The invention discloses a
solid insulated totally-enclosed ring main unit, which comprises at least a line of leading-in unit and at least a line of leading-out unit, and each line of switch comprises a 3-phase high-
voltage vacuum switch unit. The high-
voltage vacuum switch consists of a housing fixed inside a box body, and a main switch and an
isolator arranged in the housing, wherein, the housing is made of
epoxy resin, and a
copper joint pin of the main switch and the outside of a
busbar connected with the
copper joint pin are coated with
silicon rubber
layers. The ring main unit of the invention adopts a totally enclosed design, which causes the ring main unit to have a smaller volume and compact structure, and to be safe and reliable; the probability of leakage and
discharge is low, thus improving the insulation class, and the ring main unit has obvious effect on saving energy and materials; air,
moisture, dust and hot and cool air sources are isolated, which effectively retards the
corrosion of a power source body, stabilizes the output of source
voltage, decreases the times of the device maintenance, reduces expense cost and prolongs the service life of the ring main unit.