Energy Storage System Caterpillar

Module Level Faults

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Module Level Faults

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Table 1
Fault Name	Description	Troubleshooting Steps
Cathode Fan - Open Circuit Cathode Fan - Short Circuit	The fault message indicates that one or more cathode fans have failed. The module cannot distinguish between the fans for cells 1 through 9 or the fans for cells 10 through 18. Therefore, the fans on both sides of the module must be confirmed for proper operation.	1. Check fans for obstructions that may prevent the fan from spinning. 2. Check the cathode fan harness connections. Troubleshooting includes checking any extension harnesses used for expansion enclosures. 3. Perform a pull test on the connectors and terminals to verify that there are no loose crimped connectors or terminals connections. 4. Check connectors and terminals for corrosion. 5. Inspect the cathode fan harness for loose, broken, or shorted wires. 6. Replace any harness that has terminals or connectors that are broken, have corrosion, or wires that are shorted. 7. If all connections are good, and there are no signs of corrosion, replace one cathode fan. Reboot the module and observe if a fault is still present. If the fault is still present, replace the first fan again. This is done to avoid unnecessarily replacing a working fan. If the fault is still present, contact product support. 8. Verify that the fault is cleared by either placing the system into discharge or rebooting the module.

Cathode Fan - Power Supply Failure	The message indicates that the power supply for the cathode fan has failed on the module board.	1. Replace the module board.

CO2 Scrubber - CO2 Scrubber Life Low	The message indicates that the CO2 scrubber media is reaching the end of life.	1. Replace the CO2 scrubber media cartridge. 2. Reset the CO2 life meter back to 100% by using either FST or Over The Air Command (OTAC). Use the "Set Scrubber Volume" command to set the value to zero. ⁽¹⁾

CO2 Scrubber - CO2 Scrubber Recommended	The message indicates that the system is seeing a high number of discharge hours. The high number of discharge hours may cause the cell electrolyte to have a high amount of carbonate.	1. Install a CO2 scrubber in all the modules in the system. 2. Verify that the CO2 scrubber life is at 100%. If the scrubber life is not set at 100%, reset the life meter by using the "Set Scrubber Volume" command. The value must be set to zero.

Module Charge - Current High PBMS Charge - Input Current High	The charge current on the module is high.	1. Replace the module board.

Module Charge - Current Low	The charge current on the module is low.	1. Replace the module board.

Module Charge - Impedance Critical High Module Charge - Impedance High Module Discharge - Impedance Critical High Module Discharge - Impedance High PBMS Charge - Impedance Critical High PBMS Charge - Impedance High	The messages indicate that there is high impedance at one or more locations in the module. The error is typically due to a loose connection at the cell terminals, but could indicate an undetected field-effect transistor (FET) failure on a cell.	1. Ensure that all interconnections between the cells are tightened. In the power module, check all connections to fuses, contactor, and the power cell. 2. Ensure that all module power connections at the module board are tightened. 3. Check for signs of contamination on the cell interconnections and the cells. 4. Use FST or OTAC to execute the Open and Short Circuit Test command. The command is used to determine if there are any failed field-effect transistors that are causing an issue. 5. If the fault persists, follow the steps below to identify what cell is causing the problem. a. Remove cell 1 from the faulty module and install cell 1 into a working module. Test the working module in charge and discharge to see if the fault appears. If the fault appears, remove the cell from the working module. Return cell 1 to the original module. Return all cells to original positions. b. Test the faulty module in charge and discharge with a new cell. If the fault appears, repeat step (a) above for cells 2 through 18. c. Ensure that all the original cells are put in the original locations when finished.

Module Charge - Output Current Error High PBMS Charge - Output Current Error High	The output current of the module is not within tolerance.	1. If a PBMS is used, replace the BMU. If problem persists, replace the module board. 2. If an EBMS is used, replace the module board.

Module Charge - Power Limited PBMS Charge - Power Limited	The module is in a power limited state and reduced the module charge current. The fault can occur when AC input to the rectifier or rectifier capacity is limited.	1. Verify the rectifier settings per the installation manual. The rectifier must have the parameters set to provide ample charge current for the system and site load while in the "grid-on" state. 2. Verify that the rectifier capacity will allow ample charge current for the system and site load while in a grid-on state. 3. Verify that the AC input to the rectifier is not low or experiencing a brownout.

Module Charger - Charger Fan Current High	The fan current for the module charger fan is high.	1. Replace the module board.

Module Charger - Charger Input Current High	The input current to the module charger is high.	1. Replace the module board.

Module Charger - Charger Output Voltage High PBMS Charger - Output Voltage High	The output voltage to the module charger is high.	1. Check all interconnections between the cells for proper torque. 2. Check all module power connections to the module board to ensure that the connections are correctly torqued. 3. Check for signs of contamination on the cell interconnects or the cells.

Module Charger - Charger Output Voltage High PBMS Charger - Output Voltage High⁽²⁾	The output voltage to the module charger is high.	1. Use FST or OTAC to execute the open and short circuit test command. Use the command to determine if there are any failed field effect transistors that are causing a problem. 2. If the fault persists, use the following steps "a" and "b" to help identify the cell that is a problem: a. Remove cell 1 from the faulty module and install in working module. Test working module in charge and discharge to see if fault appears. If fault appears, replace the cell and put the cell into original module. Return all cells to the original positions. b. Test the faulty module in charge and discharge with a new cell. If the fault appears, repeat steps in "a" above for cells 2 through 18. 3. Ensure that all original cells are placed back in the original locations. 4. Replace the module board.

Module Charger - Charger Output Voltage Low PBMS Charger - Output Voltage Low	The output voltage to the module charger is low.	1. Check all connections. 2. If problem persists, replace the module board.

Module Charger - Charger Temperature High PBMS Charger - Temperature High	The charger temperature is high.	1. Place the module in charge and check charger fan. Check for signs of open/short circuit or obstruction on the fan preventing the fan from spinning. 2. Replace charger fan if found failed. 3. Check cabinet fans, repair as needed. Put system and charge and see if fault persists. If fault persists, replace the module board.

Module Communication - Local Interconnect Network (LIN) Communication Failure	There is a communication failure on the LIN bus in the module. The problem can be due to a single cell or multiple cells. Also, the fault can be due to a result of a LIN cable failure.	1. If all cells are experiencing a LIN communication failure, the LIN cable or module board may be causing the problem. a. Check the LIN connections at the EBMS. b. If fault persists, replace the module board first and see if the fault is resolved. If the fault is not resolved, replace the LIN communication cable. Install the original module board since there is no issue with the board. 2. If one or more cells, but not all, are experiencing a LIN communication failure, one or more cells may be causing the problem. Follow the steps below to aid with troubleshooting: a. Use FST or OTAC to execute the "Address Cells" command to verify that all cells have the correct address. b. Check the connections to the cells. c. If a cell fails to address, replace the cell and repeat step "a" above. d. Replace all cells that fail to address.

Module Communication - No CAN Data From Comm Control PBMS Communication - Primary CAN CC Fault PBMS Communication - Primary CAN General Fault	Indicates that there is no CAN data being received from the communication control board.	1. Check the communication control to see if the HB and HKPS LED is on. If there is an issue with the communication control, the board will not send data to the module boards. 2. Check all CAN communication harness connections.

Module Communication - No CAN Data To Comm Control	Indicates that there is no CAN data being received from the communication control board.	1. Check the fuse on the module board. a. If the fuse is open, inspect the module for signs of short circuit and address as necessary. Replace the fuse after ensuring no short circuit exists on the module. If no fuse is available, replace the module board. b. If the fuse is open, use the following steps to aid with troubleshooting if needed. Do not replace the module board at this time. 2. Verify that the addresses on the dip switches of the module board match the physical locations and that no duplicate addresses are present. 3. Turn off the module board for 10 seconds. Turn on the module board and see if the fault persists. If the fault persists check for a LIN communication short. 4. Check for a LIN communication short by disconnecting the two ribbon connectors from the module board. a. If the appropriate LED lights do not come on, there is an issue with the module board. Replace the module board. b. If the LED lights do illuminate, there is a LIN communication short on the module. Follow the steps below to determine if the problem is a ribbon cable or a cell. 5. Confirm if there is a ribbon cable failure by connecting the ribbon connectors to the module board and disconnecting the ribbon connectors from all cells. a. If the HB and HKPS LED lights do not come on, there is a ribbon cable failure. Replace the ribbon cable. b. If the HB and HKPS LED lights do illuminate, the issue is with one more of the cells. 6. To determine which cell or cells are causing an issue, connect the ribbon connector for each cell one by one. a. If the LED lights turn off when a cell is connected, replace the cell. Repeat the process until all cells are checked. 7. If the problem cannot be resolved with the steps listed above, replace the module board.

Module Discharge - Current High PBMS Discharge - Current High	The discharge current on the module is high.	1. Replace the module board.

Module Memory - EEProm Error PBMS Memory - General EEProm Fault	There is an error reading and/or writing to the EEProm on the module board.	1. Replace the module board.

BMU - Abnormality	There is an abnormality on the BMU.	1. Replace the BMU.

BMU - Cell Balance Fault	There is a cell balance fault on the BMU.	1. Replace the BMU. 2. If problem persists, replace the power cell.

BMU - Cell Management Unit (CMU) Fault	A CMU fault is being reported by the BMU.	1. Replace the BMU. 2. If problem persists, replace the power cell.

BMU - Overcharge Fault	There is an overcharge fault on the BMU.	1. Replace the BMU. 2. If problem persists, replace the module board. 3. If problem persists, replace the power cell.

BMU - Over discharge Fault	There is an over discharge fault on the BMU.	1. Replace the BMU. 2. If problem persists, replace the module board. 3. If problem persists, replace the power cell.

BMU - Temperature Critical High BMU - Temperature High	There is a high temperature fault on the BMU.	1. Replace the BMU. 2. If problem persists, replace the power cell.

PBMS Charge - Fan Fault	There is a fan fault on the module.	1. Replace the module board fan. 2. If problem persists, replace the module board.

PBMS Communication - Secondary CAN General Fault		1. Inspect harness to BMU from PBMS. 2. Replace BMU. 3. If the problem persists, replace the module board.

PBMS Contactor - General Fault	The module is reporting a general fault.	1. Check connections between PBMS and BMU and between BMU and Li-Ion battery. 2. If the problem persists, replace the BMU. 3. If the problem persists, replace the PBMS. 4. If the problem persists, replace the Li-Ion battery.

PBMS Discharge - Booster Fault	There is a booster failure on the module board.	1. Replace the module board.

PBMS Discharge - Voltage Low	The discharge voltage on the module board is low.	1. Replace PBMS. 2. If the problem persists, replace the Li-Ion battery.

PBMS Measurement - Module Voltage Error	There is a voltage measurement error on the module board.	1. Replace BMU. 2. If problem persists, replace the module board.

PBMS Measurement - SOC Error	There is an SOC error on the module board.	1. No immediate action necessary. However, if the problem is recurring frequently, replace the BMU. 2. If the problem persists, replace the power cell.

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⁽¹⁾	The value must be set for each module. Typically, the media will expire around the same time for all modules.
⁽²⁾	The steps related to this fault message are for the "Energy Module Fault ONLY".