OPERATION & MAINTENANCE

NOTICE

DAMAGE DUE TO IMPROPER MAINTENANCE

Proper maintenance is essential for ensuring system reliability and longevity. Follow the maintenance schedule as defined in the AES Cabinet Operation and Maintenance Manual (805-0094), which provides instructions on procedures and best practices.

Failure to follow these instructions may result in equipment damage.

NOTICE

RUST HAZARD

Always keep the cabinet doors closed when the product is operating or undergoing testing. If you leave the doors open, condensation may result, and prolonged exposure to condensation can rust metal components in the cabinet.

Failure to follow these instructions may result in equipment damage.

System Alarms (Cause & Troubleshooting)

NOTE

Level 1 and 2 Warnings, and Level 3 Faults

Level 1 and level 2 warnings will cause temporary system performance limitations, but the system recovers automatically once conditions normalize.
Level 3 faults require identifying and addressing the root cause of the alarm, and then performing a manual restart.

For more information, refer to Protections Specifications.

Alarm	Cause	Troubleshooting/Resolution
Abnormal Cell Voltage Low	Cell voltage too low due to imbalance or poor connections.	Adjust the charging system’s CV setpoint, track cell voltage, and discharge slowly. Replace the battery pack if necessary.
Abnormal Cell Voltage High	Cell voltage exceeds safe limits due to imbalance.	Adjust the charging system’s CV setpoint, track cell voltage, and initiate slow balancing. Replace the battery pack if needed.
Abnormally High Temperature	Temperature exceeds safe limits (>60°C). Possible TMS or battery pack issue.	Inspect TMS operation, check airflow and vents, ensure proper coolant circulation. Disconnect charger or load, and monitor system behavior. Replace TMS or battery pack if necessary.
Battery Pack Disabled	BCU detects a misconfigured BMU or BMU issue.	Check BCU and BMU configurations, verify pack communication cables, and reconfigure the system.
Battery Pack Offline	BMU missing or BMU-related issue detected.	Inspect MSD, verify BCU and BMU configurations, check pack communication cables, and reconfigure the system.
BCU Abnormal Voltage Rise	Cell voltage increasing too quickly due to imbalance or connection issues. (System Shutdown)	Restart the system, verify all pack connections, identify the affected battery pack, and track voltage. Replace the battery pack if necessary.
BCU Contactor Override	The contactor was manually overridden.	Return the system to auto-control mode and restart if necessary.
BCU Voltage Detection Fault	Inaccurate or disconnected voltage detection in HV Box. (Prevents System Start)	Inspect the MSD fuse, check BCU configuration, and verify all voltage detection connections. Replace the BCU if necessary.
Blown Fuse	HV Box fuse is open or blown due to overcurrent. (Prevents System Start)	Inspect fuse connections, check for continuity, and replace the fuse if needed.
BMU Hardware Fault	BMU hardware failure or internal fault. (System Shutdown)	Inspect the affected battery pack, check all BMU and pack connections (internal/external), and replace the BMU if necessary.
BMU Voltage Detection Fault	BMU voltage detection failure or disconnected voltage input. (System Shutdown)	Inspect the affected battery pack, verify internal BMU connections, test BMU operation, and replace the battery pack if needed.
BMU Communication Fault	BMU communication is inconsistent or unresponsive. (System Shutdown)	Check BMU and pack connections (internal/external), inspect for bent or corroded pins, and replace BMU or connectors if needed.
BMU Temperature Sensor Fault	BMU temperature detection failure. (System Shutdown)	Inspect internal BMU connections, verify BMU operation, and replace the affected battery pack if necessary.
Current Shunt Fault	Faulty or loose current shunt connections affecting monitoring. (System Shutdown)	Inspect shunt connections, check for discoloration, and replace the shunt if necessary.
EMS Communication Abnormal	Communication issue between BCU and EMS.	Restart LYNK, check connections, and restart the system.
EMS Communication Fault	Communication failure between BCU and EMS.	Restart LYNK, check connections, and restart the system.
EMS Contactor Override	The contactor was manually overridden by the user.	Return the system to auto-control mode and restart if necessary.
E-Stop Initiated	Emergency stop button manually triggered. (System Shutdown)	Verify the status of the E-Stop button and reset it if necessary.
LYNK Communication Abnormal	Communication issue between BCU and LYNK.	Restart LYNK, check connections, and restart the system.
Negative Contactor Fault	HV Box negative contactor not closing or not detected as closed. (Prevents System Start)	Check the 24V control system, verify I/O input and contactor wiring, and replace the contactor if faulty.
Pack High Delta Voltage	Excessive voltage difference between battery packs due to imbalance or poor connections.	Verify all pack connections, check MSD installation, and balance-charge packs individually.
Pack Quantity Misconfigured	Incorrect number of BMUs detected.	Verify MSD installation, check BCU and BMU configurations, ensure proper pack communication, and reconfigure settings.
Positive Contactor Fault	HV Box positive contactor not closing or not detected as closed. (Prevents System Start)	Inspect the 24V control system, verify I/O input and contactor wiring, and replace the contactor if needed.
Precharge Fault	Precharge process failed due to an open disconnect or excessive precharge load. (Prevents System Start)	Verify system wiring, check if PCS disconnect is open, and inspect precharge resistance. Retry the precharge sequence; replace precharge system components if necessary.