Hello Pat.........my name is XXXXX XXXXX X will be happy to assist you with your electrical question. My goal is to exceed your expectations on Just Answer!
1) Can you visually trace the old circuit from the breaker panel in the basement to the exterior of the house? Any chance that there is a splice box in between or are both circuits a "homerun" back to the main panel??
2) How are you able to measure 110VAC, from an existing hot to a neutral or from an existing hot to a ground? Are you sure you are not measuring voltage from the other circuit and possibly not the 2 hot's from the 50 amp breaker?
3) Doubt that the old circuit had a neutral wire, usually just 2 hot's and 1 ground wire?
4) Have you looked inside the main electrical panel to make sure there are no double taps on the 50 amp breaker? Any splices inside the panel or do the 2 hot's land directly on the 50 amp breaker?
5) What are you using for measuring the voltage? A 2-prong contact type AC voltage tester or an AC voltmeter?
1) Pat.......if unable to visually trace out the circuit path, stay on the exterior and measure again for voltage on both of the 50 amp hot's to ground. Have somebody inside the basement turning the respective double pole breakers to the OFF position in order to determine which breaker is feeding the 2 hot's on the exterior that you wish to disconnect.
2) If the conductors were installed in conduit or Greenfield or Liquidtite, you can also gently tug on the wires from the main panel to determine it's destination or any splice boxes along the path to the exterior while a helper listens for the wires moving about inside any conduit or flexible conduit.
3) You can also determine which conductors originate from which breaker by the size of the hot conductors. A 50 amp requires either 6 AWG Stranded Copper or 4 AWG Stranded aluminum. An 80 amp requires either 3 AWG Stranded Copper or 1 AWG Stranded Aluminum. The 80 amp circuit conductors will be a larger wire size.
The wire gauge will also be labeled on the exterior conductor insulation and you can visually determine which conductors belong to the respective double pole breakers.
Hope this helps………If you have any additional questions, let me know and I’ll be glad to answer them for you.
Otherwise, don’t forget to rate me before you log Off.
The next time you have an electrical question, you can also request for me at:http://www.justanswer.com/home-improvement/expert-your-electrician ……….Thanks…………..Kevin!
Its too dark to do all that now so I will take a look tomorrow. Thanks for the clear and thorough suggestions - I never thought of all that. I am using a volt meter and I only measured between the 2 large wires, not to ground.
No problem Pat........take a look at things tomorrow when it is daylight and let me know what you find. Just reply back to me on this question and we can take it from there.
In the meantime, have a great evening and we'll talk at you tomorrow..........Thanks........Kevin.