Delta has introduced two new string inverters, M15A Flex and M20A Flex, which are designed for use in residential and commercial photovoltaic (PV) systems. The two inverters are part of the Flex series, and they use the same design philosophy as the M70A Flex. The M15A Flex inverter is a 16.5 kVA three-phase inverter with two maximum power point trackers (MPPTs) suited for residential installations. The product features a maximum efficiency of 98.3 per cent and a European efficiency rating of 97.9 per cent. The dimensions of the product are 651x520x220 mm, and it weighs 40.5 kg. The device has input voltages ranging between 200 and 1,000 VDC, with a nominal voltage of 600 V. The maximum voltage that it can withstand is 1,100 VDC. The M15A Flex can function at temperatures ranging from -25 to 60 degrees Celsius and at an altitude of up to 4,000 metres. It also features IP66 protection.
The second inverter, M20A, is a 22 kVA three-phase device that is of the same size and weight as the M15A Flex and is also equipped with two MPPTs. The product has an efficiency level of 98.5 per cent, and its European efficiency reaches 98.1 per cent. The input voltages and the nominal voltage are the same as the M15A inverter. Both products include arc fault detection, reverse polarity protection and a built-in anti-potential induced degradation mechanism. Reportedly, Delta’s M15A and M20A Flex are fan-less designs and are cooled only by natural convection, which makes them ideal for quiet, low-noise residential and small commercial buildings. Both products come with a five-year guarantee.