Bluetti split phase can not be called a UPS anymore

I noticed that my 2xAC300’s in split phase no longer work as an UPS. On utility power loss it switches nicely but when utility power gets restored it needs 5 seconds to switch over and during that time you will loose power. Imagine a short 1 second utility power loss will now be a 5 second power loss thanks to the 5 seconds it takes to switch back. I am so shocked. After spending around 20k on this system including the smart home panel. The UPS works well without the split phase in place. But with it calling it a UPS is misleading. Unless you think 5 seconds is short enough to call it ‘uninterruptible’ I don’t. Oh and Bluetti confirmed the 5 sec switch over. So I am not making this up… be warned.

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Hi @BigApple ,
In our models that support split-phase mode (AC300 EP500/PRO AC500),
UPS only supports single-phase mode, in split-phase mode (240V dual firewire) the machine assumes the EPS function.

So, @BLUETTI it would be better to run the two units in single phase with out the combiner and just run into home panel or xfer switch to maintain the UPS function? (this of course assumes the two AC300s are fed by out of phase grid power).

Hi @StingerZ16 , I’m very sorry. Only two hosts can be connected in split-phase mode (single-phase is not supported). In split-phase mode, the machine assumes the EPS function.

@BLUETTI can you give us your definition of EPS function? (I may be wrong that EPS is not “Earnings Per Share”)
I assume @BigApple has rightly titled this as the AC 300 in split phase is NOT an UPS. if so how does marketing get away with saying it has UPS function?

EPS seems to stand for “Emergency Power Supply” not what i had in mind when i spent 20k+ on this stuff. Very misleading for sure.

Hi, Yes, EPS refers to Emergency Power Supply.

I lost power for eight days because Hurricane Fiona hit Puerto Rico last week. I am running fully on the Bluetti setup with PV power. It is a standby system, not a UPS under split phase, and I am okay with the five second switchover. Before this setup, I ran a gasoline powered generator, and that took minutes to setup, startup, and transfer. Now I don’t have to transfer at all or use my generator, and I have a separate 40 A 240 VAC breaker circuit charging my Bluetti setup when there is little or no solar power.

The reason I asked for ht meaning of EPS is because it is not well defined by the industry.
@BLUETTI how does Bluetti define the operation of an EPS?
I, and other my have an idea, but I would like to know how Bluetti defines it.
I also know how what a UPS is. it is well defined. AC300 is advertised as an UPS not an EPS.
This difference will determine how best to deploy and use an “EPS”

This is a good example of why we are all using Bluetti Power.

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Thank you for the approval. My utility power returned, but I am still powering my home with the Bluetti setup. I have to buy two more B300 batteries to cover my needs on cloudy days since we are still in hurricane season.

EPS and UPS operate on similar principles, except that the switching time of EPS is longer than that of UPS.

There is a more important difference. A true UPS will not let the load lose any power, so you can trust vital electric, electronic, and network devices to continue operating without interruptions. The EPS is like an external secondary power source such that after the regular utility power is lost, the secondary power source kicks in, such as a fuel powered generator set, which I also have.

Under this arrangement, you have to add true UPS systems to your vital applications. In my case, I have real UPS power sources for my two TV and cable sets, and for my WiFi router and security camera controller, since a power loss and return causes a reboot that takes too many seconds to recover. My home computer is a laptop so it has its own UPS built in.