4.2　Installation and Adjustment

4.2.1　The foundation or support of the SF6 circuit breaker shall be installed in accordance with the technical documentations of the product，and meet the following requirements:

1　Concrete strength shall meet the requirements for equipment installation.

2　Based on the deviation of center distance and height should not be greater than 10mm.

3　Holes or embedded parts reserved centerline deviation should not be greater than 10mm；the upper end of foundation embedded parts shall be 1mm-10mm over the concrete surface.

4　Center line deviation of embedded bolt shall not be exceed than 2mm.

4.2.2　The following inspection shall be carried out before SF6 circuit breaker is installed:

1　Components of the breaker shall be complete，clean and intact.

2　Pressure value of the gas such as SF6 pre-charged in arc extinguish chamber or tank body and insulating post as well as water content of SF6 gas shall meet the requirements in the technical documentations of the product.

3　Field test shall be carried out for grading capacitance and closing resistance；technical values shall meet the requirements in the technical documentations of the product；inspection for grading capacitor shall meet the relevant requirements of Chapter 11 in this code.

4　Surface of insulating parts shall be free from cracks，peeling or damage，and with good insulation capacity；end connecting parts of insulating drawbar shall be firm and reliable.

5　Surface of porcelain bushing shall be smooth，and free from cracks and damage；flaw detection shall be carried out when appearance inspection is doubted.When porcelain bushing is adopted，cementing position between porcelain bushing and metal flange shall be firm，compact，and coated with good waterproof glue；when silastic bushing is adopted，its appearance shall be free from cracks，damage and deformation；the metal flange joint surface of bushing shall be flat，smooth，and free from damage or casting blister.

6　Operating device parts shall be complete；bearing shall be smooth and free from jamming；casting shall be free from cracks or poor welding.

7　Bolts，gaskets，sealing grease，detergent and lubricating grease for assembly shall meet the requirements in the technical documentations of the product.

8　Density relay and pressure gauge shall be inspected and provided with product qualification certificates and test reports.Connections between density relay and equipment SF6 gas pipes shall be able to be separated with the equipment pipeline system，in order to carry out on-site calibration for density relay.

9　Before tank-type breaker is installed，secondary winding sequence，transformation ratio，polarity and magnitude order of current transformer shall be checked to see whether the design requirements have been met or not.Conventional tests of current transformer such as transformation ratio and polarity shall be qualified.

4.2.3　SF6 circuit breaker shall be installed in the weather without wind，sand，rain and snow.When the arc extinguish chamber is inspected and assembled，relative humidity of air shall be less than 80% and measures such as dust-proof and damp-proof shall be adopted.

4.2.4　SF6 circuit breaker shall not be disassembled and inspected on site；when on-site disassembly must be carried out due to equipment defects，it shall be agreed by the manufacturer，instructed by the manufacturer's personnel or treated by the manufacturer's personnel.

4.2.5　Installation of SF6 circuit breakers shall be carried out under the instruction of manufacturer's technical personnel.Installation shall not only meet the requirements in the technical documentations of the product，but also meet the following requirements:

1　They shall be assembled by the parts serial number and sequence specified by the manufacturer，and shall not be assembled together.

2　Fixation of breakers shall meet the requirements detailed in the technical documentations of the product，and shall be firm and reliable.The gaskets between support（or underframe）and foundation should be less than or equal to 3 and the total thickness shall not be greater than 10mm；each gasket dimension shall match with the pedestal and be connected firmly.

3　Flange face of each in-phase post porcelain bushing should be arranged in the same horizontal plane；distance deviation between post center lines shall not be greater than 5mm；interphase center distance deviation shall not be greater than 5mm.

4　The installation positions of all parts shall be correct，of which the horizontal or vertical positions shall be kept according to the requirements detailed in the technical documentations of the product.

5　Surface of seal groove shall be clean，free from scratch and mark；used gasket（ring）shall not be reused；new gasket（ring）shall be inspected to see if it is damaged；when sealing grease is coated，it shall not flow into the gasket（ring）to contact with SF6 gas.

6　Adsorbent shall be replaced according to the requirements detailed in the technical documentations of the product.

7　Hoisting appliance，hoisting point and hoisting procedures shall be selected according to the requirements in the technical documentations of the product.

8　All installation bolts must be fastened with torque spanner；moment value shall meet the requirements in the technical documentations of the product.

9　Water-proof glue shall be coated according to the requirements in technical docum-entation of product.

4.2.6　The installation of SF6 tank-type breaker，addition to the requirements of Article 4.2.5 in this Chapter，the following ones shall be met:

1　As for 35kV-110kV tank-type breaker filled with SF6 gas and transported as a whole，SF6 gas may be supplemented directly to the rated pressure when the moisture content is qualified in the field test，otherwise，vacuumizing treatment shall be carried out；as for the breaker transported by parts，it shall be assembled according to the requirements in the technical documentations of the product or those in this Article.

2　The horizontal allowable deviation of tank body on the installation surface shall be 0.59%；the maximum allowable value shall be 10mm；the allowable deviation of interphase center distance shall be 5mm.

3　Internal inspection on site for tank-type breaker with voltage 220kV and above shall be agreed by the manufacturer and carried out under the instruction of manufacturer's technical personnel.Internal inspection shall not only meet the requirements in the technical documentations of the product，but also meet the following requirements:

1）Internal inspection shall be carried out under the weather where the relative humidity of air shall be less than 80%，free from wind，sand，rain and snow，additionally，dust-proof and damp-proof measures shall be adopted.If dust-proof room is required to be constructed in the technical documentations of the product，the to-be-constructed dust-proof room shall meet the requirements in the technical documentations of the product.

2）When free air installation is feasible，free air time shall meet the requirements in the technical documentations of the product.

3）The dressing of internal inspection personnel shall meet the requirements in the technical documentations of the product.

4）Tools，appliance and material for internal inspection shall be registered before applied and counted after completion.

5）Internal inspection shall be carried out with the bushing installation work which shall be carried out according to the requirements in the technical documentations of the product.

6）Internal inspection items include:paint layer of tank body shall be intact，free from foreign matters and spine；shield shall be clean，free from damage and deformation；internal surface of arc extinguish chamber air cylinder and silver coating of conducting rod（electric connecting parts）shall be free from peeling and shedding；connecting positions of conducting rod in the bushing and conducting loop in the tank body shall be correct，and the contact shall be reliable；conducting rod surface shall be smooth，clean and free from burr；bushing internals shall be clean and free from foreign matters；inserted depth of conducting rod shall meet the requirements in the technical documentations of the product.

7）Clean up after internal inspection.

4.2.7　The combined operation for SF6 circuit breaker and its operating device shall not only meet the requirements in the technical documentations of the product，but also meet the following requirements:

1　Before combined operation，the breaker shall be filled with SF6 gas under rated pressure；the first combined operation should be carried out under the instruction of manufacturer's technical personnel.

2　Operation of position indicator shall be correct and reliable，and its positions for disconnection and connection shall meet the actual state of the breaker.

3　With slow switching devices，slow switching operation shall be carried out before rapid switching.

4.2.8　Each operation parameter of breaker after installation and adjustment shall meet the requirements in the technical documentations of the product.

4.2.9　Inspection of equipment current-carrying parts and down lead connection shall meet the following requirements:

1　Flexible connection of equipment current-carrying parts shall be free from damage，surface depression and rust.

2　Contact surface of equipment wiring terminals shall be flat，smooth，clean，and free from oxide film；silver coating parts shall not be grounded.

3　Joint face of equipment wiring terminals shall be coated with a thin layer of electric compounded grease.

4　Connecting bolts shall be complete and fastened；fastening moment shall meet the relevant requirements of the current national standard GB 50149 Electric Equipment Installation Engineering　Code for Construction and Acceptance of Busbar Equipments.

5　Downlead connection shall not make equipment wiring terminal to bear the stress exceeding the allowable bearing stress.

4.2.10　Grading ring shall be free from scratches，burr and deformation with firm，flat and smooth installation.Drainage holes should be punched at the lowest positions of grading ring.

4.2.11　Equipment earthing wire to connect shall meet the requirements of design and the technical documentations of the product，shall be free from rust and damage，with firm connection.