Adding outlet to 220v circuit
Learning as I go, so please forgive me if this is rudementary. I will explain what I need as best I can.
I need to add two new outlets to an existing 10-3 wire 30 amp 220v circuit in my shop. Currently, the circuit only has one outlet on it that is in the wrong area of the shop for my needs.
My plan was to remove the box, pull the 10-3 wire through a sheetrock patch and surface mount a new box, pigtail the outlet to THHN (solid core?) wire then contine the THHN wire through conduit to my new location and new outlets.
However, when I remove the outlet cover and look inside the box , I have the expected orange 10-3 wire going into the outlet , with two unexpected 12-3 lines that are spliced together in the box from a different circuit.
Is it adviseable for me to continue with my plan to surface mount the box and pulll all of the wires into the surface box including the 12-3 splice (if it will even reach); or would it be better (acceptable) to remove the outlet, splice a piece of 10-3 wire to the existing 10-3 wire and fish the new piece of 10-3 above or below the box and through the sheetrock into a surface mounted box , cover the original box with an outlet cover and continue with my plan with only the 10-3 and THHN transition in the surface mounted box?
Sorry if this is not clear. Thanks for any help.
Mike