PURPOSE: To provide an oil-filled electrical device of completely oiltight structure from which insulation oil can be sampled and which can be replenished with insulation oil without dismantling a part of the device.
CONSTITUTION: A piping 11 for sampling oil and a piping 16 for feeding oil are provided inside metal containers 203 and 303 where a device 4 for adjusting the amount of oil in an oil-filled electrical device of completely oiltight structure 15 housed. An oil plug 14 for sampling oil and an oil plug 18 for feeding oil are provided at the outer walls of the metal containers 203 and 303 and the oil plug 14 for sampling oil and the oil plug 18 for feeding oil are connected to a device housing chamber where the electrical device is housed via the piping 11 for sampling oil and the piping 16 for feeding oil. By connecting the oil- sampling pipe and the oil-feeding pipe to the oil plug 14 for sampling oil and the oil plug 18 for feeding oil from the outside respectively, insulation oil is sampled an fed.
MOGI AKIO
OYABU TSUTOMU
