The Italian Standard CEI 0-21:2012-06
The new Italian standard CEI 0-21:2012-06 brings some major changes regarding the use of solar inverters.
The new standard CEI-0-21:2012-06 replaces the standard CEI 0-21:2011-12 effective July 1, 2012 and is binding for all PV systems that are commissionend after July 1, 2012.Due to the new edition of the standard, rules enter into force that have an effect on the use of Delta solar inverters. The standard divides PV systems into categories based on the feed-in capacity:
- PV systems with Pn ≤ 6 kW
- PV systems with Pn > 6 kW and ≤ 10 kW
- PV systems with Pn > 10 kW
PV systems with Pn ≤ 6 kW
These PV systems are connected to a single-phase grid. With inverters that are used in such PV systems, the use of an internal SPI protection is permissible; an external SPI protection is not according to standard. With simultaneous use of an internal and external SPI protection, they must be set in such way that they do not counteract each others proper functioning.
Single-phase PV systems with Pn > 6 kW ≤ 10 kW
PV systems > 6 kW are normally designed as 3-phase systems. However, with the permission of the grid operator, a PV system can also be designed as a single-phase system. The use of an external SPI protection is according to standard; an SPI protection integrated in the inverter must not be used. If an inverter has an integrated SPI protection, it must be switched off.
3-phase PV systems with Pn > 10 kW
These PV systems are always connected to a 3-phase grid. The use of an external SPI protection is according to standard; an SPI protection integrated in the inverter must not be used. If an inverter has an integrated SPI protection, it must be switched off.