The Fox ESS EPS Box Pro-HC is a three-phase automatic changeover box that lets a compatible Fox ESS hybrid inverter and battery system keep your property powered during a grid outage. When the grid fails it automatically switches the load to the inverter EPS output, and when the grid returns it switches back to the utility supply, so a whole home back up setup needs no manual intervention.
Built for both residential and commercial solar and storage installations, it supports up to 63A per phase and is housed in a robust IP65-rated metal enclosure with simple wall-mounted installation. It is compatible with selected Fox ESS AIO-H3, H3, H3 Smart, H3 Pro, P3-S and P3 Pro inverter ranges.
63A
Max current per phase
3-Phase
230/400 V, 3L/N/PE
-25 to +60°C
Operating range
17 kg
Net weight, wall-mounted
Safety and regulatory
Installation must be carried out by a competent, qualified electrician in line with BS 7671 and Part P where applicable. Isolate all supplies before opening the enclosure, and always connect the protective earth (PE) conductor. Follow the wiring diagram for your specific inverter in the manufacturer installation manual.
Compatibility and load limits
Only use with the Fox ESS inverter ranges AIO-H3, H3, H3 Smart, H3 Pro, P3-S, P3 Pro. In backup mode the connected load must not exceed the EPS output rating of your inverter, even though the box itself is rated to 63A per phase. Check the current specification in your inverter manual when sizing the backed-up circuits.
Not a UPS
Like any automatic changeover device, the EPS Box Pro-HC has a short transfer period when the grid drops. Keep critical equipment such as servers or medical devices on a dedicated UPS.
Key features
Automatic on-grid / off-grid changeover
Detects the grid state and automatically switches between grid and inverter EPS supply, restoring grid supply when the outage ends.
Whole home backup capable
Supports up to 63A per phase on the utility supply, inverter grid, inverter EPS and load connections, for larger homes and light commercial sites.
IP65 metal enclosure
A robust IP65-rated metal enclosure gives dust-tight, water-jet protection for demanding installation environments.
Wide Fox ESS compatibility
Works with selected AIO-H3, H3, H3 Smart, H3 Pro, P3-S and P3 Pro three-phase inverters.
Easy wall-mounted installation
Wall-mounted, naturally cooled design with a compact 550 x 420 x 138.5 mm footprint and a net weight of 17 kg.
RS-485 meter interface
Includes an RS-485 meter communication interface for integration with the inverter, plus a wide -25 to +60°C operating range (derating applies from 45°C).
Technical specifications
General
Type
Three-phase automatic changeover box
Compatible inverters
AIO-H3, H3, H3 Smart, H3 Pro, P3-S, P3 Pro
Enclosure
Robust metal enclosure
Utility supply
Rated voltage
220/380 V AC, 230/400 V AC, 3L/N/PE
Max. input current (per phase)
63 A
Inverter grid
Rated voltage
220/380 V AC, 230/400 V AC, 3L/N/PE
Max. input current (per phase)
63 A
Inverter EPS
Rated voltage
220/380 V AC, 230/400 V AC, 3L/N/PE
Max. input current (per phase)
63 A
Load
Rated voltage
220/380 V AC, 230/400 V AC, 3L/N/PE
Max. output current (per phase)
63 A
Communication
Mechanical and environmental
Installation
Wall-mounted
Operating temperature range
-25 to +60 °C (derating at 45 °C)
Dimensions (W x H x D)
550 x 420 x 138.5 mm
Packing dimensions (W x H x D)
660 x 515 x 235 mm
Frequently asked questions
Which inverters is the EPS Box Pro-HC compatible with?
It is designed for selected Fox ESS three-phase inverters: AIO-H3, H3, H3 Smart, H3 Pro, P3-S and P3 Pro. Always confirm your exact inverter model and firmware requirements before ordering.
What is the maximum current it can handle?
The box is rated for 63A per phase on the utility supply, inverter grid, inverter EPS and load connections. During a power cut, the usable backup power is also limited by the EPS output of your inverter.
Does it provide whole home backup?
Yes, it is suitable for whole home back up where the total load is within both the 63A per phase rating and the inverter EPS output. If your inverter cannot support every circuit, back up essential circuits only.
Is it a UPS? Will devices stay on with no interruption?
No. It is an automatic changeover device, so there is a brief transfer when the grid fails. Equipment that cannot tolerate any interruption should be fitted with its own UPS.
Can it be installed outdoors?
It has an IP65-rated metal enclosure, giving dust-tight and water-jet protection. It is wall-mounted and should be fitted on a suitable solid wall following the manufacturer installation manual, with adequate clearance around it.
Who should install it?
A qualified electrician familiar with BS 7671 and the requirements for backup and islanded supplies. Wiring for the load, grid and EPS connections must follow the manufacturer wiring diagram for your inverter.
