US2917677A

US2917677A - Drawout switchgear apparatus

Info

Publication number: US2917677A
Application number: US606039A
Authority: US
Inventors: Myron A Washil
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1956-08-24
Filing date: 1956-08-24
Publication date: 1959-12-15
Anticipated expiration: 1976-12-15
Also published as: JPS336925B1

Description

Dec. 15, 1959 Filed Aug. 24, 1956 5 Sheets-Sheet 1 Fig.|

. W|TNESSES= M INVENWR M Q yron A. OSI

TX BY ATTORNEY 1959 M. A. WASHIL 2,917,677

DRAWOUT SWITCHGEAR APPARATUS Filed Aug. 24, 1956 3 Sheets-Sheet 2 Dec. 15, 1959 M. A. WASHIL DRAWOUT SWITCHGEAR APPARATUS 3 Sheets-Sheet 3 Filed Aug. 24, 1956 United States Patent DRAWOUT SWITCHGEAR APPARATUS Myron A. Washil, Swissvale, Pa., assiguor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 24, 1956, Serial No. 606,039

2 Claims. (Cl. 317-99) My invention relates, generally, to switchgear apparatus and, more particularly, to metal-enclosed switchgear of the drawout type wherein apparatus units are withdrawable horizontally from the housings in which they are enclosed.

In certain applications for switchgear, for example, when it is necessary to provide for connecting a transformer to one or the other of two main power circuits, .drawout fuse assemblies or units may be utilized. The fuses are mounted on trucks or carriages disposed in separate compartments and provision is made for preventing both units from being connected at the same time.

An object of my invention is to provide mechanical interlocking means for two switchgear units of the drawout type which will prevent both units from being connected simultaneously.

Another object of my invention is to prevent access to a switchgear compartment while apparatus within the compartment is energized.

A further object of my invention is to provide for interlocking switchgear apparatus units which are located remotely from each other.

A more general object of my invention is to provide a mechanical interlocking system for switchgear apparatus units of the drawout type which shall be simple and efficient in operation and which may be economically manufactured and installed.

Other objects of my invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of my invention, each one of two compartments which contain disconnect fuses of the drawout type is provided with a compartment door for gaining access to the fuse and an operating door for moving the carriage which supports the fuses. The doors are so hinged that the operating door can be opened independently of the compartment door, but the compartment door cannot be opened without opening the operating door to disconnect the fuses. An interlocking rod is actuated by one operating door to prevent both fuse assemblies from being connected at the same time. Key operated locks interlock the fuse assemblies with a circuit breaker located remotely from the fuse compartments.

For a better understanding of the nature and objects of my invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure l is 'a view, partly in side elevation and partly in section, of a portion of a switchgear structure embodying the principal features of my invention;

Fig. 2 is a view, partly in front elevation and partly in section, taken along the line II-II in Fig. 1;

Fig. 3 is an enlarged view, in front elevation, of a portion of the switchgear structure, the operating doors being in opposite positions from those shown in Figs. 1 and 2;

Fig. 4 is an enlarged view, in left side elevation, of the structure shown in Fig. 3;

ice

Fig. 5 is an enlarged view, in right side elevation, of the structure shown in Fig. 3;

Fig. 6 is an enlarged detail view, in section, of a hinge for one of the operating doors, and

Fig. 7 is an enlarged detail view, in section, of a hinge for one of the compartment doors.

Referring to the drawings, and particularly to Figs. 1 and 2, the portion of a switchgear structure 10 shown therein, is divided into two compartments 11 and 12. The structure 10 may be of the usual construction comprising angle frame members 13 which may be welded together and to which sheet metal plates 14 may be attached to form a metal enclosure for housing switchgear apparatus. The compartment 11 is provided with a compartment door 15 for gaining access to the apparatus within the compartment. Likewise, the compartment 12 is provided with a door 16 for gaining access to the apparatus within the compartment. The compartments 11 and 12 are provided with additional operating doors or carriage moving means 17 and 18, respectively. The operation of the

doors

15, 16, 17 and 18 will be described more fully hereinafter.

As explained hereinbefore, it is frequently desirable to provide for energizing a-transformer or other power translating device from either one of two sources of power. In order to do this, it is necessary to provide switching apparatus for selectively connecting the transformer or other device to one or the other of the two sources of power and also for preventing the transformer from being connected to both sources at the same time.

In the interest of safety, it is also desirable to prevent an operator or other person from coming in contact with electrical apparatus which is energized. In the present structure, current-limiting fuses of the drawout type are utilized as protective devices to protect the translating device against excessive amounts of current and they are so mounted in the housing 10 that only one :set of fuses can be connected at a time. Also, access cannot be gained to either compartment while the fuses within the compartment are energized.

As shown in Figs. 1 and 2, the fuse assembly in compartment 11 comprises a plurality of fuses 21 which are mounted in fuse clips 22 of the usual type. The clips 22 are supported by insulating members 23 which are mounted upon a bracket 24. The bracket 24 is part of a movable truck or carriage 25 supported by rollers 26 which run upon rails 27 attached to a bottom plate 28 of the compartment 11.

One terminal of each fuse 21 is electrically connected to a contact member 31 which is disposed to engage a contact member 32 when the truck 25 has been moved inwardly in the compartment 11. The contact member 32 is supported by an insulating member 33 secured to the back wall 14 of the housing structure 10. As shown, a power conductor 34 may be connected to the contact member 32.

The lower terminal of each fuse 21 is electrically connected to another contact member 31 which engages another contact member 32 mounted on an insulating member 33. A conductor 35 may be connected to the contact member 32. Thus, when the truck 25 is moved inwardly in the compartment 11 to cause all of the contact members 31 to engage their cooperating contact members 32, electrical circuits are established through the fuses 21. The conductors 34 and 35 may be connected to the proper power conductors by connections made externally of the housing 10.

When the truck 25 is in its connected position, the truck frame is grounded through a contact member 36 which engages a contact member 37 connected to the bottom plate 28 of the switchgear structure. When the truck 25 is in its disconnected position, the fuses are grounded through a contact member 38 which engages a contact member 39 attached to one of the angle members 13 of the switchgear structure.

The fuse assembly in compartment 12 is similar to the fuse assembly in compartment '11. The fuse'assernbly in compartment 12 comprises a plurality of fuses 41 which are mounted in fuse clips 42. The clips 4-2 are supported by insulators 43 which are mounted upon a bracket 44. The bracket 44 is part of a truck or carriage 45 supported by rollers 16 which run upon rails 4-7 attached to a bottom plate 48 of the compartment 12.

The terminals of the fuses are connected to contact members 51 which are disposed to engage contact members 52 when the truck 45 is moved inwardly into the compartment 12. The contact members 52 are mounted upon insulators 53 secured to the wall 14 of the housing structure 18.

Power conductors

54 and 55 are connected to the upper and lower terminals 53, respectively. The

conductors

54 and 55 may be connected to external power conductors.

The truck 25 may be moved in the compartment 11 by means of a pair of links 56 which are connected to the truck frame by pins 57. One end of each link 56 is pivotally connected to a bracket 58 by means of a pin 59. The brackets 58 are secured to the carriage moving means or operating door 17. When the door 17 is closed, the brackets 58 extend through openings 61 provided in the compartment door 15.

The truck 45, which is shown in its disconnected position, may be moved in the compartment 12 by means of a pair of links 66 which are attached to the truck frame by pins 67. The outer ends of the links 66 are attached to brackets 68. The brackets 68 are secured to the carriage moving means or operating door 18. Openings 71 are provided in the compartment door 16 for the links 66 and the brackets 68.

As shown most clearly in Fig. 7, the compartment door is hinged to an angle member 72 of the switchgear structure by means of a hinge 73. As shown in Fig. 6, the operating door 17 is hinged to the compartment door 15 by means of a hinge 74 which is attached to a bar 75 secured to the compartment door 15. The hinges 73 and 74 are coaxially disposed. The compartment door 16 and the operating door 18 are mounted in the same manner as the

doors

15 and 17 by means of

hinges

73 and 74.

Since the carriage moving means or operating door for each compartment is mounted on the compartment door for that compartment, the compartment door cannot be opened to gain access to the apparatus in the compartment without opening the operating door. Since the operating door is connected to the truck or carriage in its compartment, access to the apparatus in the com partment cannot be gained without withdrawing the carriage to its disconnected position, thereby deenergizing the fuses and grounding them through the

grounding contacts

38 and 39. Thus, the possibility of any person coming in contact with energized apparatus within either compartment is precluded.

As shown in Fig. 1, the truck in the compartment 11 is in the connected position and the truck 45 in the compartment 12 is in the disconnected position. The truck 25 may be moved to the disconnected position by opening the operating door 17 by means of a handle 70. Thus, both trucks may be in the disconnected position at the same time and the

compartment doors

15 and 16 may be opened to gain access to the fuses inside the compartment.

However, the truck 45 in the compartment 12 cannot be moved to the connected position while the truck 25 in compartment 11 is in the connected position. An interlocking rod 76, which is slidab y mounted in

brackets

77 and 78 attached to a filler plate 79 in the switchgear structure, is disposed to engage a bracket 85 secured to the operating door 17 as seen in Fig. 2. The lower end of the interlocking bar 76 is connected to a pin 82 by means of a link 83. The pin 82 is secured to the operating door 18. Thus, the door 18 is prevented from being closed by the upper end of the interlocking rod 76 engaging the bracket 85 on the door 17. The effective length of the interlocking rod 76 may be adjusted by means of a threaded nipple 84 on the lower end of the rod 76.

If it is desired to move the truck 45 to the connected position, the truck 25 must first be withdrawn to the disconnected position.

As shown in Figs. 3 and 4, the upper end of the interlocking rod 76 is free to pass a bracket 85 secured to the operating door 17 when the door 17 is in the open position. Thus, the operating door 18 may be closed to move the truck 45 to the connected position.

However, the door 17 cannot be closed to move the truck 25 to the connected position while the truck 45 is in the connected position because the bracket 85 will strike the interlocking rod 76 to prevent closing the operating door 17. Therefore, it is necessary to open the door 18 to disconnect the truck 45 and lower the interlocking rod 76 to the position shown in Fig. 1 before the operating door 17 can be closed to move the truck 25 to the connected position.

Accordingly, it is apparent that both sets of fuses cannot be in the connected position at the same time. As previously explained, both sets of fuses can be in the disconnected position at the same time. As also previously explained, it is impossible to open either one of the compartment doors without opening the operating door for the corresponding compartment to disconnect the fuses in that compartment.

As shown in Figs. 3 and 5,

key interlocks

86 and 87 may be provided to prevent the trucks which carry the fuses from being moved to or from the connected position while the disconnecting contact members are energized. A bolt 88 on the lock 86 is in a position to engage a bracket 89 on the operating door 17 to prevent closing the door 17 to move the truck 25 to the connected position. The key for unlocking the lock 86 may be obtained from a circuit breaker (not shown) which controls the energization of the circuit which energizes the fuses 21. This key can be obtained to unlock the lock 86 only when the circuit breaker is open to deenergize the fuses 21.

Likewise, a bolt 91 on the lock 87 is disposed to engage a bracket 92 secured to the operating door 18, thereby preventing the opening of the door 18 to disconnect the fuses 41. The key for unlocking the lock 87 may be obtained from a circuit breaker which controls the energization of the fuses 41 only when the circuit breaker is open. Thus, the

contact members

31 and 51 for the

fuses

21 and 41, respectively, cannot be connected or disconnected while carrying current.

From the foregoing description, it is apparent that I have provided a mechanical interlocking system for preventing two apparatus units of the drawout type from being in the connected position at the same time. However, the interlocking system does not prevent both units from being in the disconnected position at the same time. Furthermore, the possibility of a person coming in contact with either one of the apparatus units while energized is precluded. Also, neither one of the units can be moved to or from the connected position while the disconnecting contact members for the units are energized.

Since numerous changes may be made in the abovedescribed construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all the matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a switchgear structure, in combination, a pair of compartments, disconnect apparatus in each compartment, a movable carriage in each compartment for sup porting the disconnect apparatus, an operating door for each compartment, link means connecting each carriage to the operating door for the compartment containing the carriage, a compartment door for each compartment, the operating door for each compartment being openable Without opening the compartment door for the same compartment, the compartment door for each compartment being unopenable Without opening the operating door for the same compartment, the compartment door for each compartment being closable Without moving the operating door for the same compartment, an interlocking rod slidably mounted on the switchgear structure, and a link continuously connecting said rod to one of said operating doors, said rod being actuated bysaid one operating door to engage the other operating door to prevent both operating doors from being closed at the same time.

2. In a switchgear structure, in combination, a pair of compartments, disconnect apparatus in each compartment, a movable carriage in each compartment for supporting the disconnect apparatus, an operating door for each compartment, link means connecting each carriage to the operating door for the compartment containing the carriage, a compartment door for each compartment,

the operating door for each compartment being openable without opening the compartment door for the same compartment, the compartment door for each compartment being unopenable without opening the operating door for the same compartment, said compartment doors being closable without moving the operating doors, an interlocking rod slidably mounted on the switchgear structure, a link continuously connecting said rod to one of said operating doors, said rod being actuated by said one operating door to engage the other operating door to prevent both operating doors from being closed at the same time, and said rod being disposed to permit both operating doors and both compartment doors to be opened at the same time.

References Cited in the file of this patent UNITED STATES PATENTS 1,575,001 Randall Mar. 2, 1926 1,658,913 Ansingh Feb. 14, 1928 2,156,672 Allen May 2, 1939 2,363,364 Rugg Nov. 21, 1944 2,443,664 Rothfus June 22, 1948 2,504,876 Pringle Apr. 18, 1950 2,573,485 Pifke Oct. 30, 1951 2,689,293 Claybourn Sept. 14, 1954 2,795,739 Wood June 11, 1957