Suggestions on terminating boxes
The procedure I prefer to use is to not "fold" the wiring into the box, but to wind it, similar to a coil spring. It works for solid or stranded conductors.
Before you begin, study the layout of the box, conductors, devices to be installed. Lay the wiring devices out in position near you, so that you can visualize where the connection points need to be, in final placement. Picture in your mind the coiling direction of rotation that would be best suited. Do the wires originate from a similar direction, and help dictate which direction is best? If from multiple directions, which way of winding will introduce the least number of bends "folds" in the wiring? Which direction will end up leaving the best place for the wirenuts to reside without interfering with the space required of the device?
The idea is to give some serious thought to the layout before you begin. The worst method is to strip and cut to length the conductors, make the splices then try to cram it in the box.
Start with the conductors "way longer" than you think you need, don't be cheap here. With the coiling method it is often easier to put more wire in the box than less. Pick one common mode of rotation direction for all the wires. Start by spiral training "wrapping" them into the back of the box, as in their final resting place. On the first wrap, train the wires to rest around the periphery edges of the box. Do at least 1 complete wrap around the box, then consider where it needs to land according to your earlier planned layout. Wrap the "additional" amount it needs to reach is landing point, and leave the excess sticking out of the box. Do this to all of the conductors before cutting any of them to length. At the end of this procedure, all wiring should be nicely coiled in it final resting place at the back periphery of the box. No cramming will be necessary. In fact the opposite will usually will be true. Once trimmed to final length, the wire will need to be pulled out slightly to make the terminations, then just gently move it back to the position where it was originally.
When servicing the installation it's easy to pop the coiled "spring" out of the box, to access the terminations. Less pressure is exerted on the terminations, and the connections when making the final placement of devices, and therefore are less likely to loosen, placing them in the final resting spot.
Place the grounds the furthest back and terminate them first, adding some pigtails for the installed devices and box as required. Then do the neutrals, adding any required pigtails. Tuck the grounds and neutrals into the final resting place, then proceed in the same fashion with the line conductors and wiring devices.
When making the terminations to the devices, only pull out the wiring as little as necessary to make the connection. Then it will naturally have less physical resistance going back to the location it was just in.
Using "pigtails" to feed receptacles from in and out cable connections is good practice. The down stream receptacles wont be dependent on the upstream receptacle screw connections. Downstream devices will only rely upon the splice "wirenut" connection, not on the receptacle termination screws. The NEC requires this for any neutral on a multiwire circuit.
300.13 Mechanical and Electrical Continuity — Conductors.
(B) Device Removal. In multiwire branch circuits, the
continuity of a grounded conductor shall not depend on
device connections such as lampholders, receptacles, and
so forth, where the removal of such devices would interrupt
the continuity.
MTW Ω
