4 Power Transformers and Oil Immersed Type Reactors

4.1 Loading,Transportation and Erection

4.1.1 In loading and transportation power transformers of 31.5MV·A and above or reactors of 40MVar and above,the transportation route and loading condition shall be investigated fully,and the technical safety measures for construction shall be prepared.The loading and transportation shall meet the following requirements:

1 The following work shall be carried out if water transportation is adopted:

1)When choosing the navigation channel,understanding the depth of channel,distribution of obstacles on and under surface,tide information,and bridges size and bearing capacity on the way.

2)When choosing the ship,understanding carrying capacity and structure of the ship,and checking the stability when loading.

3)Investigating bearing and hoisting capacity of the dock and checking or testing the loading if necessary.

2 If direct mechanical haulage is adopted in road transportation,the loading conditions on the way and at both ends as well as corresponding technical safety measures shall be investigated and prepared seriously.The investigation and technical safety measures shall include the following content:

1)Height,width,gradient,inclination,turning,bearing conditions of bridge,culvert,ditch;and relevant measures needed.

2)Altitude of obstacles(overhead electric power and communication lines,etc),clearance on the way.

3)The vehicle speed of highway transportation shall meet the requirements specified by the manufactory.If the manufactory has no requirements,the speed on high grade road shall not exceed 20km/h;15km/h on grade one road,10km/h on secondary road and 5km/h on other roads.

4.1.2 The loading of the transformer or reactor shall meet the following requirements:

1 The ground of loading platform and dock shall be strongly built.

2 During loading,persons shall be specially assigned for observing the vehicle,and rise and fall of the platform or ship,as to prevent declination exceeding the allowable range.

4.1.3 In loading and transport process,the transformer and reactor shall be free from severe impact and vibration.3-D contact-impact recording instrument shall be arranged for transformers of 220kV and above and capacity of 150MV·A and above,and reactors of 330kV and above.The permissible impact value shall meet the requirements specified by the manufactory and contract.

4.1.4 If machinery is used for pulling transformer and reactor,the pulling point shall be lower than the gravity center of the equipment and meet the requirements specified by the manufactory.The inclined angle shall not exceed 15° during transportation.Special stressed points specified in the product design shall be used in transformer and reactor loading and erection.Skidproof and loosening prevention measures shall be taken.The pulling speed shall not exceed 2m/min.

4.1.5 The steel wire rope shall be attached on the lifting eye special for lifting when bell type tank transformer is lifted integrally.

4.1.6 If the lifting jack is used for lifting large-scale transformer,they shall be placed under the oil tank lifting jack frame.The going up and down operation shall make all points be stressed uniformly.The cushion blocks shall be arranged well in time.

4.1.7 If the transformer and reactor filled with dry gas in transportation,the gas pressure in the oil tank shall be kept at 0.01MPa-0.03MPa,and the dew point of the dry gas must be lower than-40℃.The clean and dry gas storage holder that can supply gas at all times must be arranged as to always keep the positive pressure inside.The pressure shall be monitored by pressure gauges.

4.1.8 Rain and moisture proof measures shall be adopted in the transportation of dry-type transformer.

4.1.9 The body erection shall meet the following requirements:

1 For the transformer and reactor with gas relay,the ascending gradient of 1%-1.5% on the cover along the gas relay airflow direction shall be arranged except those not required by the manufactory.The center line of the bushing shall be consistent with that of the enclosed busbar when connected to the latter.

2 The guide tracks on foundation of the transformer and reactor shall be horizontal,and the track gauge shall be consistent with the wheel one.For the transformer and reactor with wheels,the wheels shall movable smoothly.After erection,the wheels shall be fixed or blocked by dismountable braking devices.

3 If the transformer and reactor body are directly erected on foundation,they shall meet the requirements of the design and the manufactory.