Service loops are excess cable (slack) that is designed to be in addition to any cable needed for the actual planned drop (run) length and terminations. Service slack is found at both ends of the permanent link in a structured cabling system. The required length of wire left inside an electrical box is a matter of safety and future maintenance, ensuring that devices can be installed and serviced without complication. This saves time and reduces cost. This loop prevents water from traveling along the cable into. Ideally, wire groups are installed in layers and wires are bent at right angles to buses or breakers. Label short sheathing sections (slugs) to indicate which circuits wires serve. Labeling cables at outlets is important so that when it comes time to attach wires to devices, you'll always know. Am I leaving too much wire as slack? Just doing some outlet roughing in.