What is the difference between ring main unit and switch cabinet?

The switchgear is divided into ring main unit, center cabinet, GG1A, etc. There are also many types of ring main unit.

The so-called “ring network cabinet” means that each power distribution branch is equipped with a switch cabinet (outgoing switch cabinet), and the bus bar of this switch cabinet is also a part of the ring trunk line. The ring trunk line is composed of the bus bars of each outlet cabinet. Each outlet cabinet is called a “ring main unit”. In fact, if you take out a ring network cabinet alone, you can’t see the meaning of “ring network”. These ring network cabinets are not large, so the high-voltage switch of the ring network cabinet generally does not use a circuit breaker with a complicated structure, but a simple-structure high-voltage load switch with a high-voltage fuse.

The high-voltage switch in the ring main unit is generally a load switch.

The ring main unit uses a load switch to operate the normal current and a fuse to cut off the short-circuit current. The combination of the two replaces the circuit breaker.

Of course, this can only be limited to a certain capacity. Such switchgear can also be used in the distribution system of non-ring network structure, so with the wide application of this switchgear, “ring main unit” has jumped out of the category of ring network power distribution and generally refers to load switch The high-voltage switchgear is now the main switch.

The ring network refers to the ring main unit , that is, the power supply main line forms a closed loop, and the power supply supplies power to this ring main line, and then distributes power from the main line all the way through the high-voltage switch. Each power distribution branch can take power from its left main line, and it can take power from its right main line. When the left main line fails, it continues to receive power from the right main line, and when the right main line fails, it continues to receive power from the left main line. In this way, even though the main power supply is single-circuit power supply, However, from each distribution branch, the benefits similar to dual power supply are obtained, thereby improving the reliability of power supply.


Post time: Nov-09-2021