Grid outages and anomalies are the number one reason CTs become miscalibrated. Auto-detect home limiter sensors can also be tricky. When CTs reverse polarity incorrectly and TOU SOC indicates the battery should still cover the whole home, the inverter overcompensates sending more battery power pulses on the leg the external CT is reporting grid import power. These pulses result in stepped up voltage attempting to charge a single grid leg, causing a voltage spread between L1 and L2 voltages. This can also interfere w the voltage waveform and potentially messes with the phase angle causing simulated frequency distortion resulting in grid disconnects.
Recommendations before performing auto detect:
- Turn off grid sell (if applicable)
- Switch to limited power to load (resets external CTs to read positive grid import polarity, if external CTs show reverse polarity in Limited Power Power to Load, you have them installed wrong)
- non-backup loads must be demanding some power
- Lower TOU battery power to only cover a portion of the load (not full load, this keeps CTs showing grid import power, helps build a reference point for CT calibration)
- Then switch back to limited power to home when ready and quickly run Auto Detect Home Limiter sensors
Once complete and observe if whole home load is greater than critical load alone. Inverter should still say some grid power being imported if whole home loads are greater than the battery power in the TOU setting
Then revert your TOU settings back to normal and enable grid sell (if applicable if allowed to backfeed).
Assuming CTs are in the correct location facing the correct direction, if it’s still not working (assuming it worked before), perform factory reset.
Note: performing auto-detect too many times in a row can scramble memory registers. Factory reset is generally used to correct this.