On the Job 8.16.16

 Today on the job, we encountered an eight wire system on a commercial visit to a client..
That eight wire system was connected to what is known as a plug-and-play shown below.

The former receptacle from the plug-and-play blew out and malfunctioned.
The old one was immediately removed carefully from live at the box from the wall.

 When voltages were checked all voltages read on each of the wires 15 V. That is, except for the black wire which was 125 V . Using two parts of a circuit breaker finder. The circuit breaker that ran from this was easily able to be found through deduction and observation  initially after voltages were checked wire nuts were placed on them (spliced the wires). The lights would turn on from the plug-and-play but the receptacle read 15 V. After using the circuit breaker finder in order for the receptacle and the lights to word  pink wire that ran to the lights was united with the hot wire or black wire that return to the receptacle in this parallel connection both could receive power.  In this way the pink and black wires that energized their respective receptacles and lights. In this way both received power from the black wire that came from the panel. with the exception of the pink wire that came from the panel (capped alone in the picture at the bottom of this post*) The hot black wire from the panel was spliced with the pink and black wires that lead to the plug & play and via said plug & play to the lights. all other wires were spliced with same colors.

Circuit breaker finder 2 parts one for the wires and one for the panel. the alligator clips were clipped to the prongs and a signal (low voltage) was placed on it. The other part shown above was used in the panel to find the circuit.

Wire colors and initial voltage readings:
Initially 15v for everything, but later it was,  Gray 3v, Pink 13v, red 14v, blue 18v, black 125v and of course white was a #10 neutral and everything else was #12. White was larger to handle a load on all of the wires.

Above are the designations for the different wires.

 

(On the right one pink wire that leads back to the panel was capped alone.*)

The left is the arrangement before and the right is after. After the circuit breaker was found the only way to have the receptacle and the lights work was to receive power parallel the pink wire is for the lights and was spliced (wire-nutted) with the black hot wire so both the lights and the receptacle could receive power.