Deye SUN-18K-SG05LP3-EU-SM2 three-phase hybrid inverter, 18kW

This device is the heart of a solar installation with a battery: it takes the current produced by the panels, turns it into the ordinary current in the sockets and chooses at every moment whether the energy goes to the house, to the batteries or to the grid. Unlike the versions with high-voltage batteries, it works with low-voltage battery banks, of the 48 V type, which are simpler to expand and also accept classic lead batteries, not only lithium. Being three-phase, it suits houses and buildings with a three-phase connection, and the SM2 series can supply the three phases completely unequally, that is you can have the whole load on a single phase without the device stopping.

The 18 kW of continuous power cover the consumption of a large house or of a guesthouse, and in the absence of the grid the inverter can deliver, for 10 seconds, double the rated power, exactly what pumps, compressors and machine tools require at start-up. Up to 28,8 kW of panels fit on the roof, with a maximum voltage of 800 V. The charge and discharge current of 330 A allows fast filling of a large bank of 48 V batteries. The IP65 enclosure resists dust and water jets and can also be mounted on an outside wall, but with 456 x 750 x 268,5 mm and 51,9 kg it is a heavy device, which requires a solid support and mounting by two people. If you already have a photovoltaic installation connected to the grid, this model can be added over it through AC coupling, without redoing the existing system.

Rated AC power 18000 W, three-phase output 3L+N+PE at 220/380 V or 230/400 V (0,85-1,1 Un), 50 Hz (45-55) or 60 Hz (55-65), maximum continuous current 30,0 A, off-grid peak 2 x Pn for 10 s, 100% unbalanced output. PV input: maximum power 28800 W, maximum DC voltage 800 V, two MPPT trackers with a 2+2 string configuration. Lead-acid or lithium-ion battery, range 40-60 V, maximum charge/discharge current 330 A. Maximum efficiency 97,6%, IP65, 51,9 kg, operating temperature -40...+60 degrees C with derating above 45 degrees C; communication WiFi, RS485 and CAN, paralleling up to 10 units both on-grid and off-grid, AC coupling and storage of the energy from a diesel generator.

Who it suits

Suitable for a large home, a guesthouse or a farm with a three-phase connection and a 48 V battery bank, especially where the loads are distributed unequally on the phases or there are motors with a large starting peak.

Terms explained

• Low-voltage battery (48 V): A battery bank that works at a voltage close to that of car batteries; it expands easily by adding modules, but requires thick cables, because a large current passes through them.
• Unbalanced output: The possibility of supplying the three phases with very different consumptions between them, without the device blocking, which matters in a house where most of the sockets are on the same phase.
• AC coupling: The way of adding the battery over an already existing solar installation, connecting it on the house current side, without dismantling what was installed before.

Technical specifications

Recommended applications

• Large homes and guesthouses with a 48 V battery bank
• Three-phase backup with unbalanced loads on the phases
• Farms and workshops with motors that require a starting peak
• Storage retrofit over an existing on-grid installation (AC coupling)

Warranty

5 years standard, 10 years depending on the market

Technical details

Specifications confirmed from the manufacturer's datasheet

Deye SUN-18K-SG05LP3-EU-SM2 is part of the SG05LP3-EU-SM2 series (14-20 kW) and is a three-phase hybrid inverter intended for low-voltage batteries, lithium-ion or lead-acid, with a voltage range of 40-60 V. The maximum battery charge/discharge current is 330 A, a value that allows fast charging of large banks of 48 V batteries.

The photovoltaic side accepts up to 28800 W of PV power, with a maximum DC voltage of 800 V, through two MPPT trackers with a 2+2 string configuration. The rated AC output is 18000 W at 220/380 V or 230/400 V (0,85-1,1 Un, 3L+N+PE), 50 Hz (45-55) or 60 Hz (55-65), with a maximum continuous current of 30,0 A. In off-grid mode, the inverter supports a peak of 2 times the rated power for 10 seconds, useful for starting motors and pumps.

The maximum efficiency is 97,6%. The enclosure has IP65 protection, dimensions of 456 x 750 x 268,5 mm (without connectors and brackets) and a mass of 51,9 kg. The operating range is -40...+60 degrees C, with derating above 45 degrees C.

Communication is done through WiFi, RS485 and CAN. A maximum of 10 units can be connected in parallel, both in on-grid and off-grid mode, and the inverter can store energy coming from a diesel generator. The SM2 series supports 100% unbalanced three-phase output and AC coupling, so it can be combined with existing on-grid photovoltaic installations.