Fox ESS 3-Phase Auto Grid-To-Backup Power Switching Box
Fox ESS 3-Phase Auto Grid-To-Backup Power Switching Box additional 1Fox ESS 3-Phase Auto Grid-To-Backup Power Switching Box additional 2

£166.66 ex VAT£199.99 inc VAT

Out of Stock

If you would like to be emailed when this product is back in stock, please enter your email address below.

Product features

  • Seamless backup power switching
  • Compatible with Fox ESS inverters
  • Works with battery systems
  • Automatic 3-phase backup switching
  • Robust IP65 metal enclosure
  • Indoor or outdoor installation
  • Compact, lightweight design
  • Installer-friendly wall mounting
Product code: 3PH-4UNIT
Feefo badgeFeefo Gold Trusted Service Award
Description

The Fox ESS EPS 3PH-4UNIT 3-Phase Automatic Backup Switching Box works with a battery and inverter system to seamlessly transition to automatic backup power during grid failures. It's a high-performance, three-phase emergency power supply solution designed to ensure your solar-plus-storage system never misses a beat. Engineered for both residential and light-commercial installations, it guarantees consistent power stability for essential loads when continuity matters most.

Built with reliability at its core, this robust EPS unit switches effortlessly between grid and backup modes, maintaining smooth operation across all three phases without the need for manual intervention. Its durable IP65 metal enclosure provides long-lasting environmental protection, making the unit suitable for indoor plant rooms as well as exposed outdoor locations.

Optimised for integration within the Fox ESS ecosystem, the EPS 3PH-4UNIT pairs perfectly with the brand’s leading three-phase inverters, including the H3, AIO H3, and H3 Smart series. Compact, lightweight, and naturally cooled for silent operation, the unit offers installers and end-users a future-ready backup solution that is easy to fit, dependable in all conditions, and engineered for long-term resilience.

With flexible voltage compatibility, high current capacity, and reliable performance across temperatures from –25 °C to +50 °C, this three-phase EPS box is tailored for those who require dependable energy security without compromise. The EPS box does not supply power by itself, it switches power from the inverter/battery system to the home or building during an outage.

  • Automatic Three-Phase Backup Switching: Seamlessly transitions to backup power during outages, ensuring essential loads remain energised across all phases
  • Robust IP65 Weatherproof Enclosure: Tough metal housing provides complete protection from dust & water, suitable for indoor or outdoor wall-mounting
  • Optimised for Fox ESS Inverters: Designed to integrate quickly & cleanly with Fox ESS H3, AIO H3 & H3 Smart inverter systems
  • Compact, Lightweight & Installer-Friendly: Streamlined dimensions & wall-mount design enable fast, straightforward installation with minimal disruption
  • Silent, Fan-Free Cooling: Natural cooling ensures quiet operation & long-term durability with fewer moving parts
  • High-Performance Electrical Capability
    • Voltage compatibility: 220/380 VAC or 230/400 VAC (3L/N/PE)
    • Grid input current: up to 80 A per phase
    • EPS input current: up to 20 A per phase, organised into four circuits
    • EPS load output: up to 80 A per phase
  • Built for Extreme Conditions: Reliable operation from –25 °C to +50 °C, ideal for varying UK climates
  • Dimensions (W*H*D): 336mm x 306mm x 138mm | Net Weight: 6kg

Why It Exceeds Expectations

  • Security in Any State: Whether grid-connected or off-grid, the EPS 3PH‑4UNIT ensures critical loads stay powered with fast, automatic switching.
  • Built to Last: Reliable IP65 construction ensures durable performance in a variety of environments - from dusty garages to exposed outdoor walls.
  • Future-Ready Flexibility: Made to align with Fox ESS hybrid inverters, this backup box supports upgrades and system expansion with ease.
  • Installer-Centric Design: Compact dimensions, lightweight body, and simple mounting make setup hassle-free - without compromising on safety or scalability.

Code: 3PH-4UNIT

DELIVERY INFORMATION

Fast, reliable UK delivery

  • FREE UK delivery (2–3 working days) on orders over £99 exVAT (order before 4pm)*.
  • Orders under £99 exVAT are charged £6 inc VAT (£5 exVAT).
  • Need it quickly? Choose from our Next Working Day & Saturday delivery options below (order before 2pm).

Delivery options & rates

Delivery OptionDelivery TimeCost
Standard Delivery2-3 working days£6.00 (£5.00 exVAT)
FREE Standard Delivery (orders over £99 exVAT)*2-3 working daysFREE
Next Working Day Delivery (order before 2pm)Next working day£9.99 (£8.33 exVAT)*
Next Working Day by 12pm  (order before 2pm)Next working day£20.00 (£16.67 exVAT)
Next Working Day by 10:30am  (order before 2pm)Next working day£21.60 (£18.00 exVAT)
Saturday Delivery  (order before 2pm Friday)    Next working day£20.00 (£16.67 exVAT)
Northern Ireland, Highland  & Islands Delivery  3-5 working days£9.99 (£8.33 exVAT)

Important: Orders placed after 2pm on Friday (or over the weekend) are processed on Monday for next working day delivery. Next Day & Saturday Delivery options NOT available on all products.

*FREE Standard & Next day delivery available on select products and will be clearly shown on the product page.


What to expect

  • We dispatch Monday - Friday (excluding public holidays).
  • Once dispatched, you’ll receive tracking information (where available).
  • If delivery is delayed for any reason, we’ll contact you as soon as possible with an updated estimate.

Please note: we cannot be held responsible for missed deliveries. Customers are advised to check their spam or junk folder to ensure tracking information and estimated delivery details are received.


Specialist product delivery

Some products require specialist handling:

  • For Portable power please allow up to 4 working days for delivery.
  • Solar panels are shipped via our £100 pallet delivery service.
  • In some cases a third-party supplier may fulfil your order directly.

Delivery areas & restrictions

  • Northern Ireland, Scottish Highlands & Channel Islands: please contact us for shipping rates.
  • Portable power to Northern Ireland: we can’t currently ship these items due to insurance issues with the courier.
  • International delivery: unfortunately we do not currently offer international shipping.

Questions, problems, or returns?

RETURN POLICY

Last updated May 23, 2024

Thank you for your purchase, we hope you are happy with it.

However, if you are not completely satisfied with your purchase for any reason, you may return it to us for a full refund, store credit, or an exchange; please see below for more information on our returns policy.

RETURNS

If you find you have received the wrong or damaged item(s), you need to contact us within 7 days of receipt of goods. Any time after this you are responsible for returning the goods at your own cost following the standard returns process.

All returns must be postmarked and in writing within fourteen (14) days of the purchase date. All returned items must be in a new, unopened and unused condition, with all original tags and labels attached.


RETURN PROCESS

To return an item, please click the ‘Download Returns Form’ below and complete all data fields. You can then email this to our team once completed.
Place your item(s) securely in its original packaging along with the returns form.
Please note that the RMA# on the returns address is your original order number; please ensure to reference this on the returns address, as per below.
You are now ready to mail your return to the following address:

Attn: Returns
RMA #/Order No -
Eco WizardUnderfloor Wizard Ltd t/a ECO Wizard
Beechfield House
Winterton Way
Macclesfield
Cheshire
SK11 0LP
United Kingdom

We ask that all customers when returning products send the goods via a trackable courier service. Underfloor Wizard Ltd t/a ECO Wizard will not be held responsible for goods which do not arrive at our premises.

Please note, you will be responsible for all return shipping charges, unless in the instance of damaged/faulty goods received in which case we can issue you with a returns label to cover the cost of postage.

Download Returns Form

REFUNDS

After receiving your return and inspecting the condition of your item, we will process your return or exchange. Please allow at least seven (7) days from the receipt of your item to process your return or exchange. Refunds may take 1-2 billing cycles to appear on your credit card statement, depending on your credit card company. We will notify you by email when your return has been processed.

Faults on installed products: 

If a product that has been installed develops a fault, please contact us, do not uninstall the product yourself. We will arrange for an engineer or technical support from the brand to assist with diagnosing the fault. Once the fault has been confirmed we can then arrange for the necessary next steps to occur.


EXCEPTIONS

The following items cannot be returned or exchanged:

  • opened box, damaged, missing or incomplete items cannot be returned.
  • items that have been installed.


QUESTIONS
If you have any questions concerning our return policy, please contact us at: returns@ecowizard.co.uk

Reviews