The Fox ESS H3-125-Plus is the flagship model in the H3 Plus commercial hybrid inverter range, delivering 125kW nominal AC power and up to 137.5kVA of output for large commercial and industrial three-phase installations. Built around high-voltage LFP battery storage with 240A max charge/discharge current across three independent battery ports, it combines an 8 MPPT / 250kW PV input with sub-10ms EPS switchover and FoxCloud V2.0 remote monitoring, making it suited to logistics hubs, production facilities, and other sites where continuity of supply is critical.
Qualified Installation Required
This is a high-voltage commercial hybrid inverter operating on 380/400V three-phase supplies with battery voltages up to 950V DC. Installation, commissioning and grid connection must be carried out by a qualified, competent electrician in accordance with local grid codes and wiring regulations.
Battery Compatibility
Compatible exclusively with Fox ESS high-voltage LFP battery stacks, including the CQ16 series, connected across the inverter's three independent battery ports.
100% Unbalanced Three-Phase Output
Each phase can be loaded independently up to full capacity, so uneven commercial loads — common in sites with mixed single and three-phase circuits — don't force the inverter to derate.
Long Backup Capability
With more than 6 hours of backup power available from a fully charged battery stack, the H3-125-Plus keeps critical processes running through extended grid outages rather than just bridging short interruptions.
Sub-10ms EPS Switching
The Emergency Power Supply function switches to backup in under 10 milliseconds, fast enough that sensitive electronic loads and control systems typically ride through the transition without a reset.
Eight Independent MPP Trackers
With 8 MPPTs and 2 strings per tracker, PV arrays can be split across multiple roof orientations or shading conditions without sacrificing harvest, up to 250kW of connected array capacity.
High-Voltage Battery Architecture
Operating across a 180–950V DC battery window with 240A max charge/discharge current keeps conduction losses low even at full 125kW throughput, supporting the unit's 98.5% peak efficiency.
FoxCloud V2.0 Remote Monitoring
Built-in Wi-Fi, LAN, Bluetooth and optional 4G connectivity feed FoxCloud V2.0, giving installers and site managers live visibility across multi-inverter, multi-battery commercial deployments.
| PV Input |
| Max. Array Power |
250 kW |
| Max. Input Power |
250 kW |
| Withstand Voltage |
1000 V |
| Input Voltage Range |
180 – 950 V |
| Max. MPPT Input Current |
40 A |
| Max. MPPT Short Circuit Current |
50 A |
| MPPT Voltage Range |
180 – 850 V |
| Start-up Voltage |
180 V |
| No. of MPP Trackers |
8 |
| Strings per MPP Tracker |
2 |
| Battery Specification |
| Battery Type |
LFP (LiFePO₂) |
| Voltage Range |
180 – 950 V |
| Max. Charging/Discharging Current |
240 A (80+80+80) |
| Battery Ports |
3 |
| Communication |
CAN × 3 |
| AC Output (On-Grid) |
| Nominal AC Power |
125 kW |
| Max. AC Output Power |
137.5 kVA |
| Rated AC Output Current (Per Phase) |
189.9 A |
| Max. AC Output Current (Per Phase) |
198.5 A |
| Nominal AC Voltage |
380/400V, 3W+N+PE or 3W+PE |
| AC Voltage Range |
0.8 ~ 1.2 Un |
| Nominal AC Frequency |
50/60 Hz |
| Frequency Range |
50/60 Hz, ±5 |
| Power Factor |
0.8 leading – 0.8 lagging |
| THDi |
<3% @ Rated Power |
| AC Input |
| Max. AC Input Power |
207 kVA |
| Max. Bypass Current |
300 A |
| Nominal AC Voltage |
380/400V, 3W+N+PE or 3W+PE |
| Frequency Range |
50/60 Hz, ±5 |
| EPS Output (Load) |
| Max. AC Output Power |
155 kVA |
| Peak AC Output Power (10s) |
155 kVA |
| LRA Current |
300 A |
| Nominal AC Voltage |
380/400V, 3W+N+PE or 3W+PE |
| Nominal AC Frequency |
50/60 Hz |
| Switching Time |
<10 ms |
| THDv |
<3% @ Rated Power |
| Efficiency |
| European Efficiency |
98.1% |
| Max. Efficiency |
98.5% |
| Protection |
| DC Input Switch |
Yes |
| Battery Reverse Polarity |
Yes |
| PV Reverse Polarity |
Yes |
| AC Overcurrent Protection |
Yes |
| AC Output Short Circuit Protection |
Yes |
| AC/DC Surge Protection |
Class II |
| ISO Detection |
Yes |
| Residual Current Detection |
Yes |
| Ground Fault Detection |
Yes |
| AFCI |
Yes |
| Terminal Overtemperature Protection |
Yes |
| String Current Detection |
Yes |
| General Specification |
| Dimensions (W×H×D) |
730 × 1060 × 305 mm |
| Weight |
120 kg |
| Operating Temperature |
−30 to 60°C |
| Cooling Method |
Smart air cooling |
| Operating Altitude |
4000 m |
| Humidity |
0 – 100% |
| Noise |
<70 dB |
| Standby Consumption |
<60 W |
| DC-Link EV Charger Ready |
20 – 50 kW |
| Ingress Protection |
IP65 |
| Topology |
Non-isolation |
| Display |
LED, LCD, Wi-Fi+APP |
| Communication Ports |
USB / RS485 / Bluetooth / Wi-Fi+LAN / 4G (optional) / CAN |
Is the Fox ESS H3-125-Plus suitable for outdoor installation?
Yes, it carries an IP65 ingress protection rating and an operating temperature range of −30 to 60°C, making it suitable for sheltered outdoor plant areas as well as indoor plant rooms.
What batteries can I connect to the H3-125-Plus?
The H3-125-Plus is designed for Fox ESS high-voltage LFP battery stacks such as the CQ16 series, connected via its three independent battery ports, each supporting up to 80A charge/discharge current.
How long will the H3-125-Plus power my site during a grid outage?
With more than 6 hours of backup capability from a fully charged battery bank and an EPS switching time of under 10ms, it's designed to maintain continuity for critical commercial loads through extended outages.
Can the H3-125-Plus handle unbalanced three-phase loads?
Yes, it supports 100% unbalanced three-phase output, so each phase can be loaded independently without derating the overall system.
Does the H3-125-Plus support EV charging?
The unit includes DC-Link EV charger readiness for 20–50kW, allowing integration with compatible EV charging infrastructure.
How is the H3-125-Plus monitored remotely?
It connects via Wi-Fi, LAN, Bluetooth, USB, RS485 and optional 4G to FoxCloud V2.0, giving installers and site managers live monitoring across multi-inverter, multi-battery commercial systems.
