What are the differences between switchgear and SF6 ring main unit?

A SF6 ring main unit is a totally sealed, gas-insulated compact switchgear unit. The primary can be either switch disconnectors or fused switch disconnectors or circuit breakers. Intelligent complete sets of electrical switch equipment and intelligent controller products are an important part of the manufacturing of intelligent SF6 ring main unit.

How many parts does SF6 ring main unit consist of?

What are the differences between switchgear and SF6 ring main unit?

What are the differences between branch box and ring main unit?

How many parts does SF6 ring main unit consist of?

Isolators with earthing switches, also called load break switches are connected by incoming cables in the SF6 ring main unit. Each with integral load breaking earth switches, having three positions ON, OFF and EARTH.

SF6 ring main unit has a circuit breaker with earthing switches. Outgoing cable is connected to the transformer through circuit breaker.

SF6 ring main unit has capacitor voltage dividers serving live-line cable indicators, which are used for verification of safe isolation from supply.

SF6 ring main unit has fault passage indicator, which is used to detect faulty cables. It can sense short circuit and earth fault currents separately.

SF6 ring main unit has numerical relays for O/C and E/F protection

A power supply unit, including auxiliary power transformer and battery backup, is used to provide stable 24V DC sources of power.

Current transformers, potential transformers and HRC fuses are also equipped.

What are the differences between switchgear and SF6 ring main unit?

The SF6 ring main unit is a group of transmission and distribution electrical equipment installed in a metal or non-metal insulated cabinet or made into an assembling interval type ring network power supply unit. The core part of SF6 ring main unit adopts load switch and fuse, which has the advantages of simple structure, small size, and low price. SF6 ring main unit can improve power supply parameters and performance, and power supply safety. It is widely used in load center distribution stations and box-type substations in urban residential districts, high-rise buildings, large public buildings, factories and enterprises.

The switchgear is a kind of electrical equipment. The outer line of the switchgear enters the main control switch first, and then enters the sub-control switch. Each branch is set according to its needs, such as meters and motor magnetic switches.

The switchgear is divided into high voltage and low voltage, while the SF6 ring main unit belongs to the high voltage switchgear. The ring trunk line is composed of the busbars of each outlet cabinet connected together, and each outlet cabinet is called a SF6 ring main unit. The high-voltage switch is a load switch to operate with a normal current, and the fuse cuts off the short-circuit current.

What are the differences between branch box and ring main unit?

The main function of the cable branch box is to branch or transfer the cable, which is widely used outdoors. With the advancement of technology, the number of cable branch boxes with switches is also increasing. Urban cables often use double-loop power supply so that some people directly call the branch boxes with switches as outdoor ring main unit, but most of them cannot realize distribution network automation.

The main purpose of the ring main unit is to realize dual-loop or multi-loop power supply to increase the possibility of power supply. At present, the advanced ring main unit can realize the automation of distribution network and realize long-distance operation.

Learn more about SF6 ring main unit can know the differences between switchgear and SF6 ring main unit and branch box. You can know more about us, Rockwill T&D Group on our website.