SLIDING DOOR FOR SWITCHGEAR AND CONTROL CUBICLES

Abstract: A vertically sliding door (5) for switchgear and control cubicles, wherein the door is housed in the front side of the switchgear and control cubicles and designed to slide on guides (6) mounted in the height sides of the switchgear and control cubicles.

Description: Sliding door for switchgear and control cubicles TECHNICAL FIELD Switchgear and control cubicles are included in most elec¬ tricity supply and industrial plants. The extent and the contents of the switchgear and the control cubicles depend on the application in question. In its simplest design, a switchgear installation may comprise a few single cubicles with an incoming circuit breaker and a few outgoing switch diverter cubicles for distribution of electric power to the different consumers. Large industrial plants such as rolling mills, paper machines, nuclear power plants, etc., however, require more complicated and extensive switchgear and con- trol cubicles. In this case, there is a need of disconnec¬ ting cubicles, switch diverters, measurement cubicles, circuit-breaker cubicles, contactor cubicles, cubicles for relay protection, control and controlling equipment, etc. This means that, at least for large industrial plants, the space requirement for these switchgear installations and control cubicles may become extensive. Not infrequently, the operating members, monitors, etc., of the plant are also housed in the same room, referred to below as the control room. The present invention relates to a special embodiment of the doors of the switchgear and control cubicles, which permit the space requirement of the control room, independ¬ ently of whether it comprises switchgear and control cubicles only or whether it also comprises control panels panels, etc., to be considerably reduced. BACKGROUND ART, THE PROBLEMS To place the invention in its proper context, a short description of different types of cubicles and the standards determining the design thereof will first be given. The switchgear and control cubicles referred to here comprise both low-voltage and high-voltage designs, that is, generally up to 36 kV in indoor version. According to SS-IEC 298, metal-enclosed indoor switchgear installations, for example, are divided into three main groups: metal-clad, compartmented, and cubicle-enclosed switchgear. In the metal-clad switchgear, the components are placed in compartments with partitions of metal. In the compartmented switchgear, all the components are placed in separate compartments where one or more of the partitions are of a non-metallic material. A typical com¬ partmented switchgear installation is shown, inter alia, in ABB pamphlet SB 84-201 E, Edition 2 1994-01. In the cubicle-enclosed switchgear, both breakers and cables, for example, are housed within the same space. The personal safety is therefore much inferior to that afforded by the metal-clad and the compartmented switchgear installa¬ tions. The classical design when it comes to doors for these switchgear installations and control cubicles is that the doors are provided with hinges to be able to open the cubicles and have access to the different built-in components. One common design is for the door to cover the entire open front side of the switchgear or the control cubicle. This largely means that the height of the door corresponds to the height of the switchgear or the control cubicle and that the width of the door corresponds to the width of the switchgear or the control cubicle. The hinges may then be attached to the righthand or lefthand height side of the door depending on whether a right hung or a left hung door is desired. When the door is opened and turned outwards 90 degrees, the free height side of the door will thus be at a distance from the cubicle which largely corresponds to the width of the switchgear or the control cubicle. An important factor in this connection is that, normally, a switchgear or control cubicle door has a width of 600 or 1000 mm. In connection with the introduction of the switchgear and control cubicles which are divided into compartments, a different design with hinged door has become commonly used. The division into compartments permits the front of the switchgear or the control cubicle m the height direction to be divided into a plurality of part doors. The hinges can be attached, as mentioned above, to the righthand or lefthand height side of the part doors. When the part door has turned outwards 90 degrees, also with this design the free height side of the part door will be at the same distance from the switchgear and the control cubicle as described above. The switchgear or control cubicles divided into compartments permit a further way to have access to the components for supervision, service, etc. This is clear, among other things, from the above-mentioned ABB pamphlet. Here the part doors are provided with hinges either on the underside or the upper side of the part doors, which means that they can be folded outwards-downwards or outwards-upwards. When the part doors have turned outwards 90 degrees, their free, out¬ wardly-facing side will be at a distance from the switchgear or the control cubicle which corresponds to the height of the part doors. This entails a certain freedom to choose or influence the distance from the switchgear or the control cubicle to the free outwardly-facing side of the part doors. If an accident should occur when working inside a switchgear installation or a control cubicle, that is, when one or more doors are open, it is very important that the evacuation routes in case of emergency evacuation past the opened doors are sufficiently large. This means that the space requ re- ment of the switchgear and control room with respect to operation aisles etc. with openable doors according to the state of the art is considerably larger than if the ouilt-m components of the switchgear and control cubicle were available without these outwardly-facing door. This larger space requirement has an adverse affect on the cost cf the total building. In the comprehensive international standard IEC 1330, First Edition 1995-11, H αh-voltaσe/low-volt-.aσe nrefabrmated substations, the following provisions regarding the space in front of switchgear and control cubicles are given under section 5.5.8: "5.5.8 Operation aisle The width of an operation aisle inside a prefabricated sub¬ station should be adequate for performing any operation or maintenance. The width of such an aisle shall be 800 mm or greater. Doors of switchgear and controlgear inside the prefabricated substation shall either close in the direction of exit or rotate such that they shall no reduce the width of the aisle. Doors in any open fixed position or mechanical drives protruding from the switchgear and controlgear shall not reduce the width of the aisle to less than 500 mm. " The significance of this in view of the cubicle width mentioned above is that the free passage in case of closed doors must be 600 + 500 = 1100 mm and 1000 + 500 = 1500 mm, respectively. In this connection it should be mentioned that there is a Swedish standard SS 436 21 01 Stallverksrum l bvσσnader ("Switchgear room in buildings), which refers to Starkstromsforeskrifterna betraffande manόverαanα ("The heavy-current directions relating to operation aisle") . Paragraph B86 b of these directions states: The aisle width in front of a single switchgear installation shall be 1.5 m, between two medium-voltage switchgear installations 1.8 m. Open doors may restrict the evacuation route down to 0.5 m. In the light of these directions, the space savings are of the same order of magnitude as those described above. In connection with commissioning of a plant, service and maintenance, there is usually a need to work in parallel in and with several of the switchgear installations and/or the control cubicles at the same time. With open and outward doors according to the prior art, it is complicated to move from one switchgear installation or control cubicle to another while at the same time it becomes more difficult to supervise whether breakers, contactors, etc., are open or closed. When the doors are open and block the way, there is always a risk that the person performing the commissioning work moves from one cubicle to another in the wrong direc- tion and that he performs the wrong connection in the wrong cubicle. In addition, there is always a risk of hurting oneself and getting caught in a door when there is a hurry, which is normally the case when commissioning. SUMMARY OF THE INVENTION, ADVANTAGES The invention comprises replacing a door which, according to the state of the art, swings outwards into the operation aisle with a door which is slidable in the vertical direc- tion. This can be done by allowing the door to slide on side guides mounted in the cubicle. This means that an operation aisle, in order to keep the standardized width, does not have to be wider than 800 mm. This means that, with the cubicle widths mentioned above, an operation aisle can be made 300 and 700 mm narrower, respec¬ tively, than an operation aisle with doors swinging out¬ wards, that is, a significantly reduced space requirement can be obtained. Further, such a door construction means that the above- mentioned disadvantages of doors swinging outwards are eli¬ minated while at the same time the time for commissioning, service and maintenance of several adjacently located switchgear installations and control cubicles can be con¬ siderably reduced. In addition, the safety will increase because of the improved overview provided thereby. DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will now be described with reference to the accompanying drawing which shows an enclosure for a switch- gear unit or a control cubicle. The enclosure comprises a front and a rear part. The enclosure largely corresponds to the switchgear and control cubicles which are described in the above-mentioned ABB pamphlet. In the embodiment shown, the rear part comprises a lower space 1 for incoming/outgoing power cables. This space is separated from the upper part 2 by a horizontal compartment wall 3. The upper part 2 in the embodiment shown is conceived to comprise a circuit-breaker (not shown) mounted on the com¬ partment wall 3 towards the front part 4. The upper space may furthermore comprise a busbar system, measurement devices, etc. According to the invention, the front part 4 comprises the door construction 5 which in the figure is shown in a drawn- down position. In a preferred embodiment, the door has a height smaller than or equal to half the height of the switchgear or the control cubicle. At the lower part, the front part of the switchgear or control cubicle comprises a U-bent plate (not shown) which covers the front side of the lower rear space 1. The front plane side of the U-bent plate is intended to lie immediately behind the door 5 in the drawn-down position. The centremost part of the front part comprises the door 5 which is slidable upwards and downwards by means of guides 6. By integrating the handle of the door into the door construction, there are no protruding parts which may obstruct evacuation in an emergency. In the door construction shown, the door is provided with a recessed mid-section 7, the lower 8 and upper 9 edges of which are used for pushing the door downwards/upwards. In the upper part 10 of the front part, space is provided for relay protection equipment and other control equipment. This space is protected by an upper door 11 which preferably may be provided with hinges at the upper part, whereby this door can be folded outwards/upwards. Other and similar designs of the upwardly and downwardly sliding door construction are within the scope of the invention. Thus, for example, those parts of the guides against which the door slides, or those edges of the door which are facing these, possibly both the guides and the door, may be provided with a suitable sliding-facilitating material of plastic or the like to reduce the friction between the edge of the door and the guides.

Claims: CLAIMS 1. A vertically sliding door (5) for switchgear and control cubicles, characterized m that the sliding door is housed in the front side of the switchgear and control cubicles and that it is adapted to slide on guides (6) mounted on the height sides of the switchgear or control cubicles. 2. A vertically sliding door (5) for switchgear and control cubicles according to claim 1, characterized in that the sliding door has a height which is smaller than or equal to half the height of the switchgear or control cubicle. 3. A vertically sliding door (5) for switchgear and control cubicles according to claim 1, characterized in that the sliding door is provided with a device (7) to facilitate the displacement of the door in the vertical direction. 4. A vertically sliding door (5) for switchgear and control cubicles according to claims 1 and 3, characterized in that the device (7) to facilitate the displacement of the door in the vertical direction is designed as a mid-section (7) recessed in the door with a lower (8) and an upper (9) edge. 5. A vertically sliding door (5) for switchgear and control cubicles according to claim 1, characterized in that those height edges of the sliding door which are facing the guides are provided with a sliding-facilitating material. 6. A vertically sliding door (5) for switchgear and control cubicles according to claim 1, characterized in that the guides which are mounted in the height sides of the switch- gear and control cubicles, and in which the vertically sliding door slides, are provided with a slidmg-faciiita- ting material. 7. A vertically sliding door (5) for switchgear and control cubicles according to claims 1, 5 and 6, characterized in that both those height edges of the sliding door which are facing the guides and those guides which are mounted on the height sides of the control cubicles are provided with a sliding-facilitating material.

Inventors: FROEBERG HAAKAN, FROEBERG, HAAKAN
Applicants: ASEA BROWN BOVERI, FROEBERG HAAKAN, ASEA BROWN BOVERI AB, FROEBERG, HAAKAN
Application year: 1997
Main classification: H02B1
IPC codes: H02B1, H02B13