From NE State Electrical Act:
81-2124 Electrical installations; subject to inspection.
(1) All new electrical installations for commercial or industrial applications, including installations
both inside and outside of the buildings, and for public-use buildings and facilities and any
installation at the request of the owner shall be subject to the inspection and enforcement provisions
of the State Electrical Act. Nothing in here stating minimum dollar amounts before inspection necessary, other sections clarify what is "maintenance" which is not applicable and is basically repair and replacement with similar items. Agriculture operations are exempted at this time, but are not clearly mentioned in the Act.
(2) All new electrical installations for residential applications in excess of single-family residential
applications shall be subject to the inspection and enforcement provisions of the act. Anything in multifamily dwellings basically is no different then what is mentioned above in (1).
(3) All new electrical installations for single-family residential applications requiring new electrical
service equipment shall be subject to the inspection and enforcement provisions of the act. Single family dwellings only require inspection when service equipment is installed. A new home has a new service. A major renovation that does not get new service equipment installed would not be required to have a permit and inspection. All other work that is done when the new service is installed is inspected as well, so a major renovation with new service would need permit, as well as inspection of all new work.
(4) Existing electrical installations observed during inspection which constitute an electrical hazard
shall be subject to the act. Existing installations shall not be deemed to constitute an electrical
hazard if the wiring when originally installed was installed in accordance with the electrical code in
force at the time of installation and has been maintained in that condition. If there is a hazard observed when inspector is at the site, they kind of use some discretion as to how dangerous the problem may be, but they are able to make correction requests for something they see that is existing. If the inspector has to walk by something with exposed live parts to get to some of your installation to inspect - you may as well plan ahead of time to repair/replace that item or inspector will likely tell you you will repair/replace it.
If permit/inspection is not required the State Electrical Act still says in another section:
Except as provided in section 81-2108, 81-2110, or 81-2112, no person shall, for another, plan, lay
out, or supervise the installation of wiring, apparatus, or equipment for electrical light, heat, power,
and other purposes unless he or she is licensed by the board as a Class B electrical contractor, an
electrical contractor, a Class A master electrician, or a Class B master electrician. So you are still supposed to be licensed to do wiring in most instances, some exceptions are homeowners working on their "primary" residence, or some special licenses but you are limited to what that license permits you to do.
NEC is also the code that is adopted as law, so even if a permit or inspection is not required you are still supposed to follow which ever edition of NEC that is in effect, and it now is the 2014. If you don't follow NEC on a job not required to have a permit, nothing is likey to happen. Should someone ever be injured, killed or have property loss because of your non code compliant installation, it certainly will not help you in any related lawsuit.