While many standards don't specify exact lengths, a common practice is to allow 300–600 mm of spare cable. This extra length provides flexibility during commissioning and maintenance and can significantly reduce downtime and cost if re-termination becomes necessary. Copyright © 2008 by the Institute of Electrical and Electronics Engineers, Inc. In the 2020 NEC ®, no. Particularly, it has been recently amended the standard of cable entry/exit from 'Ex d' junction boxes, whether for IIB or IIB + H2 or IIC group. The updated Standard is the IEC 60079-14/EN. This document deals with cables trays, cables and connector installation and segregation, cable trays earthing and E. These rules shall be applied in the cabling engineering workflow for all subjects concerning or in relationship with cabling in the ITER facility. Not respecting. At least 150 mm (6 in.