8BK18

8BK18 HIGH-VOLTAGE SWITCHGEAR

TECHNICAL SPECIFICATION

1、 PROUCT GENERAL DESCRIPTION

KYN□ (8BK18)-12(Z) metal-clad removable type AC switchgear device is the 8BK18 type switchgear which is   authorized by Siemens to produce and sell, which is advanced product with international standard through continuous improvement and design, is able to fully meet the demand of substation, power plant, and is a good companion for a safe power distribution.

KYN□(8BK18)-12(Z) metal-clad removable type AC switchgear device meets the standards of IEC, GB, DL, DIN VDE and pass the comprehensively type test of internal high-voltage test center. It supports a reasonable design, reliable performance, contemporary with the advanced international level, to better meet the requirement in high reliability for user, and have related product certificate.

2、APPLICATION SCOPE

KYN□ (8BK18)-12(Z) metal-clad removable type AC switchgear device is widely used in the various fields, such as power plants, high-voltage/middle substation and high capacity middle substation, substation system, industrial and mining enterprises, civil building infrastructures etc.

3、STANDARDS

KYN□(8BK18)-12(Z) metal-clad removable type AC switchgear device meet the following international and internal standards:

4、MAIN TECHNICAL DATA:

4.1 CONDITION FOR NOMAL USE

4.2、Electrical Data

4.3、Overall Dimension

5、Structure

5.1 Using 2~3mm aluminium and zinc coated and imported hot galvanized steel plate with strong corrosion. Resistance, as well as the double bending process, enable the strength of the case body to be greatly improved.

5.2 The switchgear consist of two major portions: fixed case body and withdrawable carries. The partitions, used for the enclosure and functional units, are made from hot galvanized or aluminium coated steel sheets, which are processed with numerical controlled machine tool, then be bent and bolted to take shape,. Inside the switchgear, there are circuit breaker compartment, busbar compartment, cable-compartment and low voltage compartment. For the distribution of different functional elements and assembly of principal electrical components.

5.3 Respectively, there is a relieving device over the circuit breaker compartment, busbar compartment and cable compartment. When the failure, followed with electric arc occurs in a certain compartments, causing the rise of pressure, the relieving device will be actuated and the relieving plate opens automatically, and the pressure and gas are relieved, thus ensuring the personal safety of the operators. On the top of the high pressure room of the switchgear, exhaust device are provided. When pressure inside the cabinet is boosted because of malfunction electric arc, the pressure exhaust device on the top will be automatically opened. Since the door of the switchgear have been enclosed by the special hermetical enclosure on the door of switchgear, the high pressure air is exhausted out side of the cabinet quickly through its individual exhausting passage and it can reach higher protection grade, allowing the equipment and operator be reliably protected. The adjacent cabinets are separated by each side plates. When the cabinet components assembly together, 5mm air buffer layer will be made between the side plates, it can be avoid the cabinet are run through by the malfunction electric arc, reduce the affects caused by the electric arc malfunction. The low-voltage room is the separated room which is separated with 3 high-voltage room.

5.4 “Five-prevention” interlocks functions and locking device are available.

KYN□(8BK18)-12(Z) metal-clad removable type AC switchgear device use the  “Five-prevention” interlocks functions and locking technology which are authorized by Siemens, with complete, safe and reliable mechanical “ Five-prevention” locking device which can be able to prevent the erroneous operation.

Five protection functions

(1) Protection from switching on or switching off isolating switch, with load.

(2) Protect from mis-switching on or switching off isolating switch,

(3) Protect from switching on gate with earthing cable,

(4) Protect from hanging on “earthing cable” when there is electricity.

(5) Protect from mis-entering into electricity partition

A safe and reliable interlocking device, which can fully meet the “five-prevention” requirements, is fitted in the switchgear: There is a KK-type changerover switch on the door of the instruments cubicle, to prevent erroneous switching on or switching off of the circuit breaker. The circuit breaker can be switched on or switched off when its carries is in “Testing” or “Working” position, and the carrier is not possible to move when the circuit breaker is switched on, preventing the erroneous operation of the circuit breaker on load. Only when the earthing switch is in the “Off” position, the circuit breaker carrier is in “Off/testing” position to “Working” position; and only when the circuit breaker carrier is in “Off/testing” position, the earthing switch can be switched on. So it may prevent erroneous switching of the earthing switch on load and the switching of the circuit breaker when the earthing switch is in closing position. When the earthing switch is in “Off” position, the back door can not be opened, thus preventing the entry into energized interval (there is a partition between front and rear cable compartment.) When the carrier of the circuit breaker is in “Working” position, the secondary connecting plug is locked and can not be pulled out. Each case body can be equipped with an electrical interlock. An electro-magnet locking device can be added to the operating mechanism of the earthing switch for this switchgear to improve the reliability. The electromagnet device can be ordered according to customer’s choice.

5.5 The base of the carrier is made from cold rolling steel plate treated with riveting and welding. According to the different purposes, there are carriers for circuit breaker, voltage transformer, metering and isolation and so on. Owing to the use of unique design, the base of the carrier is driven by precision screw rod, so it can be drawn out and pushed in easily. The carrier of the same type have an excellent interchangeability. The carrier inside the switchgear has its positioning mechanism for testing or working position. Even when the door of the switchgear is closed.

5.6 The circuit breaker compartment has equipped with a particular slideway for the move and positioning of the carrier. When the carrier is drawn out or in the testing position, the primary energized portion inside the case body is separated by the movable insulated partition, ensuring the operator from touching the energized conductor, When the carrier moves from the Testing position towards the Working position, the movable partition will be gradually actuated until the carrier is fixed at Working Position. When the carrier is at the Testing position, the secondary adaptor is energized, and at this time, the carrier can carry out the tests required. The working position and the operating conditions of the equipment can be surveilled through the peep hole on the door of the carrier compartment.

5.7 The switchgear has a reliable mechanical locking device which ensures the safety of the operators. Only when the carrier is in test/isolation position or working position, the operation of On/Off can be carried out for circuit breaker. Only when the circuit breaker is switched off, the VCB can be removed. Only when the earthing switch is switched off, the carrier can be moved into working position. Only when the carrier is in test/isolation position or after the carrier have been drawn out, the earthing switch can be switched on. When the carrier is in working position, the secondary inserter can be locked and is unable to be pulled out. Only when the earthing switch is switched on the door of the cable compartment can be opened. According to the clients’ request, the electrical interlock rather than the original design can be established.

5.8 The connection of Busbar connection terminal: for main busbar: Maximum rated current is up to 4000A, rated short-time withstand current is up to 50kA, peak value withstand current is up to 125kA.

5.9 Fix a particular nameplate on the front panel of the switchgear, which is produced by using the laser carven and also with high resistance to flammability and corrosion. It meets the GB standard that have the logo of components function and primary simulative wiring diagram, have the advantages such as clear symbol, fastness and serviceable and changeable etc.

5.10 One withdrawable position is set in each cabinet of busbar, main busbar and down-lead are treated by insulation process. Use the thermal plastic insulator to insulate (including busbar and down-lead should use the withdrawable pyrocondensation box), the insulation level should reach above 42kV.

5.11 The insulator inside the cabinet use the SMC type resistance to arc, high temperature, flammability, low poison, anti-damp and also have the material with excellent mechanical strengthen and electrical insulation.

5.12 HV compartment inside the switchgear has the metal steel protection secondary wiring channel, metal steel protection is added in the exterior position in order to prevent the HV arc being burn the secondary wiring and equipment. At the same time, the screening function is worked so that can be able to prevent the interference caused by the HV electric field to the secondary Computer protection device.

5.13 When the carrier of the circuit breaker is in “Working” position, the secondary connecting plug is locked and can not be pulled out. Only when the earthing switch is in the “Off” position, the circuit breaker carrier is in “Off/testing” position to “Working” position; and only when the circuit breaker carrier is in “Off/testing” position, the earthing switch can be switched on. So it may prevent erroneous switching of the earthing switch on load and the switching of the circuit breaker when the earthing switch is in closing position. When the earthing switch is in “Off” position, the back door can not be opened, thus preventing the entry into energized interval (there is a partition between front and rear cable compartment.)

5.14 The switchgear have the monitoring window which is used to monitor the operation switching on and off for the circuit breaker. The particular glass is installed in the monitoring window with resistance to explode and flammability, and with the withstand capability to the internal arc as same as the switchgear.  

5.15 In the cable compartment, where may install with current transformer and earthing switch, used to monitor the voltage transformer and lightning arrester, etc. In addition, a certain number of cables can also be installed. For construction, the constructor may enter the cable compartment from the front or from the rear. The compartment has sufficient operating space if the constructor. The height between the primary cable terminal to the ground is not less than 750mm, and leave three Ф120mm cable connection hole, and also provide the cover plate for the cable entry (have particular sealed cover), one support is added in the bottom of the cable compartment in order to support and fix the CT, and set a fixed hole on the support.

5.16 The earthing busbar of the switchgear is installed at the base of the case body. The earthing of the carrier is fulfilled by the connection of earthing contact with earthing busbar. Use copper bar as earthing busbar. The earthing busbars of neighboring case bodies are connected reliably by special purpose connecting plates. (DC resistance of the copper bar is 0.01773Ω per meter; conductance rate of the copper material is 98%; copper contents is 99.98%). Main busbar and down-lead use the pyrocondensation insulator with good performance, dampproof, resistance to flammability and good performance in draws off heat, which thickness is not less than 2mm. The pyrocondensation insulator can be withdrawable in one connection point of the copper bar.

5.17 The connect length in the connection of busbar is not less than 100mm, the hole is formed by the standard tooling with only one time. And add the pressed flower in order to increase the touch area and silver plated treatment, to ensure the flatness of the connection surface meet the standard requirement, so as to reduce the resistance when connected, reduce the temperature for the connection surface. The leveling space between the support insulators is not over than 1200mm, vertical space is not over than 1000mm.

5.18 Lightning arrester and voltage transformer can be installed on the withdrawable carrier.  

5.19 The switchgear can be equipped with the following vacuum breaker with good performance: 3AH-type produced by Siemens, Evolis series produced by Schneider Electric Company, VD4 series produced by ABB, VS1 series produced by Changzhou Shenyuan Switch Co., Ltd.

6. Switchgear with excellent performance such as anti-damp, anti-mildew, anti-salt spray and anti-corrosive.

6.1 Metallic parts are adopted of the technology procedure of pre-process medicament which the same treatment on automobile surface, degrease, zinc plate (3mm thickness), Chromium deactivation, and greatly accelerate the combining capacity, antirust capacity, impulse withstand of powder coating.

6.2 All the fastener needs for protection treatment according to the requirement of GB JB/Z88 《Electroplate of humid tropics electrical product》, with superior performance of  “anti-humid & heat” “anti-salt spray” “anti-mildew ”.

6.3 The technology of surface spray coating is most advanced in static power auto spray coating production line of Switzerland Primer Company, which use the high-quality power in Epoxy resin polyester mixed type, the average thickness of coating arrive at 50-80μm (GB is over 60μm), pencil hardness reaches 2H (GB is HB), anti-salt spray test achieves 10 cycles and above (GB is for 4 cycles), with advantages of strong coating adhere, high hardness degree, anti-aging, good fasten of light & color, anti-damp, anti- mildew, anti-salt spray, anticorrosive.

7、Safe and Easily Operation Maintenance

7.1 The switchgear has complete, safe and reliable mechanical “ Five-prevention” locking device and has the perfect & credible mechanical closedown fitting to avoid error. The three position of ON, BREAK and TEST are on the frame breaker unit in fixed isolation switchgear. Under TEST position, automatically locate and lock up. The position of ON, CUT, TEST, ISOLATION and draw-out is on the drawer unit of draw-out switchgear. When the drawer is pushed on the position of ON, CUT, TEST and ISOLATION position.

7.2 The interchangeability of the same type vacuum breaker is high, the carrier of breaker and maintenance carrier are the separated structure, the carrier of breaker and maintenance carrier can be made to be the integrative structure(apply to the operation mode of power plants), it can be maintained and repaired in easily.

7.3 Mechanical Locking device can be able to inspect the power firstly, and then implement the earthing procedure, which ensures the safety during operation and maintenance.

7.4 The cable compartment has sufficient operating space for constructor. Installation height of the cable is high (The height between the primary cable terminal to the ground is not less than 750mm), can be connected with many cable. The fixed position of the cable terminal can be adjusted, it can be operated, maintained and install the CT in easily; cable entry hole use the particular sealed plastic cover in order to effectively avoid the small animal into the switchgear.

7.5 The switchgear have the complete and reliable earthing system and visible earthing symbol, the metal frame of each cabinet and all high-voltage components inside are connected reliably by special earthing copper bar The earthing busbars of neighbouring case bodies are connected reliably by special purpose connecting plates which ensures the safety of the operators.

7.6 Secondary elements such as measuring instruments relay protection device, terminals and control switches etc are individually installed inside Low Voltage Compartment which is closed by earthing metal steel. Closed cable groove and layout are used in secondary return circuit, and also is separated from the high-voltage compartment, can be able to prevent the electromagnetism interference caused by high-voltage electrification and foreign equipments, in order to improve the safety and reliability of the operation.

7.7 The monitoring window/ power inspection window hole with high strength resistance to exploding, flammability, and made from natural metal materials and fixed up by the special bolt on the rear lower door of the switchgear. The power inspection stick can be operated after opened the window by using the special tool during the rear door is closed.  

8. Main Elements for Return Circuit

（Select and use 3AH mid-position carrier circuit breaker produced by Siemens, or equipped with the other brand of circuit breaker )

1) 3AH vacuum circuit breaker

4 Outstanding vacuum circuit breaker fully meet the standard of China.

4 Compactive design of circuit breaker is hardly suitable for all types of cabinet in China.

4 Compare with the domestic breaker, have longer service life. Advantage in the price within the unit time.

4 Fully free maintenance within the whole service life of the circuit breaker (10000 times)

4 All products are inspected by advanced and high automotive test equipments.

4 Invariableness insulation strength

Closeness vacuum arc extinguishing compartment eliminate the affects to the environment.

No air decompose matters in the vacuum.

4 Invariableness Connecting Resistance

The contact is not oxidated in the vacuum.

Tiny contact resistance will not be changed in the service life.

4 High Switching Frequency

Damage caused to the contact is less, so the switching frequency of rated current is up to 30000 times, the switching frequency of rated short-circuit current is up to 100 times.

4 Economic Advantage

Free of Maintenance for Vacuum arc extinguishing compartment

Free of Maintenance for Vacuum Circuit Breaker of Siemens

Within the whole service life, can reach 10,000 times switching on and off operation circle or most frequently operation in the normal condition, and no failure operation in long period of time.

4 Use the special vacuum bubble and contact materials

Interior Pressure 10-6 mb

Contact Space 6-20 mm

Contact Resistance approx 10

CuCr50/50 is considered as the perfect contact materials.

2) Earthing Switch

MGES earthing switch is produced by Schneider Electric which is specially used in HV switchgear. It is designed on the basis of the switchgear and a fas-acting closing mechanism independent of the operating speed of the operator, this switch designed for a high making capacity.  MGES earthing switch has been tested in accordance to the type test which are conducted in Xian High Voltage Electrical Equipment Research Center and have passed all the test. In addition, this switch have been awarded the Type Certificate and Use Certificate for JN23 Outdoor AC Earthing Switch.

3) Voltage Transformer(PT)

Select and use the dry type rosin casting voltage transformer produced by Dalian Beifang Transformer Factory, Zhongshan Guzhen Transformer Factory or Sihui Transformer Factory, meet the international and national standard.

4) Current Transformer(CT)

Select and use the dry type rosin casting current transformer produced by Dalian Beifang Transformer Factory, Zhongshan Guzhen Transformer Factory or Sihui Transformer Factory, meet the international and national standard.

5) Lightning Arrester

Select and use the lightning arrester produced by Guangzhou Huasheng Lightning Arrester Factory, mode is HY5WZ1-17/50.