Combined box-type substation will become the body of electrical appliances, high voltage switches, fuses, and high and low voltage wires placed in a common closed tank, electrical transformer oil as live parts and ground white insulating medium, is a kind of structure is compact, small, economical power distribution equipment.

Combined box-type substation generally use one of two combinations of energy-efficient modular transformers, transformer core materials are generally of high quality cold-rolled grain-oriented silicon steel or high efficiency amorphous alloy sheet.

ZG (a combination of total box) Combined total box-type transformer oil. The high-voltage transformer load switches, fuses and other electrical protection and control, transformer core is placed in the same tank.

ZF (combination binning) type binning combined oil-immersed transformers. Transformer tank set up two separate sealed units, one unit is mounted high voltage switches, fuses and other electrical control and protection, and the other unit is mounted transformer core.

Transformer body and modular cabinet composed of a box-type substation whole substation transformer cooling surface exposed to the outside of the box, plug-in fully insulated cable head and power connections. Combined box-type substation enclosure features high and low pressure interval. Box positive for high and low voltage operation intervals, within the operating interval of high-voltage terminal, load switch operating handle, no-load tap changer, plug-in fuse, pressure relief valves, oil temperature, oil level gauge and so on. High and low pressure intervals have an interlocking device, when a low pressure interval are not open, they can not turn on the high-pressure space. Plug-in fuse (a protection) and back-up protection fuse in series to form a secondary protection.

Low demand in the interval installing low voltage electrical control wiring scheme (low total and each shunt switch outlet switch, etc.) and manual or automatic reactive power compensation devices and other electrical equipment.

Combined box-type substation needs to be set according to the metering device, the installation of high and low voltage surge arresters, phase controllers, intelligent undervoltage control, condensation control, live display, fault indicator, remote telemetry comprehensive news distribution measurements instrument, such as the protection and monitors.