Deye SUN-3.6K-G (3.6 kW) - single-phase grid-tie inverter

Who these 3.6 kW are for, and why not 3 or 5

The SUN-3.6K-G sits between the three and five kilowatt models of the series, and the reason it exists is simple: the same compact housing and the same single tracker, but 20 % more power and an array limit of 4.7 kW instead of 3.9. In practice that means one or two extra modules on the same roof — at the same cost for mounting, cable and protective gear. The typical site is a private house or a flat with its own roof that fits nine to eleven panels, a small shop, an office, a coffee bar consuming 10 to 20 kWh during the day. Like every model of the G series this is a grid-tie inverter: it supports no battery and does not operate during a power cut, so backup cannot be obtained from it by design. If riding through outages is the goal, a hybrid is required — the SUN-5K-SG03LP1-EU (item 2050), for example; if the goal is a smaller bill and exported surplus, this model does it with minimal investment.

A single 13 A tracker: why the array becomes one long string

Maximum operating input current per tracker is 13 A with a short-circuit current of 19.5 A, and that is the most important number when designing the array. A modern 550 to 600 W module carries 13 to 14 A of working current, which means two strings in parallel will not work here — the combined current exceeds the limit and the inverter either curtails power or trips. There is exactly one correct arrangement: all panels in series, one string, within the voltage limits. The MPPT window of 70 to 500 V against a 550 V maximum allows ten or eleven modules in a row, and that is how the permitted 4.7 kW array is reached. Start-up voltage is only 80 V, so a short string of three or four panels will run too — handy when the array is extended in stages, though in winter the open-circuit voltage in frost should be checked so it stays well clear of 550 V.

16.4 A output: what changes in the board compared with the 3 kW model

Rated output current is 16.4 A at 220 V and 15.7 A at 230 V, with a maximum reaching 18 A. This is precisely the case where the usual 16 A circuit is no longer sufficient: the cable should be 2.5 mm² and the breaker rated 20 A, otherwise it will trip on a sunny midday with nothing actually wrong. The AC connection uses an IP65 connector, so sealing survives outdoor mounting, and the DC isolator is built into the housing. Apparent power of 3.96 kW means the inverter briefly delivers slightly more than its nameplate, which is normal behaviour on bright reflective days when the array exceeds its rated 3.6 kW. For a site on a feed-in arrangement the meter matters too: bidirectional metering must be installed before commissioning, or energy exported to the grid simply will not be recorded.

97.5 % efficiency and no maintenance at all

Maximum efficiency is 97.5 %, the European figure 97.3 %, tracking efficiency exceeds 99 % and output distortion stays below 3 % — for a grid-tie inverter these numbers mean minimal conversion losses in practice. Cooling is natural: there is no fan whatsoever, and therefore no part that wears, clogs with dust and starts to whine after a few years. Noise does not exceed 35 dB, meaning the unit is audible only with an ear against the case. Night-time self-consumption is under one watt — a few kilowatt-hours a year, so there is no point in switching it off overnight. All maintenance across years of service amounts to checking terminal torque and wiping dust off the housing, because there are no filters and no moving parts here at all.

An installation one person can do

The 280 by 310 by 184 mm housing weighs 4.8 kg, so one person lifts it onto the wall and fixes it without a helper — on small sites that noticeably affects the final installation price. IP65 protection and tolerance of humidity to 100 % non-condensing allow outdoor mounting, though in this climate it usually goes under a canopy or in a hallway next to the board. The operating range of -25 to +65 °C comfortably spans any local winter and summer, although derating begins above +45 °C, so a shaded spot always beats a south wall in full sun. Installation altitude reaches 2000 m with no derating, and panels connect through MC4 connectors. One practical point: the compact case is easy to hang anywhere, but convection needs 15 to 20 cm of free space above and below, otherwise heat accumulates and efficiency falls during the sunniest hours.

Monitoring, protection and certification

Communication comes in four forms at once — RS485, RS232, Wi-Fi and LAN — so connecting the inverter to an app or a metering system needs no additional modules. An LCD 1602 text display on the housing shows instantaneous power, voltage, daily yield and error codes, while detailed statistics live in the mobile app. Protections are standard for a grid-tie unit: earth-fault monitoring, grid monitoring, DC reverse-polarity protection, short-circuit protection and type II surge arresters on both sides. Certification includes IEC/EN 62109-1/2, IEC 61727, IEC 62116, VDE4105, VDE0126, AS4777.2 and CEI 0-21 — the full set for an official connection and operator approval. The warranty is five years, while the real service life of such inverters is usually limited by their electrolytic capacitors, which means the mounting location and thermal conditions affect longevity more than the brand does.

How it differs from its neighbours in this catalogue

The SUN-3K-G (item 2083) is the same housing and the same tracker, but 3 kW with a 3.9 kW array and 13.7 A of output current, so a 16 A circuit suffices for it. The SUN-2K-G (item 2085) is the smaller 2 kW unit with a 2.6 kW array, the logical pick where roof space or consumption is limited. If there are more than 4.7 kW of panels, or the roof has two different planes, the choice should be the SUN-5K-G (item 2086): two independent 13 A trackers, an array of up to 6.5 kW and a mass of 8 kg. For a large array the series offers the SUN-10K-G (item 2068) with two 26 A trackers and up to 13 kW of panels. And once more on the essential point: all these models reduce the bill, but none of them keeps the lights on during an outage — for that the catalogue has a separate branch of SUN-xK-SG hybrids, and the choice between the two families should follow the task, not the power rating.

Tell us how many panels your roof takes and whether you plan to export surplus, and we will work out whether 3, 3.6 or 5 kW is the optimum.