The usual reading is that a split-phase inverter is a single-phase inverter with a different output voltage. The label names less than that. Split-phase is still single-phase, but 120/240 V names only the AC output form, and three further requirements travel with it that the voltage figure does not mention.
The belief, and why it survives
The belief survives because the output voltage is the only difference visible from outside. A 230 V single-phase inverter and a 120/240 V split-phase inverter each produce one alternating waveform, and a split-phase unit splits that waveform around a neutral to give two 120 V legs whose difference is 240 V. The two legs are not two phases, and calling them phases is the first sign that the requirement has been read as a voltage rather than as an interface. Comparing the two forms on the same basis means comparing line-to-neutral voltage rather than line-to-line. A 230 V single-phase service presents 230 V from one live conductor to neutral, while a split-phase service presents 120 V from either leg to neutral and 240 V between the legs; the 240 V figure describes the two legs against each other, not a higher class of supply.
Where it breaks: one label, four requirements
The published specification states these figures as of 2026-10.
The fourth row is the one that changes a design. A neutral has to be carried so that 120 V circuits exist at all, and the 120 V loads then divide across the two legs. The page publishes a total power rating of 8 to 15 kW depending on model and publishes no per-leg figure, so a house whose 120 V loads concentrate on one leg cannot be checked against the page as it stands. When the two legs carry unequal load, the total rating stops being the binding figure and the page cannot settle which leg binds; that is a scope gap in the published data rather than a typo.
The DC class is where the label misleads most
Nothing in the words split-phase or 120/240 V says what the battery side accepts. Across the inverter pages published for this line, four different windows appear:
The published specification states these windows as of 2026-10.
The lowest voltage any of the four accepts is 100 V. A wall-mounted battery at 51.2 V nominal sits entirely below every one of those windows, so the split-phase label on its own says nothing about whether the battery on the same quotation connects at all.
The same page does not agree with itself on this point. The title of the split-phase product page contains 48V, while the body text and the specification table on that same page both state 100-400 V DC high voltage. Both readings are published on one page, and a quotation built from the title alone describes a different DC class from the one the specification table describes. The reconciliation step is a written confirmation from the supplier of the acceptable DC window for the exact model, not a choice between the two published figures. If a quotation is written from the title line, the DC class it describes is not the class the specification table describes, and the difference is a battery that does not connect rather than a battery that underperforms.
A certification claim needs a model scope, not a site scope
The split-phase page declares UL 1741, UL 9540, FCC and IEEE 1547. Ruibit's certification page lists CE, CE-EMC, CE-LVD, IEC 62619, MSDS and UN 38.3, and does not list a UL mark at all. Both statements are published, and they are not the same statement: one is attached to a model, the other is a site-level list.
The correct form is therefore that the model page declares those certifications. That is not evidence that a mark covers the site, the family, or the exact configuration being ordered. The reconciliation step is the certificate number together with the model range it covers, in writing.
What follows from treating the label as the whole requirement
An order written from the output description can arrive as a different DC class than the one planned, can be quoted against a per-leg limit nobody published, and can carry a certification expectation the certificate does not cover. Each of those surfaces at commissioning rather than at quotation, and the first cannot be resolved by a setting. The distinction between a voltage difference and a requirement set is also why the same power electronics can be offered into a 230 V market as a two-wire product without meeting the split-phase requirement at all.
What to confirm before ordering
Ask for the acceptable DC voltage window of the exact model in writing, and treat the 48V and 100-400 V statements on that page as unresolved until the supplier reconciles them. Ask for the per-leg limit if one exists, and for the neutral arrangement, since neither is published.
Ask for the certificate number and the model range it covers rather than the certification name. Ask whether the service at the property is actually split-phase, and take the answer from the service rather than from the appliance list.
Two items cannot be reversed once the equipment is ordered. The DC voltage class is the first, because a battery below the accepted window is not brought into range by a setting. The listing scope is the second, because an interconnection approval follows the model and the certificate that covers it.
At handover, record the DC window the supplier confirmed in writing, the certificate number with its model range, and the per-leg limit as applicable. Those three lines are what a utility review or a warranty claim will be checked against.
FAQs
1. Is split-phase the same as two-phase?
No. A split-phase supply is still single-phase: one alternating waveform is split around a neutral to give two 120 V legs whose difference is 240 V. Calling those legs two phases is the first sign that 120/240 V has been read as a voltage rather than as an electrical interface.
2. Does a split-phase inverter accept the same batteries as a single-phase one?
Not necessarily, and the output label says nothing about it. The battery windows published across this inverter line run from 100-400 V on the split-phase model to 150-700 V on the three-phase model, so the DC class has to be checked per model rather than inferred from the AC description.
3. The split-phase product title mentions 48V, but the table says 100-400V. Which is right?
Both readings are published on that same page and the conflict is unresolved, so neither can be treated as settled. The correct step is written confirmation from the supplier of the acceptable DC window for the exact model being ordered.
4. Does the split-phase page's UL listing cover the whole site?
No. The model page declares UL 1741, UL 9540, FCC and IEEE 1547, while the site certification page lists CE, CE-EMC, CE-LVD, IEC 62619, MSDS and UN 38.3 and no UL mark. A model-level claim should be verified by certificate number and the model range it covers.
5. Why does the per-leg question matter for a 120/240V house?
Because the 120 V loads divide across two legs, and the split-phase page publishes a total rating of 8 to 15 kW without a per-leg figure. If most 120 V loads sit on one leg, a limit on that leg can bind before the total rating is reached, and the published page cannot settle the question.
