In addition to disconnection from the grid (islanding protection ) on no supply, under and over voltage conditions , PV systems shall be provided with adequate rating fuses, fuses on inverter input side (DC) as well as output side (AC) side for overload and short circuit protection and disconnecting switches to isolate the DC and AC system for maintenance.
Fuses of adequate rating has to be provided in each solar array module to protect them against short circuit.
There could always be possibility of something being wrong with the inverter and it continues to put electricity to the grid in the event of grid failure. In such case to avoid any accident, a manual disconnect switch beside automatic disconnection to grid should have to be provided to isolate the grid connection by the utility personal to carry out any maintenance. This switch will be locked by the utility personal.
Following protections has to be provided to ensure safe and efficient operation :
- Avoiding Battery overcharging (in case of SPV system with battery)
- Avoiding Battery over discharge(in case of SPV system with battery)
- Battery over load protection(in case of SPV system with battery)
- Ground fault protection system.