Brand u. Ex.-Schutz
ExNB 00-055-CS Cables ends or cables between parts of apparatus tor types of protection other than intrinsic safety
VdTÜV
Technisches Dokument
ExNB 00-127-CS EN 50014:1977 Clause 22.4.3 and EN 50014:1992 clause 23.4.3, Guards for Light Transmitting Parts