Variant 1 STANDARD CEI 20-91
Electric cables with halogen-free, flame-retardant elastomeric insulation and sheath for use in photovoltaic systems.
The most important part of the variant states:
This Standard applies to cables with insulation based on G21 rubber quality (HEPR) under a halogen-free, flame-retardant M21 elastomeric sheath. These cables are of the non-flame propagating, halogen-free type and can be used for applications in photovoltaic systems, suitable for both DC up to a voltage of 1,800 V, or AC up to a maximum voltage of 1,200 V.
Cables covered by this Standard can be used at a maximum voltage of 1800 V in direct current, also towards ground.
Therefore, all SOLAR ENERGY FG21M21 cables CAN BE USED UP TO 1800V DC, including towards ground.