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Off-grid inverter

EG4 12000XP / 15000XP Off-Grid

A third code scheme from the same manufacturer: errors are E-prefixed, warnings W-prefixed, status codes hexadecimal. The status LED tells you which table to read — green is normal, yellow a warning, red a fault. Note E019 trips on PV above 495 V while E021 trips above 480 V; both mean the string is too long.

Faults — the unit stops (24)
E000. Fault. Internal communication fault between the microprocessors.
Check first
  1. Full power cycle: battery, PV, and AC down, then back up in order.
  2. If it returns, it is a board fault. Open a ticket with the distributor rather than resetting repeatedly.
E001. Fault. The unit is reporting an invalid model value to itself.
Check first
  1. Restart. Persistent means the unit goes back — nothing field-serviceable.
E003. Fault. CT failure. Internal current-transformer sampling error.
Check first
  1. Restart. If it persists, contact the distributor.
E008. Fault. CAN communication error in a parallel system.
Check first
  1. Reseat the grey parallel cable in the correct ports at both ends.
  2. Set the CAN termination DIP to ON at the first and last inverter only, OFF for everything between.
E009. Fault. No master in the parallel system.
Check first
  1. Exactly one inverter is Master. A single-unit system must still be set correctly.
  2. Check the parallel setting on every unit.
E010. Fault. More than one master set in the parallel system.
Check first
  1. Two units are both claiming Master. Keep one, set the rest to Slave, power-cycle the group.
E012. Fault. Do not just reset. Off-grid short circuit on the Load or Smart Load output.
Check first
  1. Power down before touching anything.
  2. Open the load breaker. If the fault clears with the load disconnected, the short is downstream in the subpanel.
  3. Reversed L and N at the load terminals reads as a short.
E013. Fault. UPS reverse current. Power is flowing backwards into the load terminal.
Check first
  1. Confirm nothing is backfeeding the LOAD side — a generator or second inverter on the wrong terminal will do this.
  2. Restart. If it persists with the load side dead, contact the distributor.
E014. Fault. Do not just reset. Internal DC bus short circuit. Hardware.
Check first
  1. Do not keep resetting this. Shut down and call the distributor.
E015. Fault. Phase error in a three-phase parallel system.
Check first
  1. Each phase needs at least one inverter. Verify the AC connection matches the configured phase on every unit.
E016. Fault. Relay fault. An internal transfer relay failed its self-test.
Check first
  1. Restart once. A relay that will not pass self-test is a return, not a repair.
E017. Fault. Internal communication fault 2.
Check first
  1. Verify all firmware finished updating. Power off three minutes, restart.
E018. Fault. Internal communication fault 3.
Check first
  1. Verify firmware is current on both processors. Power off three minutes, restart.
E019. Fault. Do not just reset. Bus voltage too high. EG4 points at PV input above 495 V.
Check first
  1. Note the difference from E021: this trips at 495 V, that one at 480 V. Both mean your string is too long.
  2. Open the PV disconnect, measure Voc on every string cold.
  3. If the array is off and it still faults, look at the battery side before blaming PV.
E020. Fault. Do not just reset. LOAD connection fault. Grid and load terminals appear swapped.
Check first
  1. Trace both terminal blocks before re-energizing. Grid feeds GRID, subpanel lands on LOAD.
  2. Getting this backwards can energize the wrong side of the system.
E021. Fault. Do not just reset. PV voltage too high — above 480 VDC. This is the fault that kills inverters.
Check first
  1. Open the PV disconnect first.
  2. Measure Voc on every string with the array cold, first thing on a winter morning.
  3. Recalculate maximum modules per string against the site's record low. A string legal at noon can be illegal at sunrise.
  4. Damage from exceeding the limit is not covered under warranty.
E022. Fault. Hardware-level overcurrent protection tripped.
Check first
  1. Power off three minutes, restart. Repeated hardware trips mean the unit goes back.
E023. Fault. Do not just reset. Neutral fault.
Check first
  1. Find the neutral-to-ground bond. There must be exactly one, at the first service disconnect.
  2. The 12000XP can create the bond internally via N-PE Connect — but it is not dynamic, so it is either always on or always off. Two bonds is a fault.
  3. A bonded portable generator or RV plug will do this.
E024. Fault. Do not just reset. PV short circuit.
Check first
  1. Open the PV inputs. Ring out each string for a positive-to-negative short and a conductor-to-ground short.
  2. A pinched conductor under a rail or a wet, unseated MC4 is the usual culprit.
  3. If it faults with all strings disconnected, the unit is bad.
E025. Fault. Internal temperature out of range.
Check first
  1. Shut down for ten minutes and restart.
  2. Check the manufacturer's clearances and get the unit out of direct sun.
  3. Clear debris from the heatsink and air filters; confirm the fans spin.
  4. T1 (I/O board) faults at 95 °C; T2 (motherboard) at 105 °C. Both are readable in the Data menu, Other tab.
E026. Fault. Internal fault. The bus and PV readings are not physically consistent.
Check first
  1. Restart. Persistent means the unit needs service.
E028. Fault. Sync signal lost in the parallel system.
Check first
  1. Confirm the CAN parallel cable is in the correct ports on every unit.
  2. All inverters in the group must be on matching firmware.
E029. Fault. Sync trigger signal lost in the parallel system.
Check first
  1. Use the supplied parallel cable in the correct COM port.
  2. Verify DIP switch configuration, then restart the group.
E031. Fault. Internal communication fault 4.
Check first
  1. Confirm every firmware update completed. Power off three minutes, restart.
Alarms — it may keep running (24)
W000. Alarm. Battery communication failure. The inverter falls back to guessing SOC from voltage, which on a flat LFP curve is nearly useless.
Check first
  1. Check the RJ45 pinout end to end, and that the cable is in the right port — CAN and RS485 are not interchangeable.
  2. Confirm the correct Lithium brand is selected. On this manual revision, EG4 batteries use Lithium type 1; LifePower4 V1 and RS485 use 0.
  3. The comm cable lands on the master battery, not a slave.
W001. Alarm. The inverter lost communication with its arc-fault module.
Check first
  1. Restart. If it does not clear, you are running without arc-fault protection until it is serviced.
W002. Alarm. Do not just reset. AFCI high. An arc fault was detected on the PV side.
Check first
  1. Do not clear it and walk away. An arc fault is a fire in progress somewhere.
  2. Measure Voc and Isc on every string and compare against expected.
  3. Inspect every MC4 on the roof — an unseated connector or a cross-mated pair from two brands is the overwhelming cause.
  4. Only then clear the fault, via Application settings, PV Arc Fault Clear.
W003. Alarm. Meter communication failure.
Check first
  1. Check the meter comm cable and that the meter is powered. Restart.
W004. Alarm. Do not just reset. Battery BMS fault. Comms work, but the BMS itself is reporting a problem.
Check first
  1. Restart the battery and verify the comm cables.
  2. Look at the battery's own indicator. If the BMS is faulting, this is a battery problem, not an inverter problem.
  3. Cold blocks LFP charging below freezing, exactly as it should.
W006. Alarm. Rapid shutdown is active. This is the system doing its job.
Check first
  1. Check whether the RSD or E-Stop button is pressed or latched.
  2. With EG4 batteries in closed-loop comms, RSD also triggers the ESS Disconnect, so the battery drops too.
W007. Alarm. The LCD cannot talk to the M3 microprocessor.
Check first
  1. Restart. The inverter may still be running correctly behind a dead screen — check Monitor Center.
W008. Alarm. Firmware mismatch between the microprocessors.
Check first
  1. Re-run the update from the first task. A partial update leaves the processors out of step.
  2. Never interrupt a firmware update.
W009. Alarm. A cooling fan is stuck.
Check first
  1. Kill power and look for debris, a wasp nest, or a seized bearing.
  2. A stuck fan becomes E025 under load. Fix it before summer.
W011. Alarm. Stack overflow in the control firmware.
Check first
  1. Restart. Persistent means the unit needs service.
W013. Alarm. Over temperature. The unit is approaching its limit but has not faulted yet.
Check first
  1. This is the warning before E025. Act on it now.
  2. Check clearances, air filters, and fans. Get the unit out of the sun.
  3. T1 warns above 87 °C, T2 above 90 °C.
W014. Alarm. More than one master set in a parallel system.
Check first
  1. Keep one Master. Set the rest to Slave and power-cycle the group.
W015. Alarm. Do not just reset. Battery reversed.
Check first
  1. Stop. Open the battery disconnect before anything else.
  2. Red to BAT+, black to BAT−. Cross-polarity damages the unit and voids the warranty.
W017. Alarm. AC voltage outside the operating range.
Check first
  1. Measure the grid at the terminals.
  2. On a generator, check the AVR. Consider APL input range (90–280 V) instead of UPS (170–280 V).
W018. Alarm. AC frequency outside the operating range.
Check first
  1. Measure grid frequency. On a generator, fix the governor or widen the window.
  2. Generator THD must be under 3% or the inverter may not accept it at all.
W019. Alarm. AC inconsistent across a parallel system.
Check first
  1. Every inverter in parallel must be fed from one common AC source.
  2. Restart. If it persists, the AC wiring differs between units.
W020. Alarm. Do not just reset. PV isolation low. Insulation resistance protection tripped.
Check first
  1. Look for damaged conductor insulation and wire pinched under racking.
  2. Check that module frames and racking are properly bonded.
  3. Get conductors out of standing water. This is a shock hazard, not a nuisance trip.
W022. Alarm. DC injection into the AC output is too high.
Check first
  1. Restart. Persistent DC injection is a hardware fault and a compliance problem.
W025. Alarm. Do not just reset. Battery voltage nearing the high limit.
Check first
  1. Measure the pack. High DC cutoff is 59 V for lithium, 60 V for lead-acid.
  2. Check charge voltage settings against the battery manufacturer's numbers, not the inverter defaults.
  3. A BMS that has stopped balancing will push one cell group high.
W026. Alarm. Do not just reset. Battery voltage nearing the low limit.
Check first
  1. Measure the pack. Lithium range is 46.4–60 V; lead-acid 38.4–60 V.
  2. Check the discharge cutoff and warning voltage settings.
  3. A deeply discharged LFP pack may need the BMS woken before it accepts charge.
W027. Alarm. Battery open. The inverter cannot see a battery.
Check first
  1. Check the battery breaker and any DC fuse or disconnect.
  2. Measure the pack with a meter at the inverter terminals.
  3. Bring batteries up one at a time, master first, about five seconds apart.
W028. Alarm. Inverter overload. Running beyond maximum output.
Check first
  1. Total up what is actually on the LOAD panel. Continuous is 12 kW at 240 V, 6 kW line-to-neutral.
  2. Motor inrush is the usual trigger — a soft start is cheaper than a bigger inverter.
  3. In parallel, check the discharge current limit: the 250 A default is for a single inverter and will throttle the system.
W029. Alarm. Inverter output voltage high.
Check first
  1. Look for a device causing surges on the load side. Restart.
W031. Alarm. Too much DC component on the load output.
Check first
  1. Restart. Persistent means the unit needs service.
Status — not a problem (15)
0x00. Status. Standby. Powered but not inverting.
Check first
  1. Normal. If you expected output, check the EPS switch.
0x02. Status. Firmware updating.
Check first
  1. Do not interrupt. A partial update throws W008.
0x04. Status. PV on-grid.
Check first
  1. Normal.
0x08. Status. PV charge. Solar charges the battery only, capped by the battery's charge power.
Check first
  1. Common when the EPS switch is off.
0x0C. Status. PV charge on-grid. Solar powers the load first, surplus charges the battery.
Check first
  1. Normal.
0x10. Status. Battery on-grid. Battery supplies the load; the grid makes up any shortfall.
Check first
  1. Normal.
0x11. Status. Bypass. Grid alone feeds the load; solar goes only to the battery.
Check first
  1. Also shown when the unit is in a fault state. If you did not expect bypass, check for an active fault.
0x14. Status. PV and battery on-grid.
Check first
  1. Normal for AC First or AC Charge windows.
0x19. Status. PV charge plus bypass. Grid feeds the loads, solar goes only to the battery.
Check first
  1. Normal.
0x20. Status. AC charge. Grid powers loads and charges the battery at once.
Check first
  1. Normal.
0x28. Status. PV and AC charge together, grid carries the load.
Check first
  1. Normal.
0x40. Status. Battery off-grid. Grid is down, battery carries the load alone.
Check first
  1. Normal during an outage with no sun.
0x80. Status. PV off-grid. Grid is down, solar carries the load.
Check first
  1. Output follows the sun. Expect flicker under cloud with no battery.
0x88. Status. PV charge off-grid. Solar feeds the load and charges the battery.
Check first
  1. Normal.
0xC0. Status. PV and battery off-grid together.
Check first
  1. Normal. Surplus solar charges the battery.
Source: EG4 12000XP user manual, v1.1.1, sections 15.1-15.2 and 11.2. Firmware and manual revisions change these tables. Confirm against the manual for the unit in front of you before you act.