cells to the chassis
- AC component or inverter leak current coupling through the DC bus to the chassis, triggering the detector
Troubleshooting Steps
- Step 1: Isolate the battery pack and measure insulation resistance to chassis with a megohmmeter at 500V DC
Insulation resistance is above the safety threshold of 100 ohm per volt of pack voltage - Step 2: Inspect the enclosure interior for moisture, condensation, or conductive debris
Enclosure interior is clean, dry, and free of any conductive debris or moisture - Step 3: Check the inverter DC bus insulation and the Y-capacitor condition for leak current coupling
Inverter DC bus insulation is above threshold and the Y-capacitors show no degradation
How to Reset
To reset: 1) Locate and repair the insulation failure. 2) Dry and clean the enclosure. 3) Replace degraded Y-capacitors. 4) Restart BMS and verify no ground fault alarm recurs during operation.
Source: BYD Battery Management System Manual, BYD Company Limited
Category: Battery