Fox ESS EPS 3-Phase Backup Box (EPS-3PH-4UNIT)

Fox ESS EPS 3-Phase Backup Box (EPS-3PH-4UNIT)

The Fox ESS EPS-3PH-4UNIT is a dedicated three-phase emergency power supply (eps) / backup gateway that keeps your property powered during grid outages. Designed for Fox ESS three-phase hybrid inverters, it automatically switches between grid and backup power for a seamless supply when you need it most.

Looking for single phase? Please see the Fox ESS EPS-BOX-SP by clicking here.

⚡ Whole-site backup with up to 80 A per-phase capacity in a rugged IP65 enclosure.

Key Features of the Fox ESS EPS-3PH-4UNIT

• Whole-site backup – automatically powers your home during grid failure
• Fast, seamless switching – flips between grid and off-grid without perceptible downtime
• High power handling – supports up to 80A per phase input current
• Wide compatibility – works with Fox ESS H3, H3 Smart and AIO three-phase inverters
• Durable build – IP65-rated metal enclosure for indoor or outdoor installation
• Easy installation – compact, wall-mounted design

Technical Specifications

• Model: EPS-3PH-4UNIT (3-Phase)
• Frequency: 50 / 60 Hz
• Maximum Input Current (per phase): 80A
• Maximum Output Current (per phase): 80A
• Ingress Protection: IP65
• Cooling: Natural convection
• Operating Temperature: −25°C to +50°C
• Dimensions (W × H × D): 336 × 306 × 138 mm
• Weight: 7kg
• Installation: Wall-mounted

Compatibility

✅ Compatible with Fox ESS three-phase hybrid inverters – H3, H3 Smart, AIO
❌ Not for single-phase inverter systems

Reliable Three-Phase Backup

The EPS-3PH-4UNIT isolates your property from the grid during an outage and maintains power from your solar and battery system across all three phases. When the grid returns, it reconnects automatically and resumes normal operation.

Product Code: EPS-3PH-4UNIT
*EPS Box only. Inverter, batteries and accessories sold separately.

Fox ESS Integrations

Earn extra from your Fox ESS battery

Axle Energy runs a free Virtual Power Plant (VPP) that works with Fox ESS batteries and inverters. It occasionally exports energy from your system to support the grid - and pays you for taking part.

• £25 signup bonus when you join via our link
• £10/month minimum earnings guaranteed
• £1 per kWh exported during events

Earn £10/month & join the Axle VPP

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Downloads

Datasheet – Fox ESS EPS-3PH-4UNIT
User Manual – Fox ESS EPS-3PH-4UNIT

Fox ESS 3-Phase EPS Compatability Guide

Video – Join the Solar Revolution