Protections Specifications

AES Cabinet Protection Specifications

Specification	Description
Cell Overvoltage
Level 1^(a)	≥3.55 V for 5 s: Charging is derated. Discharging is allowed. Consequence: Charging is reduced to avoid overvoltage.
Level 2^(a)	≥3.60 V for 5 s: Charging is stopped. Discharging is allowed. Consequence: Charging is halted to protect against overvoltage. Discharging is still available.
Level 3^(b)	≥3.65 V for 3 s: System shuts down. Charging and discharging are halted. A manual restart is required.
Cell Undervoltage
Level 1^(a)	≤2.90 V for 5 s: Discharging is derated. Charging is allowed. Consequence: Discharging is reduced to avoid undervoltage.
Level 2^(a)	≤2.80 V for 5 s: Discharging is stopped. Charging is allowed. Consequence: Discharging is halted to protect from battery undervoltage. Charging is allowed.
Level 3^(b)	≤2.60V for 3 s: System shuts down. Charging and discharging are halted. A manual restart is required.
Cell Imbalance
Level 1^a)	≥350 mV for 5 s: Charging and discharging are derated. Consequence: Charging and discharging current are reduced to balance cell voltage differences.
Level 2^(a)	≥400 mV for 5 s: Charging and discharging are stopped. Consequence: Charging and discharging are halted to avoid imbalance between cells.
Level 3^(b)	≥500 mV for 3 s: System shuts down. Charging and discharging are halted. A manual restart is required.
Battery Pack Overvoltage
Level 1^(a)	≥184.6 V for 5 s: Charging is derated. Discharging is allowed. Consequence: Charging is reduced to avoid overvoltage.
Level 2^(a)	≥187.2 V for 5 s: Charging is stopped. Discharging is allowed. Consequence: Charging is halted to protect against overvoltage.
Level 3^(b)	≥189.8 V for 3 s: System shuts down. A manual restart is required. Consequence: Total system shutdown to protect against damage from overvoltage-related failure.
Battery Pack Undervoltage
Level 1^(a)	≤150.8 V for 5 s: Discharging is derated. Charging is allowed. Consequence: Discharging is reduced to avoid undervoltage.
Level 2^(a)	≤145.6 V for 5 s: Discharging is stopped. Charging is allowed. Consequence: Discharging is halted to protect against undervoltage.
Level 3^(b)	≤135.2 V for 3 s: System shuts down. A manual restart is required. Consequence: Total system shutdown to protect against damage from undervoltage-related failure.
Battery Cabinet Discharge Current
Level 1^(a)	≥150 A for 5 s: Discharging current is reduced by the BMS. Consequence: Discharging is reduced to avoid overcurrent.
Level 2^(a)	≥155 A for 5 s: Discharging is stopped. Charging is allowed. Consequence: Discharging is halted to protect against overcurrent damage.
Level 3^(b)	≥160 A for 3 s: System shuts down. A manual restart is required. Consequence: Total system shutdown to protect against damage from discharge overcurrent-related failure.
Battery Cabinet Charge Current
Level 1^(a)	≥150 A for 5 s: Charging current is derated by the BMS. Consequence: Charging is reduced to avoid overcurrent.
Level 2^(a)	≥155 A for 5 s: Charging is stopped. Discharging is allowed. Consequence: Charging is halted to protect against damage from overcurrent.
Level 3^(b)	≥160 A for 3 s: System shuts down. A manual restart is required. Consequence: Total system shutdown to protect against damage from charge overcurrent-related failure.
Low Insulation Resistance
Level 1^(a)	≤1000 kΩ for 2 s: Charging and discharging are derated. Consequence: Charging and discharging are derated to avoid issues from reduced insulation resistance.
Level 2^(a)	≤500 kΩ for 2 s: Charging and discharging is stopped. Consequence: Charging and discharging are halted to protect against damage from poor insulation.
Level 3^(b)	≤100 kΩ for 2 s: System shuts down. A manual restart is required. Consequence: Total system shutdown to protect against damage from insulation-related failure.
High Temperature
Level 1^(a)	≥40°C 104°F @ Charge for 5 s / ≥45°C (113°F) @ Discharge for 5 s: Charging and discharging current are reduced. Consequence: Current is derated to avoid high temperatures.
Level 2^(a)	≥45°C (113°F) @ Charge for 5 s / ≥50°C (122°F) @ Discharge for 5 s: Charging and discharging are stopped. Consequence: Charging and discharging are halted to protect against high-temperature damage.
Level 3^(b)	≥50°C (122°F) @ Charge for 3 s / ≥55°C (131°F) @ Discharge for 3 s: System shuts down. A manual restart is required. Consequence: Total system shutdown to protect against damage from high-temperature-related failure.
Low Temperature
Level 1^(a)	≤10°C (50°F) @ Charge for 5 s / ≤5°C (41°F) @ Discharge for 5 s: Charging and discharging current are reduced. Consequence: Charging and discharging are derated to avoid damage in low temperatures.
Level 2^(a)	≤5°C (41°F) @ Charge for 5 s / ≤0°C (32°F) @ Discharge for 5 s: Charging and discharging is stopped. Consequence: Charging and discharging are halted to protect against low-temperature damage.
Level 3^(b)	≤0°C (32°F) @ Charge for 3 s / ≤-10°C (14°F) @ Discharge for 3 s: System shuts down. A manual restart is required. Consequence: Total system shutdown to protect against damage from low-temperature-related failure.
High Terminal Temperature
Level 1	≥70°C for 5 s: Warning only.
Level 2	≥75°C for 5 s: Warning only.
Low State of Charge
Level 1	≤10% for 5 s: Warning only.
Level 2	≤0% for 5 s: Warning only.
(a) Level 1 and Level 2 Warnings: These will cause temporary system performance limitations, but the system should self-recover automatically once conditions normalize. (b) Level 3 Alarm: This will trigger a system shutdown and maintenance alarm. To restore operation, identify and address the root cause of the alarm, then perform a manual restart.