General introduction

• BGS-40.5 is a air-insulated, metal enclosed switchgear, mainly used in power distribution systems such as power plants, small and medium generators, substations, high-rise buildings, industrial and mining enterprises, subways and electrified railways, to implement the control, protection and detection of power supply systems and loads. It is especially suitable for underground, high altitude, frozen soil, coastal, humid and other environments, densely populated areas and places with expensive construction area.
• The key technologies of product development and design, such as insulation, temperature rise, mechanical strength, sealing, arcing, etc., are all calculated by computer simulation to ensure the quality and reliability of product development.
• In order to ensure the stability and reliability of product manufacturing quality, the company has introduced imported three-dimensional five-axis robot welding equipment, helium quality general leak detector, lightning impact, X-ray detection, partial discharge tester, temperature rise, high and low temperature testing and other equipment.
• Brunstock’s manufacturing partner strictly organises production according to ISO 9000 documents and 6S management to ensure that the quality of the entire cabinet is monitored throughout the process.
• The high-voltage primary components of the product are enclosed in aluminum alloy chamber, maintenance-free.
• The product adopts dry air insulation and vacuum arc extinguishing breaking technology, and the service life of the vacuum circuit breaker is up to 10,000 times.
• BGS-40.5 is designed with an independent arcing channel, and the internal arc classification of the switchgear: IAC-A FLR 31.5kA/1s.

Features

• Dry air insulation, vacuum interruption, environmentally friendly
• No need to fi ll in dry air when on-site installation
• Rated pressure for air fi lled is lower to 0.32MPA
• With unique natural air cooling duct
• Modular design, removeable gas tank and compartment
• The main circuit is fully enclosed and insulated with IP67
• The circuit-breaker is up to 1250A, main busbar up to 1250A and the rated breaking current 31.5kA
• Main bus VT and arrester with isolation switch, easy for operation and maintenance
• Compact size

Advantages

Diversified solution

• This SF6-free switchgear is an integral part of dry air
• Bus and line VT
• Disconnector
• Bus riser
• Metering

Capability of development

• We self-developed the core components (CB and TPS)

Compact size

• Height: 2200mm (the height with LV box, which has a standard height of 500mm, with other dimensions available upon request)
• Width: 600mm/800mm
• Depth: 1300mm

Positioning

Technology

• 40.5kV dry air-insulated switchgear series

Market

• Utility, railway, renewable, oil & gas, mining, etc.
• Africa, Asia Pacific, Middle East, Europe

Quality and cost

• IEC compliant and cost effective

Range of functions

Switchgear cubicle description

Vacuum circuit breaker

Vacuum breaking technology is adopted for the circuit-breaker on BGS-40.5, including features:

• Maximum rated current :1250A
• Rated short-time withstand current: 31.5kA/4s
• Rated short-circuit breaking current: 31.5kA
• Electrical endurance: E2
• Mechanical endurance: M2 (10,000 times)

Function

• Open and close
• Short-circuit breaking and making operations
• Corporate with three-position switch to achieve earthing function

The three-phase pole of the circuit breaker is horizontally placed in the circuit breaker air tank, the operating mechanism is located outside for easy maintenance. The mechanism and the pole are connected by movable sealing bellows.

Bus connector

Top extension busbar is used between the cabinet of BGS-40.5 with the maximm rated current of 1250A. The installation is convenient, and it has low requirement on foundation fl atness.The partial discharge of each solid bus can be achieved within the range of 5pC at 45kV voltage.

Example of busbar connection

There are two main types of busbar connection:

• Three-way busbar connector is applied to the end of switchboard and bus section panel
• Four-way busbar connector is applied to the middle switchgear

Operating mechanism (three-position switch and circuit breaker)

The operation buttons and position indication of the circuit breaker, three-position switch and air pressure manometer involved in BGS-40.5 are all embodied on the front cover panel. The operation and indications are user friendly. The specific structure is shown below:

Current instrument transformer

BGS-40.5 has ring-type CTs, which can fit incoming/outgoing single or multiple cables and the main busbar. The primary current of current transformer ranges from 100A to 1250A, and the secondary current is rated as 1A or 5A. The specific core quantity, accuracy and capacity of the CT shall be determined when ordering.

CT installation in the cable compartment

The ring-type CT can fit the incoming/outgoing cable and is fixed on the beam on the cable compartment, as shown as below.

CT installation on main busbar

The current transformer on main bus of BGS-40.5 can fi t the main bus and is fixed on the top of the cubicle

Voltage transformer

The voltage transformer (VT) in BGS-40.5 is designed with an insulated medium voltage terminal with a plug-in connector, and the VT is directly plugged into the special socket on the bottom side of the air tank. The VT core and the winding are integrated, and can be protected by a fuse (optional). The fuse is installed inside the VT and its current matches the short-circuit current withstand capacity. This effectively protects the VT when the power grid has problems, such as harmonics. Please see the figure below for VT with or without a fuse.

The VT secondary voltage is 100V, and the secondary core provides measurement and protection function. For example: 35/√3/0.1/√3/0.1√3/0.1/3kV. VT specific secondary core quantity, accuracy, capacity and other characteristics are determined when
ordering.

VT without fuse

LV box

Brunstock’s LV box is modular and has a withdrawable design. The standard height is 500mm, which can be customised. The low-voltage components and accessories are designed according to customer requirements.

BGS-40.5 is equipped with cable bushings which comply with EN 50181 and IEC 60137 for termination of cables. The bushings fulfil the
requirements of DIN47636T1. The following cable bushings are used:
Interface C with M16 x 2 metric threads 400 series, In = 630 A
Standard on all modules and for side connection

Interface B with plug 400 series, In = 400 A
Optional for all modules.
The yellow area indicates the silver coated contact spring.

The installation instruction from the manufacturer of cable terminations must be followed. Be sure to lubricate the bushings thoroughly with silicone supplied

Important:

Where cables are not connected, the earthing switch must be locked in closed position or the bushings must be fitted with dead end receptacles before the unit is energised.

Cable terminations

All bushings are protected by cable compartment cover. The drawings below show typical arrangements with cable connectors.
The table below the drawings shows the distance A in millimetre from cable bushing to the inner part of cable compartment cover.

Surge arrester

BGS-40.5 surge arresters use plug-in connection with the cubicle and can be categorised by two types cable bushings:

• Outer-cone bushing

Surge arresters should be located in the cable compartment. The specific technical parameters of arresters are determined when ordering.

The outer-cone comes with a rated voltage of 41, 42, 51, 52.7 or 54kV.

Interlock

Electrical interlock

• Electrical interlock can be achieved by intelligent control and protection unit’s contact detection and logic programming for position state of TPS and CB, and it can be achieved by microswitch as well
• The electrical interlock can be worked only when secondary power supply is powered
• Electromagetic lock is optional for ES

Mechanical interlock

• Mechanical interlock can only be achieved by operating the main shaft with TPS manually under certain conditions
• When circuit-breaker is closing, the manual operation cover of DS is interlocked. Only after the CB is opened, the cover can be freely opened, then the handle can be inserted into the hole for DS operation. whenever opened the cover manually, the CB cannot be operated electrically or mechanically
• Key lock and padlock is optional for CB/DS/ES upon request

Interlocking of the functional units

During the development of BGS-40.5, emphasis was placed on personnel safety and the reliability of the switchgear in operation. An interlocking system prevents any incorrect use. Thus, the operating levers can only be inserted if the service status permits it. Access to the cables compartment is only possible if the appropriate outgoing feeder is connected to earth.

These ring main units are equipped with the following interlocks:

Functional unit with vacuum circuit breaker, disconnector and earthing switch

Interlock status (IS)

This web page is a HTML version of the catalogue PDF (part 2 of 2). See part 1. You can download the PDFs about this product from the main SF6-free RMUs page.

Step-up stations

• Step-up skid stations for BESS
• Step-up substations for solar farms

Green GIS

• Primary switchgear
• Secondary switchgear rated to 12kV