Product Introduction

KYN28-12 armored retractable enclosed switchgear, suitable for three-phase AC power systems with a rated voltage of 12kV and a rated frequency of 50Hz, used for receiving and distributing electrical energy and for controlling, protecting, and monitoring circuits.

Meeting standards:

GB3906-2006 "3.6~40.5kV AC Metal-Enclosed Switchgear and Control Equipment"

GB11022-89 "General Technical Conditions for High-Voltage Switchgear"

IEC298 (1990) "AC Metal-Enclosed Switchgear and Control Equipment with Rated Voltage Above 1kV and 50kV and Below"

DL404-97 "Technical Conditions for Ordering Indoor AC High Voltage Switchgear"

Model meaning

Functions and Features

The switchgear is designed according to the armored metal-enclosed switchgear in GB3906-91. The whole consists of two main parts: the cabinet body and the center-mounted retractable components (i.e., the hand cart). The cabinet is divided into four separate compartments, with an enclosure protection rating of IP4X, and the doors between small compartments and the circuit breaker chamber are rated IP2X when opened. It features overhead incoming and outgoing lines, cable inlet and outlet lines, and other functional schemes. After arranging and combining, it forms a complete power distribution system device. This switchgear can be installed, debugged, and maintained from the front, allowing for back-to-back, dual-arranged, and wall-mounted installation, which improves the safety and flexibility of the switchgear and reduces the footprint of the switchgear.

◇ Enclosure and others

The main cabinet frame of the switchgear is made of aluminum zinc coated thin steel plates, processed by CNC machine tools, and employed multiple folding edges. This gives the entire cabinet not only high precision and strong corrosion and oxidation resistance, but also, due to the use of multiple folding edges, makes the cabinet lighter, has higher mechanical strength, and an attractive appearance compared to other similar equipment cabinets. The cabinet adopts a modular structure, connected by rivet nuts and high-strength bolts, resulting in a short processing cycle, strong component interchangeability, minimal footprint, and convenient production organization.

◇ Handcart

The handcart frame is assembled from thin steel plates processed by CNC machine tools. The handcart is insulated with the cabinet, and the mechanism interlocks safely, reliably, and flexibly. According to usage, handcarts can be divided into circuit breaker handcarts, voltage transformer handcarts, metering handcarts, isolation handcarts, etc. Various handcarts can be adjusted according to modulus and building blocks, and handcarts of the same specification can be freely interchanged 100%. The handcart has disconnection, test position, and working position inside the cabinet. Each position is equipped with positioning devices to ensure reliable interlocking. Operation must follow the interlock error prevention procedure. All handcarts use nuts and lead screws to push and withdraw, making operation light and flexible, suitable for duty personnel. When the handcart needs to move the cabinet, a dedicated transfer cart can be used to easily remove it for various inspections and maintenance; It also uses a mid-mounted design, making the entire cart compact and easy to inspect and maintain.

◇ Partition room

The main electrical components of switchgear each have their own independent compartments, namely: circuit breaker handcart compartment, busbar compartment, cable compartment, and relay instrument compartment. The protection level between compartments reaches IP2X; Except for the relay compartment, the other three compartments each have their own pressure relief channels. Due to the centrally positioned layout, the cable compartment space is greatly increased, allowing the equipment to connect multiple cables.

a. Circuit breaker compartment

Tracks are installed on both sides of the isolation to allow the handcart 15 to slide from the disconnected and test positions to the working position inside the cabinet. The partition 13 (valve) of the stationary contact box 6 is installed behind the rear wall of the handcart compartment. When the handcart moves from the disconnected or test position to the working position, the valves on the upper and lower stationary contact boxes are linked with the handcart and automatically open; When moving in the opposite direction, the valve automatically closes until the handcart retracts to a certain position and covers the stationary contact box, forming effective isolation. Since the upper and lower valves can be operated separately, during maintenance, the live side valve can be locked, ensuring maintenance personnel do not touch the live body. When the door of the circuit breaker compartment is closed, the handcart can also be operated. Through the observation window of the middle door, the disposing and closing positions of the handcart inside the compartment and the energy storage status can be observed.

b. Busbar compartment

The main busbar 4 is a single unit spliced and connected through to each other. It is fixed by the branch busbar 2 and the stationary contact box. The main busbar and connecting busbar are rectangular cross-sectional copper busbars, and when used for high current loads, double busbars are assembled. The support busbar is bolted to the stationary contact box 6 and the main busbar, and does not require additional support. If needed, the busbar can be covered with heat shrink sleeves and connecting bolt insulation sleeves and end caps, and adjacent cabinet busbars are fixed with sleeves 3. This air buffer retained between connecting busbars can prevent melting in the event of internal fault arcs, and sleeve 3 can effectively contain accidents within the cabinet and prevent it from spreading to other cabinets.

c. Cable compartment

The switchgear is centrally positioned, so the cable room space is relatively large. The current transformer 7 and grounding switch 8 are installed on the rear wall of the compartment, and the lightning arrester 10 is installed at the lower rear of the compartment. After opening the cabinet door, construction personnel can enter from below to install and maintain the cabinet. The cable connection conductors inside the cable room can have 1~3 single-core cables parallel per phase. If necessary, 6 single-core cables can be paralleled per phase. The bottom of the connecting cable cabinet is equipped with removable non-metallic sealing panels or non-magnetic metal sealing plates with slits, making construction convenient.

d. Relay instrument room

The relay instrument room can be equipped with relay protection elements, instruments, live monitoring indicators, and required secondary equipment. Control wires are laid in cable trays with sufficient space and have metal cover plates, which isolate the secondary lines from the high-voltage chamber. The left cable tray is reserved for controlling the introduction and exit of small busbars. The control wires inside the switchgear cabinet are laid on the right side, and there is also a small busbar cross-hole on the top panel of the relay instrument room for easy installation. During wiring, the top cover plate of the instrument room can be flipped to facilitate the installation of small busbars.

◇ Prevents misoperation of the interlock device