KYN28-12(GZSI-12Z)Armoured Middle-Mounted Metal Enclosed Switch 1.General KYN28-12 armoured middle-mounted metal enclosed switchgear (hereinafter referred to as switchgear) is a new product with own design and development on the basis of absorbing advanced technology abroad, it can replace the old metal enclosed switchgears, such as KYN1-10, JYN2-10, GBC-10 series, etc. The shell is bolted by Al-Zn alloy coated steel plates which are formed after multiple bending by CNC machine tool to ensure not only the high mechanical strength, but also the tidy and beautiful product. The door is plastic sprayed to ensure the high impact resistance and corrosion resistance ability. The protection level of is IP4X. The main switch can be configured VD4-type vacuum circuit breaker, C3 series fixed load switch, meanwhile, it also can be assembled several domestic vacuum circuit breakers (such as VS1, VH1, VK, ZN28) to replace the similar products. No matter which kind of circuit breaker is chosen, the air insulation distance should be more than 125mm, the composite insulation distance should be greater than 60mm. There are interlock protection functions to prevent operating CB trolley with load, prevent misoperation of CB, prevent closing CB with earthing switch closed, prevent entering electrified chamber and prevent closing earthing switch with power. 2.Model Definition
3.Operational Environment a. Ambient Temperature: -10 ~+40 b. Relative Humidity: Daily average should be less than 95%, monthly average is not more than 90% c. Altitude: Not higher than 1000m d. The seismic intensity should be less than 8-magnitude. e. It should be operated in the place without danger of fire, explosion, serious dirtiness, chemical corrosion and acute shaking. If it is planed to operate in the condition out of the above limits, the customers should negotiate with us to decide the allowable operational conditions and technical measures. 4. Technical Parameters Item Unit Parameters Rated voltage kv 3, 6, 7.2,12 Rated frequency Hz 50 CB rated current A 630, 1250, 1600, 2000, 2500, 3150 Switchgear rated current A 630, 1250, 1600, 2000, 2500, 3150 Short-time withstand current ka 20, 25, 31.5, 40, 50 Rated dynamic stability current(peak) ka 50, 63, 80, 100, 125 Rated short circuit breaking current ka 20, 25, 31.5, 40, 50 Rated short circuit closed current ka 50, 63, 80, 100, 125 1min power frequency withstand kv 24, 3, 42 Rated insulation grade voltage Lightning impulse withstand voltage kv 40, 60, 75 Protection level Shell: IP4X, isolation chamber and CB chamber door opened: IP2X.
5. Switchgear Schematic Diagram A Busbar chamber B CB Chamber C Cable Chamber D Relay instrument chamber 1 -Shell 2 -Branch bar 3 -Busbar 8 -Zinc oxide arrester 9 -Base plate 13-Earthing switch operating mechanism 14-withdrawable horizontal clapboard 4 -Isolated contacts 5 -Contact box 6 -Earthing switch 7 -Current transformer 10-Master grounding busbar 11-The control line slot 12-Cable seal terminal 15-Wire rod mechanism 16-VCB 17-Wiring plug 18-Terminal board
19-Shutter 20-Loading and unloading type clapboard 21-Pressure release 6. Overview of switchgear structure CB chamber Railways have been installed on both sides of chamber, the trolley slides on it from disconnecting/testing position to working position in cabinet. The shutter of fixed contactor box has been installed behind the trolley chamber. when moving trolley from opening/testing position to working position, the shutters of upper and lower fixed contactor box opened together automatically and closed automatically if move trolley from working position to disconnecting/testing position, they will cover fixed contactor box completely until the trolley has been moved back to specified position and ensure effective isolation. At the same time, because the upper and lower shutters can not be moved together, so the maintenance people may lock the shutter of electrified side to keep them away from electrified part. The trolley may be operated when the door of circuit breaker chamber closed. The maintenance people may observe the trolley s location, closing and opening indication and charging condition through window on door. Busbar chamber Main busbars are connected together and run through switchgear, which fixed by branch busbar and fixed contactor box. The main and inter busbar are copper material with rectangle section, and adopted double busbars due to high current load. The branch busbar is connected to fixed contactor box and main busbar by bolts, it needn t other support. For special requirement, the busbar can be covered by heat-shrinkable bush, insulating bushing and side-cap. The busbar of neighboring cabinets are fixed by bushing. The air-cushion kept between inter busbars will prevent busbars from melting if internal fault arc appears. The bushing will limit failure effectively not expanding to other switchgear. Cable chamber The switchgear is adopted central-mounted type, so the cable chamber has enough space. The current transformer and earthing switch have been mounted behind chamber. Lightning arrestor has been mounted on back and low part of chamber. The builder will enter cabinet from front to install and maintain after moved trolley and withdrawable clapboard away. The switchgear connected with cables is equipped with movable non-metal or non-magnetic metal seal plates with crack at the bottom to ensure the convenience to construction. Relay and instrument chamber
The relay and instrument chamber can be installed with protective elements, meter supervision indicator and secondary equipment with special requirement. The control wires were laid in wire slot with enough space, and covered with the metal plate to separate secondary wire and HV chamber. The holes have been reserved at the roof of relay and instrument chamber for construction of small busbar. When wiring, the roof plate of meter chamber can be rotated, that is convenient to install small busbar. 7. Interlock protection 1. The circuit breaker only can be closed and opened when the circuit breaker trolley is at testing or working position and the trolley can not be moved after closed circuit breaker, this function prevents pulling and pushing circuit breaker with load. 2. The circuit breaker trolley only can be moved from testing/opening position to working position when the earthing switch is at opening position. The earthing switch only can be closed (may be fitted with charged display device) when circuit breaker trolley is rotated to testing/opening position. This function prevents earthing switch from mistake-closing with load, and prevents maintainer from closing circuit breaker while the earthing switch was on closing position. 3. The back door and lower door can not be opened when the earthing switch is at opening position, and this function prevents maintenance people from entering working compartment (electrified) in error. 4. When the circuit breaker trolley is rotated to testing or working position without control voltage, and it can only be opened manually, but not closed. 5. When the circuit breaker trolley is at working position, the secondary plugs has been locked and can not be moved. 8. Installation Dimensions Switchgear usage Width Wire in and out at bottom depth Wire in and out on top depth Zn63 800 1500(1550) 1660 3AH, ZN12 800 1500(1550) 1660 VD4, VS1 800 1500(1550) 1660
Switchgear usage Width Wire in and out at bottom depth Wire in and out on top depth W-VAC 700 1660 1660 CB 800 VCP-W 800 1660 1660 9. Ordering Instructions Orderers should offer the following technical information: a. Main wiring diagram plan No., use and single-bus diagram, the diagrams of rated voltage, rated current, rated short-circuit breaking current, distribution room layout and switchgears arrangement diagrams, etc. b. The switchgear control, measurement and protection functional requirements; other locking and automatic device requirements and schematic diagrams c. The type, specification and quantity of main electrical elements installed in the switchgear. d. Other special requirements.