KYN28A-24(SDK1-24) Metal-clad AC Withdrawable Switchgear

KYN28A-12(GZS1 -12) Indoor AC metal-clad withdrawable switchgear (Hereafter referred to as”switchgear”) is an advanced medium voltage switchgear, developed by Xi’an Senyuan corporation. We had developed the miniaturization withdrawable switchgear cabinet of 650width based on their technologies. It is suitable for the applications in three-phase AC electric power system with rated voltage of 12kv and rated frequency of 50Hz, for the acceptance and distribution of the power, and also provides control, protection, and monitor of the circuit. Technical transferred is also provided by the same corporation.

1. Working environment

a.Environmental temperature: -10″0 〜40″0

b. Environmental humidity: the daily average value should be no greater than 95%, the monthly average value should be no greater than 90%. 2

c. Altitude: lower than 1000m.

d.Earthquake proof degree: earthquake intensity no more than 8 degrees.

e. The around atmosphere should not contain distinct pollutions such as corrosive or flammable gas or steam..

f. No severe contamination or frequency severe vibration, and the design of rigid grade under rigid condition should meet the requirements of grade 1.

g. lf the working conditions can not meet the environmental requirements of GB3906, please negotiate with the manufacturer. Notes: Electric heater should put in operation when relative humidity exceeds 70%.When working site is beyond the altitude of 1000m, it should conform to national standard.

                      VS1 indoor vacuum circuit breaker (front and side view)                                             

 VS1 indoor vacuum circuit breaker  150mm vs 650mm width

2. Applicable standards:

• GB3906-2006: AC metal-clad closed switchgear and control equipment 3.6kV-40.5kv

• GB11022-1999: General technical qualification of high-voltage switchgear and control equipment

• IEC62271 -200/2003: AC metal-clad close switchgear and relevant control equipment with rated voltage between 1 kV and 52kv

• DL/T404-2007: AC metal closed switchgear and control equipment 3.6kV-40.5kv

3. Technical parameters:

3.1 Technical parameters of switch equipment, refer to Table 1

					Table 1
Item		Unit	Parameter
Rated voltage		kV	3,6,7.2,12
Rated frequency		Hz	50
Rated current of the circuit breaker		A	630,1250,1600,2000,2500,3150
Rated current of the switch cabinet		A	630,1250,1600,2000,2500,3150
Rated thermal current (4s)		kA	16,20,25,31,5.40,50
Rated dynamic current (peak value)		kA	40,50,63,80,100,125
Rated short circuit drop out current		kA	16,20,25,31.5,40,50
short circuit making current (peak value)		kA	40,50,63,80,100,125
Rated insulation ability	1min power frequency withstand voltage	kV	24	32	42
	Lightening impact withstand voltage	kV	40	60	75
protection degree		IP4X for shell,and IP2X When breaks room door is open

3.2 Technical parameters of VD4、 VS1-12 vacuum circuit breaker and FP series sulfur hexafluoride circuit breaker

a. Technical parameters of VD4^ VS1-12 vacuum circuit breaker and FP series sulfur hexafluoride circuit breaker, refer to Table 2

Table 2
Item		Unit	Parameter
Rated voltage		kV	3,6,7,2.12
Rated frequency		Hz	50
Rated current of the circuit breaker		A	630,1250,1600,2000,2500,3150
Rated thermal current(4s)		kA	16,20,25,31,5.40,50
Rated dynamic current(peak value)		kA	40,50,63,80,100,125
Rated short-circuit drop out current		kA	16,20,25,31.5,40,50
Short-circuit making current (peak value		kA	40,50,63,80,100,125
Rated insulation ability	1min power frequency withstand voltage	kV	42
	Lightening impact withstand voltage	kV	75
Rated operating sequence		kA	breah-0.3s-close breaking-180s-close breaking
Rated short-circuit current making time		time	50
Mechanical life		time	20000

Table 3
ltem		Unit	Parameter
Switching distance of the contact		mm	11±1
Contact exceed range		mm	4±0.5
Center distance between phases		mm	150±0.5,210±0.5,250±0.5,275±0.5
Closing contact bounce time		ms	<2
Different period of three-phase break	brake	ms	<2
reak brake time when voltage	Max	ms	<50
	Rated	ms	<50
	Min	ms	<60
Making time		ms	C100
Average opening speed		m/s	0.9-1.2
Average opening speed		m/s	0.6-0.8
Circuit direct current resistance of each phase		0	<40
Contact pressure		N	3200±100

When the circuit breaker is applied to control 3-1 Okv electromotor, AC 600A, a metal-oxide surge arrester must be installed;clients can consult with manufacturer for the detailed requirements. When the circuit breaker is aplied to cut off the capacitor the group, the rated current of capacitor group should not be the circuit breaker.

3.3 Technical parameters of operation mechanism, refer to Table 4

Item		Unit	Value
Rated operation voltage	Closing coil	V	DC220.110 AC220,110
	Opening coil	V	AC220.110 DC220,110
Coil power	Closing coil	W	245
	Opening coil	W	245
Power of energy storage moto		W	50
Rated voltage of energy storage motor		V	DC220,110,AC220,110
Time of energy storage		S	<10

4. Structure

              A-Busbar room                                                                      B-Circuit breaker handcart room

              C-Cable room                                                                       D-Relay instrument room

              1- Shell                                                                                 2- Branch busbar

              3- Busbar bushing                                                                4- Main busbar

              5- Static contact box                                                             6- Static contact

              7- Current transformer                                                          8- Earthing switch

              9- Cable                                                                               10- Arrester

             11- Earthing main busbar                                                      12- Removable clapboard

             13- Separator (Valve)                                                            14- Secondary plug

             15- Circuit breaker handcart                                                 16- Heating device

             17- Withdrawable horizontal baffle plate                               18- Operation device of earthing switch

             19- Secondary trunking                20- Soleplate                    21- Pressure release device

5. Streucture overview

The switchgear is designed according to GB3906 metal-clad closed switchgear. It composes of a main body enclosure and a withdrawable component (called handcart). The enclosure is divided into four separate rooms. The protection lever of the shell will be IP4X, and if the door of separate room or breaker room is open, then the protection lever should be IP2X. There are several functional schemes such as overhead inlet and outlet overhead line, inlet and outlet cable, forming a whole electric power distribution system device. This switchgear can be installed, commissioned and maintained from the front, which makes it possible to be arranged as back-to-back, side-to-side, or against the wall.

5.1 Shell and auxiliary

The main body enclosure formed by import zinc steel plate coated with aluminum, double-bented by CNC machine. Owning to this advance process, the cabinet gains less weight, higher mechanical strength and more artistic outward appearance compared with other products, as well as the advantage of higher precision, strong anti-corrosion and anti-oxidation capacity. The cabinet adopts assembling configuration. It is connected with high intention nuts and bolts, thus the process manufacture period is shortened, while occupying less area, the components are highly optimized for general use, so it is easier for organization.

5.2 Handcart

The framework of handcart, alike the cabinet, is formed by steel plate, and processed by CNC machine. The handcart is insuloted from the cabinet when combined. The mechanical interlock is safety, reliable and flexible. Based on the different usage, there are circuit breaker handcart, potential transformer handcart, measure handcart and separate handcart. All kinds of handcart can be organized on basis of modulus. The same type of handcart can be replaced. In cabinet, handcart may be at break position, testing position, or working position, each one has its own locating device to ensure reliable interlock followed by the operation procedure to prevent interlock disoperation. All handcarts are fixed by nut or spindle, so the operation is convenient and flexible for all operators. The handcart can be easily drawn out from the cabinet for inspection and maintenance. Due to the withdrawable adoption, it saves space and is easily to be inspected and repaired.

5.3 Separate room

Each main electric unit has a separate room, that is, circuit breaker handcart room, busbar room, cable room and relay control room.All the rooms can achieve IP2X protection level. Except for the relay control room, the other three separate rooms are equipped with a release pathway. Owning to the withdrawable type, the increased cable room enable the multiple cable are connected.

5.4 Interlocking device to prevent fault operation

Metal clad switchgear is equipped with reliable interlocking device, satisfying the “Five Standards** .

a. There is an obvious button or KK type alternation switch to prevent fault operation.

b. Only when the circuit breaker handcart is under test or operation site, the circuit breaker can be used to switch on or switch off. In addition, the handcart is not able to move while the circuit breaker is switched on. It helps to stop on-load wrong operation.

c. Only when the earthing switch is on the breaking site, the circuit breaker handcart is able to be moved from the breaking or test site to operation site. Only when the circuit breaker handcart is on the test or breaking site, the earthing switch can be switch off (the earthing switch can be fitted with voltage indicator). Thus it helps to avoid switching off the earthing switch when under hot line, as well as switching on the circuit breaker when earthing switch is on closed site.

d. In order to prevent the staff access to the area, the bottom door and back door cannot be open when the earthing switch is on breaking site.

e. When the circuit breaker handcart is located on the test or operation site without control voltage, it can only be operated by manual mode, not automatic mode.

f. When the circuit breaker handcart is on the operation site, secondary plug is locked and not able to be pulled out.

g. Electric interlock is applied for each cabinet. The switchgear can be equipped with electromagnet locking device on the earthing switch to improve reliability. Customers choose whether they need it or not.

5.5 Pressure relief device

There are pressure relief devices installed in the circuit breaker room, busbar room and cable room. When the inner fault occurs with arc, pressure inside the cabinet will increase. Then the special preassemble gasket on the door seals the cabinet in the front. Finally the pressure relief device on the top open automatically to release the pressure, ensure the safety of operator and switchgear itself.

5.6 Secondary plug and handcart interlock

The secondary circuit of switchgear and handcart are interlocked through manual secondary aviation plug. Moving-contact from secondary plug is connected with circuit breaker handcart by nylon corrugated expansion pipe. The secondary static contact base is fixed on the top right of the handcart. Only when the handcart is set on the test or breaking site, the secondary plug can be plugged in or pulled out. When the circuit breaker handcart is on the operation site, the secondary is locked and cannot be pulled out since the function of mechanical interlock works. As the closing mechanism of circuit breaker handcart is locked by the electromagnet, the handcart is only able to be switched off when the secondary plug is disconnected.

5.7 Charged display device

There is a charged display device for testing the primary circuit if customer requires. This device consists of high pressure sensor and portable display. They are connected together with wires as a whole. It not only shows the high pressure circuit status, but also can be cooperated with electromagnetic lock to force earthing switch handle and net door locked. This manner helps to prevent switching off earthing switch with live and accessing into the live zone, to avoid faulty operation.

5.8 Condensation and corrosion prevention

In order to avoid danger when operating in the high humidity and large fluctuations temperature, heater is installed in the circuit breaker room and cable room separately, to prevent corrosion in above environment.

5.9 Earthing device

There is an individual earth copper busbar with a dimension of 5X40mm2 in the cable room which is going through adjacent switchgear, and has a good contact with the switchgear body. This busbar is used for components that are earthing directly. Meanwhile, since the whole switchgear body is made up of aluminum zinc plate, it makes a good earthing status to protect the operator and switchgear.