China 36kv Air-Insulated Metal-Clad Withdrawable Switchgear

1. Summary

1.1 General

(Figure 1/1)

KYN61-36 air-insulated metal-clad withdrawable switchgear (hereinafter as switchgear is a kind of MV switchgea r.

It is designed as a withdrawable module type panel, and the withdrawable part is fitted with VD4-36E,VD4-36

withdrawable vacuum circuit breaker manufactured by FARADY Electric Company . It can also be fitted with isola

tion truck, PT truck, fuses truck and so on. It is applicable to three phase AC 50/60 Hz power system,and mainly

used for the transmission and distribution of electrical pow er and control,protection,monitoring of the circuit.
1.2 Description of Product Model Number

1.3 Standards and Specifications

IEC60694 The commo n technical requirements of high voltage switchgear and controlgear

IEC62271-200 A.C. metal enclosed switchgear and controlgear at the rated voltage of 1kV~52k V

IEC62271-100 High voltage switchgear and controlgear-Part 100:High voltage A.C. circuit breaker

GB3906 3.6~ 40.5kV alternating current metal enclosed switchgea r and controlgear

GB1984 High voltage alternating current circuit breaker

GB/T11022 The commo n technical requirements of high voltage switchgear and controlgear

DL/T404 3.6~ 40.5kV alternating current metal enclosed switchgea r and controlgear

1.4 Service Conditions

1.4.1 Normal Operating Conditions

A. Ambient temperature: -15 40

B. Ambient humidity:

Daily average RH no more than 95%;Monthly average RH no more than 90%

Daily average value of the steam pressure no more than 2.2k Pa, and montly no more than 1.8kPa

C. Altitude no higher than 1000m;

D. The air around without any pollution of duty,smoke,ercode or flammable air,steam or salty fog;

E. External vibration from switchgear and controlgear or land quiver can be neglected;

F. The voltage of the secondary electromagnetism interference induced in the system shall no more than 1.6kV.

1.4.2 Special Operating Conditions

According to IEC60694, GB/T11022, the manufacturer and user may agree on special service conditions whic h

deviate from the normal service conditions.

To prevent the condensation phenomena,the heater is necessary for switchgear and needs to be put into service

when the switchg ear is in readiness and service conditons. The heat dissipation problem of switchg ear can be

sloved by ventilation facilities.
2 .Technical Parameters

Switchgear Technical Parameters

3. Switchgear Structure and Equipment Installed

3.1 Basic Structure

(Figure 3/1)

The basic structure of KYN61-36 Switchgear comprises the panel itself, and the movable, withdrawable part wit h

circuit breaker, fuse or other facilities. According to the electrical function inside the panel, it consists of four

compartment , that is, busbar compartment A, circuit breaker compartment B, cable compartment C and low

voltage compartment D, which is showing in Figure 3/1. The whole panel is construct ed by bolting up the

double folded steel plates manufactured through cold rolling process and CNC machining equipment.

The withdrawable parts of the switchgear panels can be fitted with VCB, PT, surge arrester, fuse, isolated truck

and so on.

The indicator which is used to monitor the situation of primary circuit can be mounted in switchgear.This device

is composed by two parts: high voltage sensor and indicator. Sensor is mounted on the high voltage compart

ments for monitoring while the indicat or is mounted on the relay plate.

The affect of inner fault arcing of switchgear is taken into consideration during KYN61-36 being desiged and the

arcing test has been done according to the stipulati ons of IEC62271-200 and clause 7.15 in GB3906, which can

ensure the safety of operator and equipment.

The dimensions and weight of switchgear are as following:

Figure 3/1 KYN61-36 Air-insulated metal-clad withdrawable Switchgear, Section View.

(Fitted with VD4-36E, V -36 Withdrawble D4 Vacuum Circuit Breaker)

3.2 Enclosure and Partitions

The enclosure and internal partitions of the switchgear consist of high quality aluminium -clad zink plate. The

switchgear has degrees of protection IP4X for the enclosure and IP2X for the partitions.

The front door and rear door of the switchgear are throughly disposed to prevent corrosion,and then painted

with a special process which make it had a particular resistance to impact s and corrosion.

The circuit breaker compartment, busbar compartment and cable compartment are fitted with pressure relief

plates.These plates open upward if internal fault arc result in overpressure.This method of construction pre

vents them from danger and ensure operators in a safe condition all the time.

3.3 Compartment

3.3.1 Circuit Breaker Compartment

(Figure 3/2 , 3/3)

The circuit breaker compartment is fitted with the necessary guide rails to accommodate the withdrawable

part,which can be moved betw een the service position and the test/disconnetct ed position.

If the withdrawable part is moved from the service position into the test/disconnected position, the fixed

contacts located in the connection block in busbar compartment C and cable compartment D are automati -

cally covered by metal plates which will be interloc ked mechanically or can be locked by a padlock when the

withdrawable part is moved away. In the test/disconnected position, the withdrawable part is still completely

inside the panel with the door closed. The switching operations (including manual operation) are carried out

with th e doors closed.

3.3.2 Withdrawable Part

(Figure 3/4 , 3/5)

The manually moved withdrawable part consists of a robust sheet steel structure on which the circuit breaker

poles are mounted and the breaker mechanism with relevant compo nents is installed.

Contact arms with spring-loaded contact systems are fitted to the circuit-breaker poles.These create the electri

cal connection to the switchgear when the withdrawable part is inserted into the service position. Detailed

information on the vacuum circuit breaker can be found in the corresponding instruction manual.

The signalling, protection and control wiring between the switchgear and the withdrawable part is coupled by a

multiple pin control wiring plug.

As soon as withdrawable part has been slid into the switchgear and its interlock yoke has engaged in the test /

disconnected position, it is positively connected to the switchgear panel. At the same time, it is earthed by

earthing contacts and earthing rail. The position of withdrawabl e part can be checked on the electrical positio n

indicator or through the sight glass in the door at any time. The stored -energy spring mechanism of the circuit

breaker including controls and indicators is accessible at the front of the withdrawable part. Apart from the

version with a fitted circuit breaker, withdrawable parts with other equipment such as voltage transforme r, are

available.

3.3.3 Busbar Compartment

Busbars are laid in sections from panel to panel,and are held in place by the tee-off conductors and by busbar

bushings. The conductor mat erial used is tubing with a D-shaped cross section, in eith er singl e or doubl e

configuration depending on the current rating. The connection to the flat tee-off conductor s is made withou t

any special connecting clamps. The busbars and tee-off conductors are covered with shrink-on sleeves. The

bolt connections in the busbar system are normally covered by insulating covers. In conjunction with bushings ,

panel by panel partiti oning is realised .

The main busbar can be fitt ed with either single and double form or aluminium rectangle type according to the

client s requirements.

3.3.4 Cable Compartment

(Figure 3/6)

Current transform ers and an earthing switch (with manual operating mechanisms) are located here.Installatio n

of surge arrestor is possibl e. Multipl e parallel pow er cables can also be available without difficulty. The cable

sealing ends can be fitted in particularly favourable conditions. A removeable plate for cable glands is located in

the cable entry area.

Installation of voltage transformers at cable side of the panel is in preparation and will have influence on the

depth of the panel.

The earthing switch is designed with a making capacity of 62.5 kA (design for 80 kA in preparation).

3.3.5 Low Voltage Compartment

(Figure 3/7)

The low voltag e compartm ent, tog ether with its front door, accommodat es the secondary equipment of the

switchgear panel required for the particular application.

The control wiring in the switchgear panel area is led through generously dimensioned and metal covered

ducts. The left hand duct is reserved for the incoming and outgoing control wires, and the internal wiring in the

panel is located on the right hand side.

At the top of the left hand duct, an entry for control cables is reserved with the free-cut rubber sealing which will

keep the protection class IP4X for the whole encloser of the switchgear panel.

3.4 Interlocks/Protection Against Maloperation

A series of interlocks are provided to prevent fundam entally hazardous situations and mal-operation,thus pro

tecting both personnel and the switchgear itself. The interlocks which are normally individually effective are as

follows:

The withdrawable circuit brea ker can only be moved from the test/disconnected position into the service

position (and back) with the circuit breaker open and the earthing switch open (Mechanical interlock).

The circuit breaker can only be closed when the withdrawable circuit breaker is precisely in the defined test

position or service position (Mechanical interlock).

The circuit breaker can only be opened manually in the service or test position when no control voltage is

applied, and can not be closed (Electromechanical interlock).

The circuit breaker can be only closed when withdrawable circuit breaker is in the test/disconnected position

or removable position (Mechanical interlock).

Earthing switch can only be closed when the withdrawable circuit breaker is in the test/disconnected position

or the removed position (Mechanical interlock).

The withdrawable circuit breaker cannot be moved from the test/disc onnected position into the service posi-

tion when the earthing switch is closed (Mechanical interlock).

The circuit breaker control cable plug be locked when withdrawable circuit breaker is in the service position.

4. Major Electrical Components of Primary Circuit

All the electrical components be fitted in the KYN61 type switchgear are manufactured by Farady or from the

acknowledged supplier of Farady By this way , it can guarrant the consistancy of technical charac -teristic of

KYN61 type switchgear, matching well, then ensure the KYN61 type switchgear to be the advanced techinical,

stable characteristic and saft, reliable distribution equipment.

The below is the abstract of primary circuit main electrical components be fitted in switchgear.

4.1 Vacuum Circuit Breaker

(Figure 4/1 to 4/4)

Vaucum circuit breaker is one of the main electical components in the switchgear VD4-36E, VD4-36 is the latest

36kV withdrawable type vacuum circuit breaker which are manufactured by Farady, and all the products

are according to the requirements of international and national standard.

VD4 vacuum circuit breaker can be operated frequently and multiple break the short circuit current in the scope

of service current. It is suited to reclosed operation and has a extreme high operation reliability.

Circuit breaker can service safely, relibly when it be used in the scope of allowed techinical specification under

the normal service condition, and only needs a little maintenance as sweeping and lubricate.

The operating mechanism which matches VD4 vacuum curcuit breaker is charging spring operating mechanism.

This charging spring operating mechanism has a compact structure, stable characteristic and it also operates

three phase interrupter.The charging spring has two charging ways: manual and electrical.

The basic functions of operating mechanism can satisfy all clients requirement s, and it has the perfect, reliable

electrical and mechanical auxiliary elements.The detailed servicing priciple please see the electrical circuit diagram.

Figure 4/3 VD4-36E,V -36 D4 Withdrawable Vacuum Circuit Breaker Electrical Circuit Diagram
Figure 4/4 The Relationship Between Allowed Breaking Times N and Breaking Current of Withdrawable Vacuum Circuit Breaker