Thanks to the inner coding key differently shaped between metallic enclosures (trapezoidal cross-section) and insulating enclosures (rectangular cross-section inscribed in the trapeze), connector inserts size “21.21” having a floating PE contact (e.g. CDF/M 07) while for use at voltages higher than SELV (safety extra-low voltage) are prevented to fit into metallic enclosures CKA-MKA, CGK-MGK, as they would not provide the required PE connection to the enclosure. The corresponding outer coding keyway of all “21.21” inserts having the PE contact able to guarantee bonding to earth to the metallic enclosure or of those inserts deemed to be used only at SELV is similarly trapezoidal, thus these inserts fit into all enclosures. Insulating “21.21” enclosures accept all “21.21” inserts.
• Insulating enclosures in self-extinguishing light grey RAL 7035 or jet black RAL 9005 thermoplastic material • metal enclosures in die cast zinc or aluminium alloy, according to model • metal enclosures with epoxy-polyester thermosetting powder coating grey RAL 7040 • gaskets in anti-aging, oil-resistant, grease-resistant and fuel-resistant NBR vinyl nitrile elastomer provided on the • “21.21” male inserts (according to model), glued on some hood models and some cover models, or provided as • flange gasket (according to model) • metallic enclosures with block locking lever in stainless or galvanized steel • insulating enclosures with single-block locking lever in self-extinguishing thermoplastic material (CK-MK)