How to install an "always hot" receptacle into an empty junction box with multiple lines from a switched outlet?

[Sactownhero]

Hi guys, total newb here. I'm hoping for some advice. Here's my situation:

1) I want to install a water softener in my garage where there is currently an unused (solid faceplate) junction box nearby.

2) I removed the solid faceplate and it revealed that there are currently three sets of wires coming into the box (three blacks, three whites, and three copper ground wires). I'm assuming this means this is part of a chained circuit.

3) The chain is from a switched outlet that controls the exterior porch lights. It is only hot when the switch is turned on.

4) I need to keep the current light switch in place, as I use it to turn on and off the exterior porch lights that are also on the same circuit. (I do not wish to mess with the light switch wiring at all.)

5) Is there a way for me to configure the sets of wires in the junction box so I can install an "always hot" outlet (2 plugs) for my water softener system? I only need one of the two outlets to be always hot for the water softener, if that matters.

Appreciate any tips, advice, etc.

 

[LLigetfa]

If the three blacks are tied together, then there is not an always hot feed into the box so not possible to tap in to power the softener. This can be confirmed by checking voltage on each black to see which one brings the voltage to the box and then confirming the voltage is only present when the switch is on.

I assume the three whites are also tied together and that there is not a separate white that has black tape or Sharpie marking to indicate it is not a neutral.

 

[Sponsor]

 

[Sactownhero]

If the three blacks are tied together, then there is not an always hot feed into the box so not possible to tap in to power the softener. This can be confirmed by checking voltage on each black to see which one brings the voltage to the box and then confirming the voltage is only present when the switch is on.

I assume the three whites are also tied together and that there is not a separate white that has black tape or Sharpie marking to indicate it is not a neutral.

(With the switch "on"), only ONE of the three blacks are hot (using a voltage detector). The other two do not register a signal.

 

[LLigetfa]

(With the switch "on"), only ONE of the three blacks are hot (using a voltage detector). The other two do not register a signal.

I assume they were tied together before and you disconnected them for the test. So the one that is hot only when the switch is on, is the source and the other two are the loads.

 

[Jadnashua]

If you do not have a constant hot in that box, then no, you can't put a receptacle there unless you run an additional line(s). Be careful about the box fill number, as adding another cable and then the receptacle might dictate the need for a larger box. It sounds like the wires may be coming in via a conduit, and running new wires through it is also limited by a fill volume.

If the fill volume isn't too great, and it's conduit or EMT, then you may be able to fish the new conductors there, or might need to bite the bullet and an entirely new, separate run. If everything in that box is on the same circuit breaker, you only need one new wire and can tap into the neutral (white) and ground leads to connect a receptacle. You'd have to run a new lead from the hot side of the switch to the box where you want the receptacle, then put the stuff back together with a pigtail on the neutral and ground to the new receptacle, and that constant hot to the hot side of it.