Product Introduction

ZHN3-72.5 Cubical Type Gas Insulated Metalclad Switchgear (C-GIS) is a new environmental product designed and developed independently by our company, firstly using in embedded circuit-breaker pole technology of the vacuum interrupter in the products of 72.5kV and filling the gaps in this field in China. It can be widely uses in various fields of national economy, such as distribution and transformer substation, city power supply grid, large industry and mine enterprises, petrochemical industry, metallurgy, and railway, etc.

ZGN3-72.5 Switchgear is a new generation of H.V. products combined with vacuum-interrupting technology, embedded CB pole technology, gas insulation technology.

According to the requirements of environment protection and avoidance of greenhouse effects, low pressure (0.02MPa) SF6, which is only a few amount, has been used as the insulation gas between phases and from phase to earth. The adoption of vacuum interruption avoids generation of the poisonous gas, and the use and emission of SF6 can be greartly reduced. Therefore, it is friendly to environment. It is of metalclad gastight design. All the high voltage components are completely sealed in the gas tight box, with no surrounding influence and maintenance free.

ZHN3-72.5 Switchgear adopts intelligent control and protection units, which have powerful functions of control, protection, and measurement to meet requirements of automatization in the electricity distribution grid. It has been designed in compliance to the Chinese standards of GB11022, GB7674 and GB3906, IEC62271-100, IEC62271-203etc. ZHN3-72.5 Switchgear passed all the type tests and evaluation for new product technology.

Main Features

Environmental protection

ZHN3-72.5 switchgear designed with Vacuum Circuit Breaker, no SF6 could be emission, The leakage of SF6 is extremely lower due to the low pressure in the gas boxes. Service life of SF6 could be enough for 30 years without air supply. SF6 as the insulation gas doesn’t participate in extinguishing the arc so protection product has obtained national level certification.

Miniature

ZHN3-72.5 switchgear use SF6 as insulation gas, and interrupt with VCB. As a result, the tank has limited size, small area and compact structure. Moreover, transportation is convenient with light weight.

Easy operation and installation

The modular design of ZHN3-72.5 switchgear provides dielectrically sealed plug-in connections for the voltage transformers, cable bushings and bus bar bushings assembled outside the gas tank, which is more flexible for the installation and replacement. The panels can easily be connected to each other by a bus bar silicon connection.

Maintenance

All high voltage components are completely sealed in the gastight box, therefore it is of no influence upon the serious surrounding conditions. Any accidents caused by congeal dew, dust, moist, chemical vapors or small animals are excluded forever. The installation, operation, expansion and replacement of the switchgear can be undertaken without operation of SF6.

Laser welding technology has been used to the stainless steel boxes, so the yearly leakage rate of SF6 is less than 0.5%. ZHN3-72.5 switchgear combines the most modern vacuum interrupter technology, the embedded pole design and a reliable spring drive so that highest breaking currents and a high reliability and achieved. The vacuum circuit breaker pole is maintenance free for the lifetime of the switchgear.

Safety and Reliability

The circuit breaker with the embedded pole and the three positio0n switch can be operated manually or by a motor drive, the complete Five-Prevention mechanical interlocking can avoid misoperation. It is safe and touchable because all high voltage components including cable plugs, and CT are completely sealed in the shell earthed to the ground. The protection degree of all the high voltage parts in the primary circuit is IP65 and the protection degree of the shell is IP40.

The body of the gas tank is manufactured by a highly advanced laser cutting and laser welding process. After assembly, all tanks are checked for leaking by a helium leakage detecting system imported from Germany. The gas boxes are gastight for the lifetime. The quality control is in compliance with ISO9001 standards and the National Appraisal Certificate was acquired for the new patented ZHN3-72.5 switchgear.

Technical Parameter

Product Structure

ZHN3-72.5 switchgear is of two gas tank structure. The upper gas tank is the VCB tank and the lower gas tank is the bus bar and EDS tank. Both the gas tanks are made of nonmagnetic stainless steel plate, which is laser-cut and laser-welded. The upper and low gas tanks are connected by the bus bar connector. All the non-welded connection sections are sealed by the rubber sections are sealed by the rubber O-rings.

The high voltage parts are of complex design. The disconnector and earthing switch are compounded to be three-position (EDS), assembled beside the bus bar with the same moving contact. CB and EDS drives are installed in the front-upper position. Both two drives can be operated manually or by motor.

The inner cone cable flange plates are placed on the lower-rear and upper-rear sides of the CB box, which can be used to connect cable, PTs, SAs., and CTs.

The switchgear is modular designed with three-phase-in-one-box structure, which is formed by CB function unit (gas tank), low voltage compartment (instrument, operation drive compartment) and cable room, etc. The low voltage compartment is in front of the panel. Frame is under the gas tank and supports the box. The core parts are CB function unit (gas tank) and three-position switch and bus bar unit (gas tank). The gas manometer and manometer with temperature compensation function are equipped in the switchgear, which are used to monitor the gas pressure inside of the box.

The gastight box is equipped with gas-filling valve and pressure relief device. Rubber O-rings are used for the static seal. The special designed rubber rings and gastight microplasma welded bellows are used for the dynamic seal.

The shells of each gas box, low voltage compartment and the doors of each compartment are well earthed according to the regulations, and marked with the signs of “ Earthing protection”.

Scheme