New EPS product for 3 phase?

[wilks]

I’m a relatively new Fox customer based in the U.K. I currently have a fully working 3-Phase ‘hybrid’ setup composed of 5 x Foxx EP11 batteries, a H3 Pro 15 inverter, and 31 Aiko 450w solar panels each with its own associated Enphase micro inverter.

I would like my setup to be able to switchover and continue to operate fully (‘whole house’ mode) using solar generation and stored battery power, in the event of a full grid outage. I’m aware that you can have a single plug socket or a single mains circuit become live in the event of a full grid outage fairly easily, but I’m seeking auto-cutover for the whole house.

My installer told me at the point of installation that my system could not do this, but that new products were coming out from fox ‘soon’ that could enable this. I spoke with Fox technical support recently who told me that a new product was indeed coming out later this year that will meet my needs, specifically for 3-phase systems. The new product is a ‘EPS BOX PRO-HC’ I’m told.

Is anyone else aware of, or tracking, this upcoming new EPS product?

[MaterialBarracuda48]

Have a read here about the single phase product, there is a delay in switching gear that you might not like
viewtopic.php?p=15407#p15407

[wilks]

Thanks for the link. That is indeed not what Fox infer on their website. I can see (and agree with) your frustration here.

I did spot that a 2-3 second cutover delay would occur even with the new EPS product, which seems unavoidable. I currently have a small UPS that protects my NAS, NUC and Unifi kit which gives me about 10 mins of cover in a power failure (its been tested a few times). The battery in the UPS is quite old now so I could probably move that up to 20 mins with a new battery and/or a larger UPS to protect this most critical equipment. Even with the current UPS in place, I'll be able to accommodate a sub 10s cutover period without issue I think. None of that will protect things like fridges or freezers that are currently wired into the mains, which I've seen first-hand blow during a power cut and restoration. Hopefully the Fox equipment will at least smooth some of that out spikiness out in the power supply.... (he hopes).

[wilks]

for info, here is the data sheet for the upcoming 3-phase EPS that Fox told me about:

https://www.fox-ess.com/Public/Uploads/ ... 250905.pdf

[netsheriff]

3-Phase ‘hybrid’ setup composed of 5 x Foxx EP11 batteries, a H3 Pro 15 inverter, and 31 Aiko 450w solar panels each with its own associated Enphase micro inverter.

I would like my setup to be able to switchover and continue to operate fully (‘whole house’ mode) using solar generation and stored battery power, in the event of a full grid outage.

My installer told me at the point of installation that my system could not do this,

You can run all your back up on auto contactors. You need to spread the load out over the 3 phases as you only have 5kW/phase with a 15kW inverter.

You could do your system with a 4pole 2NO 2NC (below) and a 2pole 1NO 1NC contactors. To cover all 3 phases.
You can run 4 circuits on a 4 pole and 2 on a 2 pole.
On a 4 pole R2 & 2 (combined) go to 2 circuits as do R4 & 4 (combined).
R1 & R3 go to 2 separate EPS ports and 1 & 3 go to the grid.
A1 to Grid L and A2 to Grid N.
Normally power runs from grid 1 and 3 to CBs connected to R2&2 & R4&4.
In a blackout the power it cut to the coil A1 & A2 the contactor will automatically switch to R1 & R3 and thus runs off the EPS. When the power is restored the contactor coil it automatically switches back to the grid.

[nrb501]

Please do NOT consider the solution suggested above for several reasons - use a proper auto transfer switch (ATS) system.

Just five reasons not to consider netsheriff's' suggestion:

• Single phase failure may not be detected, likely resulting in the inverter tripping out or possible back-feed to grid (safety issue)

• Short duration breaks will result in rapid change-over from mains to inverter supplying the load and back likely causing damage to the contactors

• No true detection of out of tolerance of mains voltage, although the contractor coil is nominally rated at 230v its pull-in and drop-out voltages are likely outside the normal tolerance for mains voltages

• Using two contractors in the manner suggested can result in the change-over of all phases not being simultaneous, increasing the likelihood of equipment damage

• An ATS will provide a means to perform a manual change-over if necessary

A proper ATS is not just a dumb relay, it has mechanisms to check for in spec supplies, stop hunting between supplies and check the main supply is stable before reverting to it.