For the high-pressure side of the workshop is 6 ~ 10KV transformer substation main ly2015.2 speaking, there are usually fitted with a time overcurrent protection; such as when an overcurrent protection operation time is greater than 0.5 ~ 0.7s, should also be installed Current Protection. Capacity in the 800KV · A and above oil-immersed transformers and above 400KV · A workshop and oil-immersed transformers should be installed according to the provisions of gas protection (also known as gas relay). Capacity above 400KV · A transformer and, when the number of parallel operation or a single run and standby power as other loads shall be installed in accordance with overload protection possible overload conditions. Overload protection and gas protection during minor faults (commonly known as "light gas"), the action signal, while other protection, including protection in the event of serious fault gas (known as "heavy gas"), generally action on the trip. For the high-pressure side of the plant for more than 35KV substation main transformer and the total down, it also should be installed over-current protection, current protection and gas protection; the possible overload, the overload protection also need to be installed. However, if a single run of transformer capacity in 10000KV · A transformer and above and parallel operation of each capacity when 6300KV · A and above, requires the installation of longitudinal differential protection to replace the current protection. Company Website: http: //www.jilinshengye.com