JPH0124923Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a feed-through current transformer, and particularly relates to an improvement in the moisture-proof and waterproof structure of a low-voltage coil.

The structure of a conventional feedthrough current transformer will be explained with reference to FIG. In a conventional feedthrough current transformer, for example, an insulator 3 is placed around a belt-shaped annular core 1 wound in a circle.
Further, a plurality of low voltage coils 2 are wound around the entire circumference of the iron core 1 so as to form a plurality of layers. An insulator 3 is applied between each layer of the low-voltage coil 2, and after the winding of the low-voltage coil 2 is completed, an insulator 3 is also applied to the outermost periphery. A conductor such as a bus bar (not shown) passes through the window of the annular core 1.
A through-type current transformer configured in this way will prevent moisture from entering the current transformer even if rainwater or the like falls on it for a short period of time for some reason after it is installed in a generator, shield breaker, etc. In order to prevent the dielectric strength of the insulator 3 of the low-voltage coil 2 from decreasing, for example, a porous tape is wound to an appropriate thickness so as to cover the entire outermost insulator 3. The tape part was impregnated with varnish to form a varnish layer 4 to obtain waterproof properties. According to this structure, special equipment is required for impregnating the varnish to form the varnish layer 4, and a drying space is required for drying after impregnating the varnish, resulting in economic, equipment, and workmanship problems. There was a disadvantage.

The purpose of the present invention is to obtain a through-type current transformer that can be easily constructed without requiring special equipment space, and has highly reliable moisture-proof and waterproof properties.

The present invention will be explained below with reference to an embodiment shown in FIG.

The same parts as in FIG. 1 are indicated by the same reference numerals. As shown in FIG. 2, it is composed of an annular iron core 1, a low voltage coil 2 wound around the annular iron core 1 in a plurality of layers, and an insulator 3 applied between the layers of the low voltage coil 2 and on the outermost periphery. A waterproof or moisture-proof self-adhesive insulating tape 5 is wound to an appropriate thickness around the outermost insulator 3 so as to cover the entire current transformer element. This self-adhesive insulating tape 5 forms a waterproof or moisture-proof layer by simply winding it at room temperature due to the surface pressure applied during winding. Alternatively, the self-fusing insulating tape 5 may be wound and then heated at an appropriate temperature to further increase the fusing properties of the tape.
By forming a waterproof or moisture-proof layer using the self-adhesive insulating tape 5 that covers the entire current transformer, water or moisture can be prevented from entering the inside of the current transformer.
A decrease in the dielectric strength of the insulator 3 can be prevented.

As described above, according to the present invention, a self-bonding insulating tape is wound to cover the insulation applied to the outer periphery of the low-voltage coil wound around the iron core, so special equipment and space are not required. You can easily work without having to
A highly reliable feed-through current transformer with waterproof properties can be obtained.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway sectional view of a conventional current transformer;
The figure is a partially cutaway sectional view of a current transformer showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Annular iron core, 2... Low voltage coil, 3... Insulator, 4... Varnish layer, 5... Self-fusing insulating tape.

Claims (1)

[Scope of utility model registration request] An annular core, a low-voltage coil wound around the annular core, an insulator that insulates the area between the annular core and the low-voltage coil, and the low-voltage coil from the outside, and a waterproof material wrapped around the entire circumference of the insulator. , a feed-through current transformer consisting of a moisture-proof self-adhesive insulating tape.