Overview

Intrabuilding splices are generally constructed in equipment rooms (ERs), telecommunications rooms (TRs), main terminals, entrance facilities (EFs), and cable trays. Cable splice locations and other splicing details are usually specified by the telecommunications distribution designer in work order prints. These work order prints must be strictly followed because the splicing work could affect future cabling system plans. Where questions arise concerning cable pair counts or specific splicing methods, seek direction from the immediate supervisor. For the purpose of this section, the cable splicing techniques described are for in-building applications using single sheath cable (yet to be activated) and fire-retardant 25-pair connector modules in a two-bank, in-line configuration.

Intrabuilding copper cable splicing is allowed only in backbone cable never for horizontal cable (horizontal cable extends between the TR and the work area [WA]). Backbone cables usually have expanded polyethylene-polyvinyl chloride (PVC) insulation and will normally be communications media riser (CMR) rated.

CMR cable consists of 24 AWG [0.51 mm (0.020 in)] copper conductors enveloped by a core wrap and an overall corrugated shield and may be bonded to a fire-retardant sheath. A fire-retardant sheath is required by the National Electrical Code (NEC ) to mitigate the spread of fire from floor to floor. The insulated cable, commonly known as plastic insulated conductor (PIC) cable, is designed for ease of cable pair identification. PIC cable is bundled in 25-pair color-coded binder groups with color-coded pairs in each binder (see colorcode chart in Table 7.1 for cable sizes up to 600 pairs).