Retrofit of inverters according to Italian standards CEI 0-16 and CEI 0-21

Changes in the standards CEI 0-16 and CDI 0-21 require firmware updates for some Delta inverters

Photovoltaic plants are currently installed in Italy having a totally capacity exceeding 15 GW. With the introduction of CEI 0-21 and CEI 0-16, the range of frequency and voltage in which the plants can remain in operation was expanded. The purpose of this expansion is to support the network in question in the event of momentary disequilibria and to promote return under rated conditions. The disconnection from the network of a large quantity of distributed generators, such as the photovoltaic plants, tends to destabilize the national network. To avoid the possibility of the inverters disconnecting prematurely, in plants with external Interface Protection Systems (IPS), the integrated protections must be configured compatibly with that of the external (IPS). This means that the integrated protections must be more permissive or set to the maximum with the same external protection thresholds.

These rules have been introduced by the appendix to the external network code A70 and subsequently required by the standards:

  • CEI 0-21 for the low voltage network
  • CEI 0-16 for the medium voltage network

This nevertheless also regards existing plants, connected to the medium voltage network, having a power rating greater than 50kW, and placed in service before March 31, 2012. Resolution number 84 of 2012 of the Authority for Electrical Energy and Gas (AEEG) establishes in article 5 the dates by which these plants must be updated. The producer, in addition to updating the inverters and the protection systems, is also obligated to sign a new implementing regulation and complete the update by March 31, 2013. The inverters, in order to satisfy article 5 of the resolution, must conform to paragraphs 5 and 8, excluding 8.1.1, of appendix A70. For this purpose, the producer of the inverter will have to provide a notarized substitute declaration attesting to the conformity.  

The updating procedures can be differentiated with respect to the inverter in question; the modalities for the various inverters can be seen in the table below: 

Inverter model Update only by the authorized installer Update only by the Delta assistance service Period for entry in force
G2 Delta SI2500 EOE45010009 2006 – 03/2012
Gaia GRID 3 EOE45010137
Gavazzi ISG131 EOE45010010
Tenesol GRIDFIT 2500 EOE45010011
Delta SI3300 EOE46010011
Gaia GRID 4 EOE46010127
Gavazzi ISG140 EOE46010012
Tenesol GRIDFIT 3300 EOE46010013
Delta SI5000 EOE46010016
Gaia GRID 6 EOE46010147
Gavazzi ISG160 EOE46010017
Tenesol GRIDFIT 5000 EOE46010018
G3 Delta SOLIVIA CS 44-66 EOE98030256
Delta SOLIVIA CM 77-100 EOE98030176
Delta SOLIVIA 2.5 EU G3 TR EOE4501026 2009 – 03/2012
Delta SOLIVIA 3.0 EU G3 TR EOE46010266
Delta SOLIVIA 3.3 EU G3 TR EOE46010190
Delta SOLIVIA 5.0 EU G3 TR EOE46010201
Delta SOLIVIA 15 EU G3 TL EOE48010223
Delta SOLIVIA 20 EU G3 TL EOE48010224