This SF6 ring main unit is a new generation of metal enclosed switchgear with SF6 load switch as the main switch. The whole switchgear is air insulated, using sensor technology and latest relay protection components with a leading international design level. The best indoor ac unit is applied with vacuum circuit breaker as the main switch. Withsimple and compact structure, flexible and convenient operation, reliable and effective interlock, this kind of switchgear is mainly used for ring network power supply ordual radiation power supply system with three phases rated frequency of 50-60Hz and rated voltage of 12kV, as the circuit control and protection device. This indoor unit for ac is especially suitable for power systems such as small secondary power distribution station, cabinet transformer substation, switching station, industrial and mining enterprises, city Communities, airports, hospitals, railways, tunnels, high-rise buildings. It could be used for andproviding safety, reliable automatic services forpower supply station. Different places, different users, different technical schemes.
Main structure for looped network cabinet
RMU consists of busbar room, three position load switch room (or circuit breaker room), cable room, operation mechanism, interlock mechanism and low-voltage control room and measurement. Each cabinet is separated by steel plate to avoid accident spreading. The product complies with AC metal enclosed switchgear and control equipment referred to GB3906 3.6KV-40.5KV, and rated voltage 1KV- 52KV AC metal enclosed switchgear and control equipment referred to IEC62271-200.
1. Busbar room: Busbar room is in the top of the switchgear in which the main busbars are connected together and through the whole switchgear. Main busbars are horizontally arranged which are easily to be extended.
2. Load switch room: There is a three-position load switch installed in this room. Its shell is made of epoxy resin with SF6 gas filled in as the arc extinction and insulation medium. There are two transparent hot- stamped plastic end caps on the operating shaft terminals. The contact status can be observed through the end caps. SF6 gas density meter or density meter with alarm can be installed as per customer requirement.
3. Cable room: The cable room is used to connecting cables. Single core or three-core cable can employ the simplest shielded cable head for connecting. Meanwhile, it can be equipped with arrester, current transformer, voltage transformer and lower earthing switch. In terms of standard designation, there is an observation window and safety interlock device. The bottom plate of the cable room is equipped with sealing cover and suitable cable clamps with mountings. The door on the bottom plate of the cable room is removable, which is easily for cable installation and remove.
4. Operation mechanism, interlock mechanism and low voltage control room: Low voltage control room with interlock also plays a role as a control panel. In the low voltage room, there are spring operation mechanism and interlock mechanism with location indicator, auxiliary contact, tripping coil, emergency tripping mechanism, and condenser charging indicator, key lock and manual operating device. In addition, control circuit, meter instruments and protective relay can be fixed in the room.