I am upgrading my service and am wondering if the panel box needs to be installed on an exterior wall? I plan on leaving the existing service in place while running all new wire to the new panel box. The existing panel box is in a corner on the exterior wall, can I put the new box on the interior wall opposite the old box?

Okay, we really need to level set what you are talking about and to make sure you know how to do this work. You could quite easily get yourself killed, dead!

You are going to have to get a permit for this type of work and the State may require that only a licensed electrician do the work. Here in Virginia, you must be a licensed electrician or the home owner to get a permit. If you are not licensed and the level of the work is dangerous you have to prove that you are capable of doing the job.

You need to start this conversation with your power company to make sure they have the equipment in place to handle the upgrade. If not, then they may have to do the necessary line work.

You do you understand that you will be working in a definite KILL zone. That the meter base will need to be changed out and the wires from the meter base into your home will have to be changed to the appropriate size. Now what this means is that you will be working on in an area in very proximity to unprotected live wires (unless you have the power company kill the leads from their transformer to your home). The meter has to get pulled.

You cannot just move the main panel. There are NEC, fire and building codes regarding the placement of the panel and the feeder cables, not to mention the grounding and bonding systems.

Next your process has to be planned out prior to getting the permit issued. One big issue would be what you are going to do with the existing panel board. Your post indicates that you want to leave it where it is and put the new panel on an inside wall. Is the old panelboard going to become a subpanel off the new main service panel?

NEC says you will put the main panel or main disconnect switch as close to the entry point of the service cables. You post has you running the service cable through the building, which you cannot do under current rules. There only two ways to get the panel on an inside wall. (1) Place the service cable under two inches of concrete under your building. (2) Install a main service disconnect at the point of entry and then the new panel would become a sub panel off the main disconnect switch.

And just so you know, once you get the meter installed back on the meter base and power restored to the meter, you will still have a kill zone to work in while you are installing the new panelboard and all the branch circuits into the new panelboard.

CJ,

Let's see here, "Up State, New York" is a rather large area. Shall we guess at the "Local Authority Having Jurisdiction" is, because they are the enforcing agency.

I did answer the question. The title of your question wants NY Code, which would be an overlay of the NEC.

The body of your question is severely flawed with code violations. Sorry I tried to help. It will not happen again.