JPH04269410A - Insulating case provided with earthling part between phase - Google Patents

Abstract

PURPOSE:To prevent shortcircuitting failure between phases of an insulating case by imbedding a member having low electric resistance in an insulating material of an insulating barrier between phases of the insulating case to be connected to an outer conductive layer for earthling. CONSTITUTION:Primary side conductors 11 to 13 and secondary side conductors 21 to 23 of R, S, T phases are in parallel fixed to both sides of a three-phase insulating case, while a member having small electric resistance such as a metal plate 5 is imbedded in the barrier 2 between phases between primary side and secondary side conductors 11 and 21 to 13 and 23. This metal plate 5 is earthed by connection of a metal fitting, and even if a crack is generated between phases of the case 1, it is restricted to an earth failure before coming to a shortcircuitting between phases so that the shortcircuitting between phases is prevented so as to limit damage to the minimum.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an insulating case for electrical equipment such as a switch.

0002

[Prior Art] Cases for switching equipment, etc. are generally made of metal materials, but recently, in order to make them smaller and lighter, they are made by embedding three-phase conductors all at once in an insulating material such as epoxy resin. The number of cases is increasing.

[0003] Hereinafter, an insulating case for a switch or the like formed by three-phase one-shot molding will be explained with reference to the drawings. In FIG. 3, an insulating case 1 is formed of a rectangular casing made of an insulating material such as epoxy resin, and the inside thereof is partitioned into three phases by two interphase insulating barriers 2. The primary side conductors 11, 12, 13 of the R phase, S phase, and T phase are on the left side, and the secondary side conductors 21, 22, 23 of the R phase, S phase, and T phase are paired on the right side. The insulated terminals 3 are placed over the terminals, and three-phase switches and the like are inserted and connected.

When such an insulating case is used in high-voltage equipment, it is necessary to install the insulating case along the line BB in FIG.
As shown in FIG. 2, a conductive layer 4 is provided outside the insulating case 1 and is grounded. Furthermore, an interphase insulation barrier 2 or the like is provided between the phases to prevent short circuits between the phases.

[0005]

[Problem to be Solved by the Invention] Incidentally, in such an insulating case that is molded in three phases at once, the interphases are integrally molded with insulating material, but if a crack or the like occurs between the phases, it is difficult to prevent a short circuit between the phases. may occur.

This phase-to-phase short circuit differs from a ground fault in that the resistance at the time of a phase-to-phase short circuit is much lower than that of a ground fault, so a large current flows, the insulation in this area is burnt out, and in some cases, the internal pressure of the insulation case is increased. There is a risk of increasing the temperature and causing a large explosion, and in the worst case, it may even cause a fire.

On the other hand, in the case of a ground fault, the resistance of the ground fault system is quite high, so the ground fault current flowing is small, and the power supply is cut off before the damage is limited to a small area, resulting in minimal damage. many.

[0008] The present invention has been made in view of the above-mentioned points, and the object thereof is to prevent a ground fault from occurring before a short circuit occurs between the phases even if a crack or the like occurs between the phases of the insulating case. .

[0009]

[Means for Solving the Problems] The present invention is characterized in that, in an insulating case in which conductors of multiple phases are embedded and integrally formed, a grounding portion made of a conductive material is simultaneously embedded and formed in an interphase insulating barrier. This is an insulating case with a grounding section between the phases.

0010

[Function] For the interphase insulation barrier of the insulation case, a conductive member such as a metal plate or a material with relatively low resistance such as carbon fiber is embedded and integrally molded into the insulation material that makes up the insulation case, and this is used as an external conductor. By electrically connecting the layers and grounding them, phase-to-phase shorts can be prevented.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 is a plan view of an insulating case such as a switch, and FIG. 2 is a sectional view taken along line A-A in FIG. 1. That is, the three-phase insulating case 1 is formed into a rectangular housing shape using an insulating material such as epoxy resin. On the left and right of this are R phase, S phase, T phase primary side conductors 11, 12, 13 and secondary side conductors 21, 22.
, 23 are fixed in parallel in pairs. A metal plate 5 is embedded in the interphase insulation barrier 2 between the primary conductors 11 and 12 (secondary conductors 21 and 22) and between the primary conductors 12 and 13 (secondary conductors 22 and 23). be done. This metal plate 5 is connected to a connecting fitting 6 as shown in FIG.
Accordingly, the outer conductive layer 4 provided on the outer periphery of the insulating case 1
electrically connected to. Note that the interphase insulation barrier does not necessarily extend from side to side, and may be cut in the middle.

Therefore, in case the conductors 11 and 12, 21 and 22
Even if defects such as cracks occur in the insulator between 12 and 13, 22 and 23, there will be no direct electrical connection (interphase short circuit) with the adjacent conductor, and the embedded metal plate 5 A current flows to ground (not shown) through the external conductive layer 4, thereby preventing short circuit between the phases.

Although the above example describes the case where the metal plate 5 is embedded in the interphase insulation barrier 2, this does not necessarily have to be a metal plate and may be a wire mesh. Alternatively, a metal wire formed into a wave shape may be used. Furthermore, a cloth-like material made of carbon fiber may be used. If there is an electrical margin under normal conditions, these embedded conductive materials may not be completely covered and may be exposed. In this case, the current runs on the surface of the insulator, connects to the exposed grounding part of the metal plate, wire mesh, carbon fiber, etc. before connecting to the conductor of the adjacent phase, and flows to the earth via the ground, and the current flows between the phases. This will prevent short circuits.

[0014]

[Effects of the Invention] As explained above, according to the insulating case in which a grounding portion is provided between the phases of the present invention, a conductive or semiconductive grounding portion is provided in the interphase insulation barrier, thereby preventing short circuits between the phases. This makes it possible to minimize damage.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the configuration of an insulating case according to an embodiment of the present invention;

[Fig. 2] A cross-sectional view taken along line A-A in Fig. 1;

[Fig. 3] A plan view showing the configuration of a conventional three-phase integrally molded insulation case.

FIG. 4 is a sectional view taken along line BB in FIG. 3;

[Explanation of symbols]

1 Insulating case 2 Interphase insulation barrier 3 Insulating terminal 4 External conductive layer 5 Conductive material embedded between the phases 6 Metal fittings 11 to 13 for connecting the external conductive layer and the conductive material embedded between the phases Primary side conductor 21 to 23 Secondary side conductor

Claims (1)

[Claims] [Claim 1] An insulation case in which a grounding part made of a conductive material is simultaneously embedded in an interphase insulation barrier, in an insulating case integrally formed with conductors of multiple phases embedded therein. Case.