The volume of CB trolley inside China KYN28A-12 Gas Insulated Middle-Mounted Metal Clad &
Enclosed HV Electrical Cabinet/Switchgear is small and weight is light. The space utility rate is high. Therefore, the size is easy to control and accuracy is high. The trolley which is driven by lead screw is moved in and out on the specialized guide rail. Therefore, the operation is easy.
When the CB trolley is at disconnected position, put it on the specialized service trolley whose height can be adjusted according to the height of ground and guide rail. The CB trolley is at middle part of switchgear, the lower part of switchgear can be cable chamber, therefore, cable connection space is enough and operation is convenient. There are “Five Preventions” interlocks. Market share of KYN28 switchgear which has been approved by specialists from home and abroad is high.
Our company changes the fixed VCB to drawer type CB. This scheme is applied for KYN28-12 middle mounted HV switchgears and there is “Five preventions” device to ensure the safety when maintenance people and operators doing maintenance work and decrease.
We added grounding disconnecting switch to every HV outgoing switchgear to prevent danger to maintenance people when supply power to maintenance line wrongly. There is good mechanical interlock for ground disconnecting switch and VCB so that the safety of operation is improved.
We add one PT cabinet to 11kV, 50Hz busbar system to provide protection voltage signal to power supply system. This optimized scheme ensures that every HV switchgear can get measurement signal sampling and protection signal sampling so that the grid and every switchgear can operate safely. The zero sequence voltage winding on PT uses open delta connection to detect insulation voltage of system effectively.
The system is set with zero sequence CT to monitor the zero sequence current of every circuit and judge which line is grounded together with line selection device for low current effectively(choosable).
For detail drawing, go to DOWNLOAD.