P3 overload - if eps box pro would fix my problem
Posted: Sun Jan 18, 2026 10:17 am
Hello,
My current PV installation is a FoxESS P3 hybrid inverter (10kW model) with 2x EP11 batteries (total ~20kWh), connected to a 6.37kWp on-grid PV array. The whole house is wired directly to the EPS output terminals of the inverter without any EPS Box – all circuits (kitchen, heating, EV charger, etc.) run through EPS, causing frequent phase overloads (>3.5-4kW per phase). Inverter is set to Self Use mode: priority PV > Battery (above Min SOC-OnGrid 30%) > Grid. Currently on-grid continuously, house draws from battery when SOC allows, but overloads trigger EPS shutdown/restart (AutoRec enabled), leading to blackouts. Question to FoxESS community/experts: Will adding EPS Box Pro (3-phase, 63A) help achieve default on-grid operation with battery priority usage (Self Use), maximizing self-consumption from battery while avoiding full 100% discharge? I know EPS Box won't fix overloads themselves (that's inverter power limit), but how to configure so house uses mixed sources – e.g., max 3.5kW per phase from battery + remainder from grid automatically?Currently, when load spikes > inverter EPS capacity (~10kW total), it fully cuts battery discharge and blacks out. Want: continuous on-grid base + partial battery contribution (capped per phase) without exceeding limits. Possible via EPS Power Limit settings, Discharge Current Limit per phase, Grid Support thresholds, or scheduler rules in Fox Cloud app? Setup details:3-phase house, unbalanced loads (kitchen L1 heavy)Min SOC-OnGrid: 30%, no Grid Charge periodsFrequent OL during winter evenings (heating + cooking)Fox Cloud app shows Power Flow switching, but need stable mixed Grid+Battery. Will EPS Box enable smoother Grid fallback during high loads while maintaining Self Use priority? Schematics/settings examples appreciated.
If it would work: ongrid with eps box (while self use on grid add Booster from battery until the soc end) after battery is empty it will be 100% on grid.
How about when discharging battery possibility all the time overload, what will happen when battery discharge will cause overload, will my AC all the time works despite this from ongrid? I cannot understand this but service in Poland tells me that will be good with box.
Thanks!
My current PV installation is a FoxESS P3 hybrid inverter (10kW model) with 2x EP11 batteries (total ~20kWh), connected to a 6.37kWp on-grid PV array. The whole house is wired directly to the EPS output terminals of the inverter without any EPS Box – all circuits (kitchen, heating, EV charger, etc.) run through EPS, causing frequent phase overloads (>3.5-4kW per phase). Inverter is set to Self Use mode: priority PV > Battery (above Min SOC-OnGrid 30%) > Grid. Currently on-grid continuously, house draws from battery when SOC allows, but overloads trigger EPS shutdown/restart (AutoRec enabled), leading to blackouts. Question to FoxESS community/experts: Will adding EPS Box Pro (3-phase, 63A) help achieve default on-grid operation with battery priority usage (Self Use), maximizing self-consumption from battery while avoiding full 100% discharge? I know EPS Box won't fix overloads themselves (that's inverter power limit), but how to configure so house uses mixed sources – e.g., max 3.5kW per phase from battery + remainder from grid automatically?Currently, when load spikes > inverter EPS capacity (~10kW total), it fully cuts battery discharge and blacks out. Want: continuous on-grid base + partial battery contribution (capped per phase) without exceeding limits. Possible via EPS Power Limit settings, Discharge Current Limit per phase, Grid Support thresholds, or scheduler rules in Fox Cloud app? Setup details:3-phase house, unbalanced loads (kitchen L1 heavy)Min SOC-OnGrid: 30%, no Grid Charge periodsFrequent OL during winter evenings (heating + cooking)Fox Cloud app shows Power Flow switching, but need stable mixed Grid+Battery. Will EPS Box enable smoother Grid fallback during high loads while maintaining Self Use priority? Schematics/settings examples appreciated.
If it would work: ongrid with eps box (while self use on grid add Booster from battery until the soc end) after battery is empty it will be 100% on grid.
How about when discharging battery possibility all the time overload, what will happen when battery discharge will cause overload, will my AC all the time works despite this from ongrid? I cannot understand this but service in Poland tells me that will be good with box.
Thanks!