Type ZF32—126(L)(G)/T2500—40gas-insualed metal-enclosed switchgear ( namely GIS, hereinafter referred as to the product) adopts three phase common tank structure, it consists of several standard functional modules such as circuit breaker, disconnector/earthing switch, current transformer, voltage transformer, lightning arrester, bushing or cable terminal and connector etc. Since connection flanges of all the modules have the same sizes, these functional modules can be assembled at will to meet user’s requirements of different scheme designs and layouts.
The product uses SF6 gas as the insulation and arc-extinguishing medium, the circuit breaker adopts self-energy arc-extinguishing principle, and is equipped with a spring operating mechanism. The disconnector and earthing switch are integrated into a module, can be equipped with a motor operating mechanism or a spring operating mechanism.
The product is widely used in these fields of A.C. 50Hz，110kV power system such as substations, power plants, petrol-chemical, steel and coal, railway industries and urban power supply. It has these advantages small land area, high reliability, short installation time and small operation and maintenance workload. It is especially suitable for urban substation with land shortage, hydropower plants in mountains and the heavily polluted area as measurement, protection and control of the power equipment in the power system.
（1）Small volume, with a bay width of 1200mm. The three-phase common tank design adopted saves space, reduces the quantity of parts, increases reliability, and effectively reduces the land area. The arrangement is more flexible to lower the construction cost.
（2）Light weight, low temperature rise, anti-corrosion and aluminum-alloy enclosure. The weight of a standard circuit breaker bay is about 3.5 tons, The loss of eddy current on the enclosure is small, so the temperature rise on the enclosure is almost not affected by current-through, this improves the corrosion resistance of the equipment.
（3）Convenient transport and easy installation: Each bay is the modular structure, so it can be transported in whole. Secondary cables and the mechanism are all already connected and made commissioning at factory, so site installation is easy and the installation time is very short.
（4）Excellent breaking capacity: Using SF6 gas as the insulation and arc-extinguishing medium and the self-energy arc-extinguishing principle can ensure to break different fault currents. The disconnector can meet the requirements of switching busbar transfer current and busbar charging current; the earthing switch can meet the requirements of making short circuit current and switching inductive current.
（5）Reliable insulation and current-carrying capacity: Since electrical components are in SF6 gas isolated from air, the insulation is reliable. SF6 gas characteristics don’t fall with time, so contacts are protected from oxidation and other chemical reactions. no mater it is stable reaction or invert reaction.
（6）Good tightness: Each gas compartment has a set of seals, and there are two sets of seals outside the compartment, one is main seals, there is a set of water-proof and dust-proof rings added to the outside of the main seals(the design of sealing slots is optimized, both compression and filling are just right, so it can not only seal gas without leakage but also ensure that the O-rings have no plastic deformation within the range of elastic deformation, this is good for the life of the O-rings, the aging life can be up to 20 years.) SF6 system adopts the decentralized monitoring way, SF6 valves and pipelines are already removed. Because of using the new self-sealing connectors and the on-line calibrated SF6 density relays, the GIS leakage from outside is avoided. Therefore, GIS leakage rate is lower; its tightness is much higher than that required by the national standard.
（7）Safe and reliable: The whole enclosure is completely earthed. Electrically, the whole equipment can withstand 1.3 times phase voltage at zero gauge pressure; mechanically, the rapture pressure of the enclosure is 3.5 times the design pressure. User can add rapture disks when necessary to ensure the personnel and equipment are safe.
（8）trong adaptability and excellent earthquake resistance: can withstand earthquakes with a intensity of 9°. Porcelain bushings are anti-pollution, creep age distance is 31mm/kV, and can meet the requirements of the IV polluted area.
Rated short time withstand current（4s）
Rated peak withstand current
Rated short time power frequency withstand voltage, between phases and to earth
Rated short time power frequency withstand voltage, Across isolating distance
Rated lightning impulse withstand current, between phases and to earth
Rated lightning impulse withstand current, Across isolating distance
Power frequency withstand voltage on auxiliary and control circuit （1min）
SF6 gas pressure( gauge pressure, at 20℃ ) , Rated pressure
0.6 0.4 0.5
SF6 gas pressure( gauge pressure, at 20℃ ) , Alarm pressure
0.55 0.35 0.45
SF6 gas pressure( gauge pressure, at 20℃ ) , Lock-out pressure
SF6 gas manual leakage
Moisture in gas compartment, Handover acceptance value
Moisture in gas compartment, permissible value in service
three phase common tank