Deye SUN-10K-SG04LP3-EU (10 kW) - three-phase hybrid inverter

A three-phase 10 kW hybrid: the sites it belongs on

The SUN-10K-SG04LP3-EU is the smallest three-phase hybrid in this catalogue, and the main reason to choose it over a single-phase ten-kilowatt unit is not power but the nature of the load. A three-phase output is needed wherever 380 V motors are present: a borehole or drainage pump, a circular saw or planer in a workshop, a compressor, a hoist, a cold room, a grain mill, a feed mixer. Such motors cannot run from a single-phase inverter at all, and through phase converters they lose both power and service life. The second typical reason is an existing three-phase service: load spreads evenly across the phases, cable currents are a third of the single-phase equivalent, and a house using 20 to 25 kWh a day runs without overheating its wiring. What this model does not do: it is a low-voltage unit with a 48 V battery, so high-voltage banks of the BOS-G or GB-L families cannot be connected — for those the catalogue offers HP3 models such as the SUN-15K-SG01HP3-EU-AM2 (item 2058).

A 48 V battery at 210 A in a three-phase system

The battery bus here is low voltage: 48 V nominal, a 40 to 60 V working range and charge and discharge current up to 210 A, which is about 10.7 kW — precisely what the inverter can deliver to the load. The low-voltage architecture has a practical advantage: 51.2 V batteries are cheaper, the catalogue is full of them (SE-F5 item 1944, SE-G5.1 item 1947, RW-F10.2 item 1930), and a bank can start with one module and grow later. The price is high current: 210 A calls for 70 mm² cable, a 250 A battery breaker and careful terminations, because at that current every poor contact becomes a heat source. To actually reach 210 A you need at least two 120 A modules in parallel: a single module caps the system at roughly 6 kW, and that cap stays invisible until the load grows. AGM and GEL banks are supported too, but for daily cycling in a three-phase system that is plainly a compromise, worthwhile only when the batteries are already on site.

Two unequal trackers: 26 and 13 amps

The photovoltaic side here is asymmetric, and that matters for the design: the first MPPT takes two strings at 26 A of operating current (up to 34 A maximum), the second one string at 13 A (up to 17 A). So the array is divided roughly two to one rather than in half — six to eight panels on the second tracker, twelve to sixteen on the first, for example. Total array power reaches 13 kW against the inverter's 10 kW rating, the 30 % oversizing intended for winter and overcast days. The MPPT window is 200 to 650 V with an 800 V maximum input and start-up from 160 V: this is already a high-voltage PV input, so strings are long, fourteen to eighteen modules, and the cable from the roof can be thinner than in low-voltage systems. Rated PV voltage is 550 V, the point where conversion is most efficient, and tracking efficiency is 99.9 %.

A 20 kW ten-second peak and how power splits across phases

Apparent power is 11 kW, and in island mode the inverter holds 20 kW for ten seconds — double the headroom, enough to start a three-phase pump or compressor even with the system already loaded. But there is a three-phase subtlety people often discover after installation: ten kilowatts are divided across three phases, roughly 3.3 kW per phase. If all the heavy single-phase consumers — water heater, kettle, space heater — sit on one phase, that phase overloads first while the other two idle. Redistributing single-phase circuits across the phases in the board is therefore a mandatory part of installing a three-phase hybrid, not an optional extra. Three-phase motors, by contrast, draw power symmetrically and make an ideal load for such a system; harmonic distortion stays below 3 %, and below 1.5 % on linear loads.

25 A of transit per phase: a limit worth calculating

Maximum grid input current is 25 A, the lowest figure among the three-phase hybrids in this catalogue: about 17 kW of pass-through across three phases. While the grid is up the house can consume more than the inverter itself produces, but not without limit — on a site with an electric boiler or a large workshop that ceiling is easy to feel. For comparison, the larger SUN-15K-SG05LP3-EU-SM2 (item 2060) offers 70 A of transit per phase, three times the margin. The practical conclusion: if the whole house is to pass through the inverter, 25 A per phase means heavy loads deserve a separate line bypassing it. And if only essentials go onto the backed-up circuit — boiler, pumps, lighting, fridges, internet — then twenty-five amps is ample, and that is the most common arrangement.

Mounting, cooling and noise

The 422 by 658 by 281 mm housing weighs 36.8 kg and mounts on solid masonry; lifting it takes two people and a rail fixed in advance. Cooling is forced — the fan allows full power in hot weather, but it is a moving part worth blowing out once a year, particularly in a boiler room with fuel dust. The quoted noise level is below 30 dB, which for 10 kW is very quiet: the inverter is inaudible from the next room, though the fan does become noticeable under sustained load. IP65 protection permits mounting under a canopy, the operating range is -25 to +60 °C and the PV side connects through MC4 connectors. The BMS link runs over RS485 or CAN, so the inverter works from the actual state of charge rather than a voltage estimate — which for a low-voltage bank carrying large currents is fundamentally important.

How it differs from its neighbours in this catalogue

Its closest relative is the SUN-12K-SG04LP3-EU (item 2054) in the same housing at the same weight, but with 12 kW, an array of up to 15.6 kW and 240 A of battery current: once simultaneous load approaches ten kilowatts the step up is justified. The next level is the SUN-15K-SG05LP3-EU-SM2 (item 2060): 15 kW, two symmetric 36 A trackers, an array of up to 30 kW, 70 A of transit per phase and 280 A of battery current — but 51.9 kg of mass and noise up to 60 dB. A fundamentally different architecture is HP3: the SUN-15K-SG01HP3-EU-AM2 (item 2058) works with a 160 to 700 V high-voltage battery at only 37 A, so its cables are thinner, but the battery costs more and a control box is required. And if you have no three-phase service, the comparison should be with the single-phase SUN-10K-SG02LP1-EU-AM3 (item 2059): the same rating and three trackers, but all the load on one phase and no three-phase motors at all.

Tell us which three-phase equipment you have and what your peak load amounts to, and we will advise whether ten kilowatts suffice and which battery will unlock them.