Support Centre for Installers

A photovoltaic (PV) solar system is comprised of solar panels, racks for placing the panels on your roof, electrical wiring and an inverter. From sunrise to sunset, the solar panels generate electricity (DC) which is sent to an inverter. The inverter converts the DC electricity into alternating current (AC), which is the type of electricity required for household use. The AC power is delivered directly to your home’s main electrical service panel for use by you and your family.

With a string inverter there is a single point of failure. If the string inverter fails, the entire array is offline. However, with a microinverter each individual PV module has its own dedicated inverter. If the microinverter (or the associated PV module) should fail. only that PV module is offline while the remainder of the system continues to operate.​ Enphase microinverters have a publicly stated defect rate of 0.05%, which equates to 1 in 2000. Given that the Enphase defect rate is better than most string inverters, this results in a PV installation with higher reliability and a higher overall system uptime over the life of the array.

Additionally, Enphase microinverters have an estimated useful life of more than 25 years, compared with string inverters that typically last around 10 years.

If the microinverter (or the associated PV module) should fail, only that PV module is offline. The remainder of the system continues to operate as normal – a key benefit of AC modules.​

The Enphase three-phase Q Cable allows balanced and automated power management of each phase. Alternatively, when using three single-phase cables, care must be taken to balance the phases by installing a similar number of panels on each phase.

The Envoy-S communications gateway can also provide phase imbalance monitoring to ensure authorised limits are not exceeded. The Envoy is able to manage PV power production at the microinverter level to maintain balance within set limits.

In single-phase, 10 microinverters can be connected. In a three-phase installation, up to 30 microinverters can be connected on a single 20A three phase circuit breaker. Larger systems can be constructed with multiple AC branch circuits.

No, export limiting functionality is not yet compliant with RD 244/2019. Most installations with Enphase microinverters are residential scale (below 15kW) and are easily accepted without this compliance.​

Each microinverter is a single phase device. Three-phase installations are constructed with single phase microinverters distributed across the phases. The inverter will monitor power consumption at each phase using the CTs connected to the Envoy-S communications gateway, limiting grid export to the defined level, either on a per phase or aggregate basis as required.​In three-phase installations, can you divide surpluses by phases?