High Voltage Switchgear design criteria? ? GB11022 "high-voltage switchgear General technical conditions" GB1984 "AC high voltage circuit breakers" GB1985 "AC high voltage disconnectors and earthing switches" GB1207 "voltage transformer" GB1208 "current transformer" GB11032 "exchange gapless MOA" GB763 " AC high voltage electrical heating during long-term work "GB2706" AC high voltage electrical dynamic and thermal stability test side cured "GB3309" high voltage switchgear at room temperature mechanical test "GB87354" partial discharge measurement "GB13540" anti-earthquake performance of high-voltage switchgear test "GB311.2-6" high voltage testing techniques "GBl408" Standard Test Method for solid insulating material frequency electrical strength of "GB3906" 3 ~ 35kV AC metal-enclosed switchgear "GB50062" protection of electrical installations and automatic equipment design specifications " SD / T318 "hyperbaric pressure cabinet locking device technology" DL / T539 "exchange of indoor high-voltage and medium voltage cabinet member condensation and contamination test technology" and so on power system to meet the social security and reliability of electricity and supply of how to use low voltage requirements, in substation construction, expansion and transformer capacity increase and other concrete work, the primary consideration is to choose the capacity of the transformer (1) and use the number of units according to power load substation; capacity selection is too large, increasing the transformer itself and related equipment acquisition and installation, operation and maintenance of the investment, resulting in a waste of money; capacity selection is too small, can not meet the power demand, the transformer is overloaded, resulting in equipment damage, the impact of external security and reliable power supply substation; while relatively small number can not meet the wiring mode and power supply reliability requirements, the impact of maintenance and the lack of necessary spare; too many to increase facilities investment, substation layout difficulties, increased repair and maintenance work, the transformer capacity and the number of selected low voltage equipment properly, not only saves construction low voltage switch time investment, but also conducive to the safe and economic operation of the transformer, reduce operating and maintenance costs; In this paper, the relevant regulations transformer maintenance operation of the system, combined with practical experience of working in the field of low voltage Procurement author proposes transformer capacity and Number of units chosen to follow the principles and economic operation conditions and requirements of the different programs economic, technological and security comparative analysis of the factors transformer capacity and the number of units choose to be considered for capacity power supply load and transformers, the number of units to determine the conduct comprehensive safety and efficiency analysis. County low voltage, learning Connaught Electrical and Mechanical, low voltage installation provided by the Henan learning Connaught Electrical and Mechanical Equipment Co., County low voltage, learning Connaught Electrical and Mechanical, low voltage installation Henan learning Connaught Electrical and Mechanical Equipment Co., Ltd. (www.hnxinuo.com) this year introduced a new upgrade, the above picture is for reference only, please call or pictures on this page contact telephone number, to obtain the latest information, contact: Yang Yongjie.