Low-voltage of Capacitor Module (ECM)
Fanuc · Macro B CNC Programming
What does 8 mean?
A low-voltage condition has occurred in the Energy Charge Module's Capacitor Modules. This indicates that the capacitor bank is not sufficiently charged or is discharging too rapidly, potentially due to a power supply issue, excessive load on the ECM, or a faulty capacitor module.
Common Causes
- Low voltage detected on the capacitor module (ECM) below P1-75 threshold.
- Inadequate power supply to the ECM.
- Capacitor module (ECM) internal fault causing voltage drop.
- External load drawing excessive current, reducing ECM voltage.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Immediately stop the machine using the emergency stop button and open the external Main Circuit Contactor (MCC) of the Power supply.
- 2
Measure the voltage across the Capacitor Modules (A06B-6158-H020) to confirm the low-voltage condition.
- 3
Verify the input power supply to the ECM for stable voltage and adequate current to properly charge the capacitors.
- 4
Check for any abnormal load connected to the ECM that could cause rapid discharge of the Capacitor Modules.
- 5
Inspect the Capacitor Modules (A06B-6158-H020) for internal faults, such as leakage or degradation, that prevent them from holding charge.