FoxESS H3/AC3 three-phase hybrid & AC-coupled error codes explained

The master sample detection circuit is failed.

What you can do

• Note the code, then restart the system once using the owner shutdown/start-up steps in your manual
• If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Residual current detection device is failed.

What you can do

• Keep clear and do not touch the inverter or cabling
• Note the code, date and time
• Call a licensed electrician or Total Solar - this alarm means current may be leaking to earth

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The inverter eeprom is fault.

What you can do

• Note the code, then restart the system once using the owner shutdown/start-up steps in your manual
• If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The PV connection is reversed.

What you can do

• Do not touch the DC isolators, cables or connectors
• Call your installer - this points to a wiring problem that needs a licensed electrician

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The battery relay keeps open.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The battery relay keeps close.

What you can do

• Turn off any very large loads that were running when the alarm appeared
• Wait - many over-current protections reset automatically
• If it keeps happening, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The battery buck circuit mosfet is fail.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The battery boost circuit mosfet is fail or The relay on the battery side of the inverter is not closed. To upgrade to the latest software, at least ensure that the master is upgraded to 1.69 or above.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The eps relay is failed.

What you can do

• Turn off some large appliances (air-conditioners, ovens, kettles, pool pumps) - backup outputs have a power limit
• The system usually recovers by itself once the load drops
• If it keeps happening with normal loads, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The battery connection is reversed.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The grid relay keeps open or close.

What you can do

• Turn off some large appliances (air-conditioners, ovens, kettles, pool pumps) - backup outputs have a power limit
• The system usually recovers by itself once the load drops
• If it keeps happening with normal loads, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The communication between master and slave is fail.

What you can do

• Check that your home Wi-Fi/internet is working and restart your router
• Wait an hour - monitoring often reconnects by itself
• If the inverter screen also shows a fault, or the alarm stays for more than a day, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The slave sample detection circuit is failed.

What you can do

• Note the code, then restart the system once using the owner shutdown/start-up steps in your manual
• If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The manager eeprom is fault.

What you can do

• Note the code, then restart the system once using the owner shutdown/start-up steps in your manual
• If the code comes back, call your installer - this is an internal fault that needs a licensed electrician or the manufacturer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The communication between meter and inverter is interrupted.

What you can do

• Check the monitoring app for the alarm and whether export/consumption readings look wrong
• Restart your home router if the meter talks over Wi-Fi or LAN
• Call your installer - meter and CT wiring is inside the switchboard and must be checked by a licensed electrician

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The communication between BMS and inverter is interrupted.

What you can do

• Check the app - the battery may show as offline or with no state of charge
• Restart the system once using the shutdown and start-up steps in your owner's manual (battery last off, first on, unless your manual says otherwise)
• If the alarm comes back, call your installer - battery communication cables must be checked by them

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The communication between BMS and inverter is interrupted.

What you can do

• Check the app - the battery may show as offline or with no state of charge
• Restart the system once using the shutdown and start-up steps in your owner's manual (battery last off, first on, unless your manual says otherwise)
• If the alarm comes back, call your installer - battery communication cables must be checked by them

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

DIP switch at the wrong position; The communication between battery packs is interrupted.

What you can do

• Check the app - the battery may show as offline or with no state of charge
• Restart the system once using the shutdown and start-up steps in your owner's manual (battery last off, first on, unless your manual says otherwise)
• If the alarm comes back, call your installer - battery communication cables must be checked by them

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery over voltage.

What you can do

• Note the code and the battery state of charge shown in the app
• Let the system run - some battery voltage protections clear by themselves after charging or discharging
• If the alarm stays or keeps returning, call your installer - don't open or disconnect the battery yourself

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery under voltage.

What you can do

• This normally means the battery is low or has reached its reserve level
• Let the system recharge from solar or the grid - check the state of charge in the app
• If the battery never charges or stays at 0% for more than a day of sunshine, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery charge over current.

What you can do

• Turn off any very large loads that were running when the alarm appeared
• Wait - many over-current protections reset automatically
• If it keeps happening, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery discharge over current.

What you can do

• Turn off any very large loads that were running when the alarm appeared
• Wait - many over-current protections reset automatically
• If it keeps happening, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery over temperature.

What you can do

• Check from a safe distance for heat, swelling, hissing, a burning smell or smoke - if you notice any, keep everyone away and call 000
• If nothing looks wrong, make sure the battery area is shaded and ventilated and nothing is stacked against it
• Let the battery cool; most units recover by themselves
• If the alarm keeps returning, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery under temperature.

What you can do

• Check from a safe distance for heat, swelling, hissing, a burning smell or smoke - if you notice any, keep everyone away and call 000
• If nothing looks wrong, make sure the battery area is shaded and ventilated and nothing is stacked against it
• Let the battery cool; most units recover by themselves
• If the alarm keeps returning, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The capacities of cells are different.

What you can do

• This is usually caused by the mains supply, not the solar system
• The inverter normally reconnects by itself once grid voltage is back in range
• If it happens often (especially on sunny afternoons), note the times and call your installer - they can check the voltage and settings and talk to the network if needed

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery hardware under protection.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Bms hardware circuit fault.

What you can do

• Check that your home Wi-Fi/internet is working and restart your router
• Wait an hour - monitoring often reconnects by itself
• If the inverter screen also shows a fault, or the alarm stays for more than a day, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery insulation fault.

What you can do

• Do not touch the panels, rooftop isolators or DC cables
• Note the code and whether it appears in wet weather or early morning - this helps the electrician
• If it clears by itself once things dry out, still let us know if it keeps returning
• Call a licensed electrician or Total Solar - insulation and earth faults need testing with proper equipment

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery voltage sensor fault.

What you can do

• Note the code and the battery state of charge shown in the app
• Let the system run - some battery voltage protections clear by themselves after charging or discharging
• If the alarm stays or keeps returning, call your installer - don't open or disconnect the battery yourself

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery temperature sensor fault.

What you can do

• Check from a safe distance for heat, swelling, hissing, a burning smell or smoke - if you notice any, keep everyone away and call 000
• If nothing looks wrong, make sure the battery area is shaded and ventilated and nothing is stacked against it
• Let the battery cool; most units recover by themselves
• If the alarm keeps returning, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery current sensor fault.

What you can do

• Turn off any very large loads that were running when the alarm appeared
• Wait - many over-current protections reset automatically
• If it keeps happening, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

Battery relay fault.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The capacity of battery packs is different.

What you can do

• Note the code and the battery state of charge shown in the app
• Let the system run - some battery voltage protections clear by themselves after charging or discharging
• If the alarm stays or keeps returning, call your installer - don't open or disconnect the battery yourself

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The software between slaves are different.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The cell manufacture is different.

What you can do

• Note the code and the battery state of charge shown in the app
• Let the system run - some battery voltage protections clear by themselves after charging or discharging
• If the alarm stays or keeps returning, call your installer - don't open or disconnect the battery yourself

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The slave software and hardware are not match.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

The software between Master and Slave are not match.

What you can do

• Check the battery status and any extra alarms in the app
• Restart the system once using the owner shutdown/start-up steps in your manual if it allows
• If the alarm comes back, or the battery is hot, swollen, noisy or smells, keep clear and call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code

No action for charging request.

What you can do

• Check whether the rest of your house or street has power, and check your network operator's outage map
• Check the switchboard for a tripped solar/inverter breaker - reset it once only; if it trips again, leave it off and call an electrician
• Once normal power is back the inverter usually reconnects on its own within a few minutes
• If the power is normal but the alarm stays, call your installer

H3/AC3 three-phase hybrid & AC-coupled · Guide only. All work must be done by a licensed electrician. Get help with this code