Electrical Industrial Medium Voltage Switchgear Low Voltage Intelligent Control

● Four compartments compose the switchgear

The switchgear is composed by four compartments, they are ① busbar compartment, ② switch compartment, ③ cable compartment, ④ operating mechanism, interlocking mechanism and low voltage control compartment.

---- Busbar compartment

The busbar compartment is at the top of the switchgear. The main busbars are connected together inside of the busbar compartment and throughout all switchgears.

---- Switch compartment

There is a three-position load switch inside of the switch compartment and the enclosure of the load switch is made of epoxy resin, what is more, SF6 gas is full of it as the insulated medium and the outside of the enclosure has a watch window. As the request by the customer, it can install a monitor with alarm contact to inspect the SF6 gas pressure.

---- Cable compartment

Its cable compartment has enough space. It is mainly used for cable connection which makes the single core cable or triple core cable connected by the most simple unshielded cable head. On the other hand, this enough space can also contain the other parts, such as surge arrester, current transformer, earthing switch at lower end etc. As the standard configuration, the enclosure door is equipped with watch window and interlocking device. The cable base plate has the sealing cover and cable fixation clamp with support bracket. What is more, the cable base plate and the enclosure door front frame can be removed, so it is very convenient to install the cable.

---- Operating mechanism, interlocking mechanism and low voltage control compartment

The low voltage compartment with the interlocking device can also be the control panel. Inside of the low voltage compartment can not only have the spring operating mechanism with position indicating device and mechanical interlocking device, but also can be equipped with auxiliary contact, tripping coil, emergency tripping mechanism, capacitive voltage indicator, key lock and electric operating device. Meanwhile, the low voltage compartment can also be equipped with control circuit, meters and protection relay. The unit of 750mm width has two same low voltage compartments which can be equipped with more accessories. The whole unit of CXGN/FL switchgear including two parts, upper part of the unit and lower part of the unit. The upper part of the unit including busbar compartment, load switch, low voltage compartment with operating mechanism. The lower part of the unit is cable compartment. These two parts can be separated. So, it can be very conveniently and safely to check or reform the upper part, also can replace it.

● Using SF6 gas for insulation

---- The inside of the switch enclosure is full of SF6 gas.

---- The feature of SF6: non-toxic, colorless & odorless, nonflammable, inert, heavier-than-air and with electronegativity (high quality insulating material).

---- SF6 gas pressure inside of switch enclosure:

Inflation pressure (gauge pressure) : 0.042～0.045Mpa

Maximum pressure: 0.048Mpa

Design temperature: 80℃

Action pressure of structure vulnerable point: ≥0.08Mpa

---- Annual leakage rate of SF6 gas ≤ 0.1% per year

● Load switch and earthing switch through interlocking device and stored-energy spring to comprise the operating mechanism

---- Thanks to the bluing, all parts of the operating mechanism have rust-proof performance.

---- The operating positions for load switch and earthing switch are not only independently but also closely related.

---- The operating process is simple and easy, and the operating result can be easily indicated.

---- It can operate by manual or electric.

● Logic mechanical interlocking to prevent faulty operation

---- Earthing switch can’t be opening or closing unless closing the enclosure door.

---- Enclosure door can’t open or close unless closing the earthing switch.

---- Load switch can’t be closing or opening unless opening the earthing switch.

---- Earthing switch can’t be closing or opening unless the load switch is opening.

● Safety

---- All high voltage parts which including cable terminal connector and busbar are installed inside of enclosure.

---- Capacitive voltage indicator can check whether it is isolated from the power safely.

---- The operating mechanism and auxiliary switch are isolated from the primary side.

---- The logic mechanical interlocking can prevent faulty operation

---- The sealed gas tank has one structure vulnerable point which can release the over pressure, which makes it can ensure the safety of operator.

● Stable and reliable working

---- No maintenance in the indoor environment.

---- The operating mechanism is isolated from the primary side.

---- Current transformer is installed at outside of gas compartment.

----  Annual leakage rate of SF6 sealed chamber is less than 0.1% year.

---- It passed type test and factory inspection before delivery.

---- It is produced in the standard production process and its quality control meets ISO9001.

● CKFL-S type load switch

CXGN/FL is the new generation of CKFL-S type SF6 load switch.

----Design & Structure

CKFL-S is the load switch with the design of double open contacts, three positions and rotary moving contact. Its enclosure is made of high-strength epoxy resin and it uses SF6 gas as arc-extinguishing medium. The inside of each switch is fully sealed with 0.045Mpa gas pressure and passed Helium leak test, so no leakage happens. The switch can be in horizontal installation or in vertical installation. The typical installing type inside switchgear is installing a steel plate between the cable compartment and busbar compartment, and then to be in horizontal installation. If arcing occurs in the switch, the special structure which is at the back side of the enclosure will be broke and then release the high pressure gas.

----Operating mechanism

The spring operating mechanism can make load switch close or open. The mechanism spring needs to store energy in advance, and then in the process of manual operation or electric operation, the spring will release the energy after the mechanism pass the top point, then the switch motion will be driven and make the contact close or open. So, the closing/opening speed of the switch is decided by the operating mechanism not by the operating speed of the operator.

★Type K operating mechanism

This operating mechanism is used for opening/closing and earthing. The operating energy comes from spring mechanism. The part matches with mechanism is equipped with position indicating device and mechanical interlocking device, so it can ensure the operating procedure is correct.

★Type A operating mechanism

This operating mechanism adds extended function. Excepting for the functions of closing/opening by manual and earthing, it has another function of fast release breaking. It can use for fusing releasing, voltage releasing, current releasing or fast tripping by manual button, etc., so it can provide fuse protection, voltage protection, overcurrent protection or temperature protection for transformer.

---- Optional parts

Electric operation: AC220V/110V DC220V/110V

Auxiliary contact: 2pcs always opening 2pcs always closing

Shunt tripping coil (only for type A mechanism): AC220V/110V DC220V/110V

Auxiliary switch for fuse fusing

FTU communicating interface

Fault indicator

Gas-pressure meter