scenario #1
if there is a direct linear chain of 5 residential outlet boxes is it acceptable to tap into one of the boxes in order to run another leg with another 1 or 2 duplex receptacles? if so is it acceptable to take off from the unused terminal screws of the outlet rather than have to redo the existing pigtails?

scenario #2
if there is no convenient existing outlet box to tap into is it acceptable to tap into the wire midway, add a splice/junction box and continue from there with the second leg?
note- the only problem with this is that there is not enough slack in the wire so an additional foot of wire will be required to be spliced to extend to the existing run, meaning another splice box next to the junction box.

thanks for the advice

 

Yes to #1 and #2. As to #1 pigtails are considered slightly more reliable. As to #2, yes two boxes and both must remain assessable. Two Caveats: Ungrounded wiring can not be extended and existing load must be determined before deciding if a new load can be added.

 

Have you calculated the load on that circuit? That's the most important thing.

 

Another thing to consider is if the boxes have enough cubic inch capacity for an additional cable. A larger box might be needed.

 

The wiring in question is for a basement workshop and will be 12ga wire.
The most consistent draw will be six 4ft fluorescent light segments (2 bulbs in each segment) and a radio. Everything else will be intermittent draws, shop vac, power tools, chargers etc.

How would i go about formally calculating the load? And is there a maximum number of outlets permitted per run?

Thanks

 

The NEC does not have a limit on receptacles in a residential setting. The load is determined by the equipment that will be used on the circuit.

 

I'd forget about getting power from the existing circuit and install a new 20 amp circuit since power tools will be used.