US1863626A - Disconnecting switch - Google Patents

Description

June 21, 1932. F. J. FISCHER 1,863,626

DISCONNECTING SWITCH l Filed Nov. 25, 1929 Patented June 21, 1932 UNITED STATES PATENT OFFICE FRANZ JOSEPH FISCHER, OF DRESDEN, GERMANY, ASSIGNOR T0 THE FIRM KOC STERZEL AKTIENGESELLSCHAFT, 0F DRESDEN, GERMANY DISCONNECTING SWITCH Application led November 25, 1929, Serial No. 409,678, and in Germany November 29, 1928.

My invention relates to disconnecting f l necting switches are sometimes covered with ice. It is an object of my invention to avoid the ice-covering of the switch and in particular of the insulators and the contact members by providing heating resistors within the Contact members or within insulators of the Aswitching device and connected either directly or inductively, to the high voltage line so that long connections and particular heating.

transformers are avoided. The heating resistors may be arranged in the base portion of a rotary insulator.

In disconnecting switches with hollow in' sulators, in the interior of which graded electrical devices such as measuring transformers or grounding inductances are arranged it is a further object of my invention to connect the heating resistor to the low voltage winding of the measuring transformer or the like. In such an arrangement the heating resistor has the same potential as the winding, to which it is connected, and need not be insulated, as are the high `voltage members.

Itis still another object of my invention to provide a shunt resistor of high resistance which is connected in parallel to the heating resistor inserted in a branch line connecting the high voltage line to ground. By this high ohmic resistorovervoltages are transmitted directly from the high voltage line to ground. It is a further object of my invention to provide switching devices in series to the eating resistor so that the resistor may be switched off in summer. In this modification of my invention it is preferable to provide adjustable additional resistors, inductances, capacities or combinations of the same inthe secondary circuits of the measuring transformers to preserve the accuracy and the sensibility of the measuring instruments. In the drawing affixed to this speciiication4 and forming part thereof several devices embodying my invention are illustrated diagrammatically by way of example.

In the drawing:

Fig. 1 is a vertical section of a single break disconnect-ing switch of the rotary type, and

Fig. 2 is a similar section of a double break disconnecting switch of the same type.

Referring now to Fig. 1, 11 is an U-shaped iron member supporting stationary insulators 12, 13 of a rotary disconnecting switch. 14 is a ball and socket joint for the rotary switching blade 15 supported by the insulator 12. 16 is a heating resistor formed as a rod and insulated from the blade 15. 17 is a removable closing member arranged at the end of the blade 15. When the member 17 is removed, the resistor 16 may be put in place in the blade 15. The terminals of the resistor 16 are connected to the closing member 17 and to a contact plug 18 respectively connected to a resistor 19 arranged within the hollow insulator 12. The resistor 19 is connected to ground and by means of the high ohmic resistor 20 to the blade 15, so that the heating resistor is shunted by the high ohmic resistor 20. 21 is a stationary contact member supported by the insulator 13, and engaged by the extension 15 of the blade 15 in the closed position 4of the switch.

The operation of the device is as follows: When the switch is in its closed position, the heat produced in-the resistor 16 is transmitted by conductivity to the ball and socket joint 14, the switching blade 15 and the stationary contact member 21. In consequence thereof these parts are not covered with ice even at low temperatures. Snow falling on the disconnecting blade 15 is melted by the heat produced in the resistor 16 so that mechanical overloads of the disconnecting blades are avoided. In summer the heating resistor 16 may be taken out from the blade 15 after removing the closing member 17.

Referring to Fig. 2, 24 and 26 are the stationary insulators and 25 the rotatable insulator of a high voltage disconnecting switch ofthe rotor type. 22 and 23 are the stationary contacts supported by the stationary insulators 24 land 26, respectively. The movable insulator 25 is supported by means of a ball bearing 27. 28, 29 and 30 are graded voltage and current transformers and a grounding inductance, arranged within the hollow insulators 24, 25 and 26, respectively. 3l is a heating resistor arranged within the stationary contact member 22 and connected to the first primary winding of the voltage transformer 28. 32 is an adjustable resistor shortcircuited by the switch 33, when the heating resistance 3l is inserted. When the heating resistance 3l is removed, the switch 33 Yis opened so that the accuracy and sensibility of the voltmeter 42 is preserved. It an increase of the heating eect is desired, an additional resistor (not shown) of low resistance may be inserted in parallel to the measuring instrument by means of a push button switch (not shown) or the like.

The base portion 34 of the movable insulator 25 is heated by means of the heating resistor 35, the latter being connected to the lowest current transformer 29 by means of a heating winding 36. The heating resistor 35 may be switched oii` by opening the switch 37. Instead of this the heating resistor 35 may be arranged replaceably by means of plug contacts or the like. The heating resistor may be arranged in the stationary supporting portion instead of within the movable base portion, iiexible connections such as the connections 38 of the ammeter 43 or sliding contacts being then provided between the winding 36 and the heating resistor 35. 23 is a stationary contact member supported by the insulator 26 and heated by the heating resistor 39 connected to the terminal of the graded grounding inductance 30. The resistor 39 is shunted by the high ohmic resistor 44 arranged within the head cover 40 of the insulator 26.

4l is the movable disconnecting blade. Heating resistors (not shown) may be arranged within the blade 41. in the manner shown in Fig. l. When it is desired to heat the resistor 35 even when the blade 41 is in its open position, the heating resistor 35 may be connected to a supplementary winding or to taps of any living parts ofthe system (not shown). The insulators and insulating casings are heated by the heat produced in the devices (measuring transformers, grounding inductances or the like) arranged within the hollow insulators. Hereby the effect of the heat-ing resistor is accentuated. The connecting lines are arranged in the interior of the insulators and need not be shielded aga-inst electrical radiation.

I wish it to be understood, that I do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.

In the claims afliXed to this speciiication no selection ot' any particular modiiication of the invention is intended to the exclusion of other modifications thereof and the right to subsequently make claims to any modification not covered by these claims is expressly reserved.

aaeaeae I claim:

l. A. high voltage disconnecting switch comprising a hollow insulator, a live member and a heating resistance both supported by said insulator and thermally connected to each other, one end of said heating resistance being electrically connected to said live member, and an impedance within said insulator having its ends electrically connected to the other end of said heat-ing resistance and to ground respectively.

2. A high voltage disconnecting switch comprising a hollow insulator, a switching member and a heating resistance both supported by said insulator and thermally con nected to each other, one end of said heating resistance bein electrically connected to said switching mem r, and an impedance within said insulator having its ends electrically connected to the other end of said heating resistance and to ground respectively.

3. A high voltage disconnecting switch comprising a hollow insulator, a movable contact member and a heating resistance both supported by said insulator and thermally connected to each other, one end of said heat- .ing resistance being electrically connected to said movable contact member and an impedance within said insulator having its ends electrically connected to the other end of said heating resistance and to ground respectively.

4. A high voltage disconnecting switch comprising a hollow insulator, a hollow dis connecting blade supported by said insulator and a heating resistance formed as a rod and exchangeably arranged within said disconnecting blade, one end of said heating resistance being electrically connected to said disconnecting blade and an impedance within said insulator having its ends electrically connected to the other end of said heating resistance and to ground respectively.

5. A high voltage disconnecting switch comprising a hollow insulator, a hollow disconnecting blade supported by said insulator and a heating resistance formed as a rod and exchangeably arranged within said disconneeting blade, one end of said heating're sistance being electrically connected to said disconnecting blade, a high ohmic resistor connected in parallel to said heating resistance and an impedance within said insulator having its ends electrically connected to the other end of said heating resistance and to ground respectively.

6. A high voltage disconnecting switch comprising a hollow insulator, a live'imember and a heating resistance both supported by said insulator and thermally connected to each other, one end of said heating resistance being electrically connected to said live member, a voltage transformer winding within said insulator having its ends electrically connected to said live member and to ground respectively, and a tap in said transformer said insulator and thermally connected to eachother, one end of said heating resistance being electrically connected to said live member,`aset 'of voltage transformer windings connected in series within said insulator, the ends of said set being electrically connected to said live member and to ground respectively, and a tap in the uppermost of said transformer windings being electrically connected to the other end of said heating resistance.

8. 'A high voltage disconnecting switch comprising a hollow insulator, a live member and a heating resistance both supported by said insulator and thermally connected to each other, one end of said heating resistance being electrically connected to said live member, and a graded impedance within said insulator having its ends electrically connected to the other end of said heating resistance and to ground respectively.

In testimony whereof I affix my signature.

FRANZ JOSEPH FISCHER.

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