Versions of (r)

electric generators and electric alternators that are portable or mobile, including drive motors therefor, and generator and alternator sets that are portable or mobile, except when such generators, alternators or sets are purchased for use on a farm for farm purposes only; stand-by electric generators and stand-by electric alternators, including drive motors therefor, and stand-by generator and stand-by alternator sets, for the production of electricity for use primarily in a building that normally utilizes electricity supplied by a public or private utility where that building is used primarily for activities other than the manufacture or production of goods,