NOTE Some non-isolated inverter topologies with a grounded array are technologically possible, but IEC 60364-7-712 requires simple separation between the mains and the PV if the array is grounded. A non-isolated inverter where the only connection of the array to ground is through the mains neutral connection to earth is allowed under IEC 60364-7-712 because the system design does not allow current to flow on grounding conductors under normal conditions (except for expected leakage current), and the functionality of any residual curent detection in the system is not impaired.If the only connection of the array to ground is on the mains side of the inverter automatic disconnection means (through the neutral connection to earth), then the array is considered ungrounded.An inverter for use with an array of decisive voltage classification decisive voltage classification-A is required to use at least reinforced insulation (protective separation) between the array and decisive voltage classification-B and -C circuits such as the mains.For some types of inverters a type B residual curent detection is required. See 4.8.3.4.New information at the time of publication indicates that grounded arrays would benefit from the additional protection offered by the use of array ground insulation resistance measurement before inverter connection to the grid. That added protection feature can significantly reduce the risk of fire hazards on grounded arrays due to ground faults caused by improper system installation, commissioning, or maintenance, leading to undetected first ground faults followed by subsequent additional ground faults. Table 30 above indicates "Not required" for this technique on inverters for grounded arrays, but an IEC 62109-2 amendment is planned for the near future and requirements are under consideration for improved ground fault protection for grounded arrays. At that time IEC 62109-2 will also be coordinated with the system protection requirements in IEC 62548 currently under development.