JP2800441B2 - Insulated case with grounding part between phases - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Cases of switchgear and the like are generally made of a metal material in many cases, but recently, in order to reduce the size and weight of the case, three-phase conductors are collectively embedded with an insulating material such as epoxy resin. Cases have also increased.

Hereinafter, an insulating case such as a switch formed by three-phase molding will be described with reference to the drawings. In FIG. 3, an insulating case 1 is formed of an insulating material such as an epoxy resin in a rectangular casing, and the interior is partitioned into three phases by two inter-phase insulating barriers 2. And on the left, R phase, S phase,
The T-phase primary-side conductors 11, 12, and 13 have the R-phase,
The S-phase and T-phase secondary conductors 21, 22, 23 are arranged so as to form a pair, respectively, and these primary conductors 11, 1
2, 13 and the secondary-side conductors 21, 22, 23 are mounted with insulating terminals 3 placed thereon, and three-phase switches, not shown, are inserted into spaces in the housing separated by the inter-phase insulating barrier 2, respectively. It is connected and installed outdoors.

When the insulating case 1 formed as described above is used for high-voltage equipment, even if a person touches the insulating case 1, electric shock such as electric shock is prevented.
As shown in FIG. 4 along the line, a conductive layer 4 is provided outside the insulating case 1 and is grounded. In addition, an interphase insulating barrier 2 made of an insulator is provided between the phases,
A short circuit between each phase is prevented.

[0005]

In the case of such an insulating case molded in a three-phase package, the interphase is integrally molded with an insulating material. However, if a crack or the like occurs in the interphase insulating barrier 2, An interphase short circuit may occur.

[0006] This phase-to-phase short-circuit is different from the ground-to-ground fault, in that the resistance during the phase-to-phase short-circuit is considerably smaller than the resistance to the ground-to-ground fault. Could cause a large explosion, raising the worst case and causing a fire.

[0007] On the other hand, in the case of a ground fault, the resistance of the ground fault system is considerably high, so that the flowing ground fault current is small, and the power supply is cut off within the degree of the damage to a part, and the damage may be reduced. Many.

The present invention has been made in view of such a point, and even if a crack or the like occurs in the inter-phase insulating barrier of the insulating case, the inter-phase fault is intended to be limited to a ground fault before the inter-phase short circuit occurs. It is an object of the present invention to provide an insulating case provided with a grounding portion.

[0009]

According to the present invention, in an insulating case formed by embedding conductors of a plurality of phases, an interphase insulating barrier formed of an insulator provided so as to partition between conductors of each phase is made of a conductive material. An insulating case provided with a grounding portion between phases, wherein the grounding member and a connection fitting for connecting the grounding member and an external conductive layer provided outside the insulating case are embedded and integrally formed. It is.

[0010]

A conductive member such as a metal plate or a material having a relatively low resistance such as carbon fiber is embedded in an insulating material constituting the insulating case and integrally molded into the interphase insulating barrier of the insulating case. By electrically connecting to an external conductive layer provided outside the case with a connection fitting and grounding it, a short circuit between phases can be reliably prevented.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of an insulating case such as a switch, and FIG. 2 is a cross-sectional view taken along line AA of FIG. That is, the three-phase insulating case 1 is formed in a rectangular casing with an insulating material such as an epoxy resin. On the left and right sides, R-phase, S-phase, and T-phase primary conductors 11, 12, 13 and secondary conductors 21, 12,
2 and 23 are fixed so as to form a parallel pair. A metal plate 5 is embedded in the interphase insulating barrier 2 between the primary conductors 11 and 12 (secondary conductors 21 and 22) and the primary conductors 12 and 13 (secondary conductors 22 and 23). Is done. The metal plate 5 embedded in the inter-phase insulating barrier 2 is
As shown in FIG. 2, both sides are electrically connected to the external conductive layer 4 provided on the outer periphery of the insulating case 1 by the connection fittings 6. Note that the interphase insulating barrier 2 does not necessarily have to be connected to the left and right housings, and may be cut off halfway.

Therefore, the conductors 11 and 12, 21 and 22
Even if a defect such as a crack occurs in the inter-phase insulating barrier 2 which is an insulator between the sub-layers 12 and 13, 22 and 23, the inter-phase insulating barrier 2 is not electrically connected directly to the adjacent conductor (inter-phase short circuit). A current is connected to the metal plate 5 embedded in the insulating barrier 2 and flows through the external conductive layer 4 to the ground (not shown) via the external conductive layer 4, so that a short circuit between the phases can be reliably prevented.

In the above example, the case where the metal plate 5 is embedded in the interphase insulating barrier 2 has been described. However, this is not necessarily a metal plate but may be a wire mesh. Further, the metal wire may be formed into a corrugated shape. Further, a cloth-like material made of carbon fiber may be used. If there is an electrical margin in a normal state, these buried conductors may be exposed without completely covering the surroundings. In this case, the current runs on the surface of the insulator, and is connected to the external conductive layer 4 through the grounding metal 6 from the grounding member such as a metal plate, a wire mesh, and carbon fiber which are exposed before being connected to the conductor of the next phase. Current will flow to ground via ground, which will reliably prevent shorts between phases.

[0014]

As described above, according to the insulating case of the present invention in which the ground portion is provided between the phases, since the interphase insulating barrier is provided with the conductive or semiconductive ground portion, for example, cracks may occur. However, short-circuiting between phases can be reliably prevented, and damage can be minimized. In addition, since the switch and the like are covered with an air-tight insulating case, the insulating case is small and light in weight, easy to manufacture, suitable for mass production, easy to install, and extremely safe.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a plan view showing a configuration of a conventional three-phase batch-molded insulating case;

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulation case 2 Insulation barrier between phases 3 Insulation terminal 4 External conductive layer 5 Conductive material embedded between phases 6 Metal fitting for connecting external conductive layer and conductive material embedded between phases 11-13 Primary conductor 21-23 Secondary side conductor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Michihiro Nemoto Inventor 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture “Inside the Hidaka Works of Hitachi Cable Corporation” (56) References JP, U) Actually open sho 59-103328 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01H 9/02 H01H 9/12 H01H 31/02 H01H 33/02

Claims (1)

(57) [Claims] 1. An insulating case formed by embedding conductors of a plurality of phases so as to be divided between conductors of each phase.
Ground made of conductive material on interphase insulation barrier formed of insulator
Member, an external member provided outside the grounding member and the insulating case
Embedded with connection fittings for connecting conductive layers and integrally molded
Insulating case having a ground portion that is to form during the phase characterized by.