Patent Application
20180219359
The following is related to a device notably developed to promote more security and better efficiency in its use, i.e., to operate in the locking and actuation of electrical connectors positioned in extractable drawers for MCC cabinets, thereby setting a safety device capable of connecting or disconnecting the internal connectors, both main and test connectors, provided in the extractable drawer for MCC cabinet, said procedure is executed mechanically through an assembly of elements that interconnect two thin laminar plates, these in turn, interconnected to each other, positioned inferiorly to the body of the drawer and with conformations corresponding to promote a perfect fit.
The safety device for locking and actuation of electrical connectors arranged in extractable drawer for a MCC cabinet, is particularly belonging to the field of safety devices for the actuation and/or locking of electrical equipment, said device of external operation with the door closed, promotes protection to operators of extractable drawers in MCC cabinets.
As known by the professionals of the industry and commerce of electrical equipment, particularly electrical cabinets of MCCtype (Motor Control Center), the referred MCC cabinets configure a handling and loading control system, especially of electrical motors of low or middle voltage.
The MCC cabinets are currently divided into areas that accommodate equipment for protection, sectioning and handling of loads, which present important function in the distribution systems of electric power in commercial and industrial units. Exactly where the cables from the loads are connected.
Although most of the industrial loads are formed by motors, reason of the name MCC (Motor Control Center), the term “loads” is quite general and can mean any equipment that consumes electrical energy, such as greenhouses, resistors and other correlated equipment, being its use intended to industrial installations presenting a plurality of loads that must be commanded, in which a maximum continuity of operation must be assured, and where the access of unskilled personnel is necessary, or also, in which is required a high level of safety for operators and maintenance personnel.
The MCC cabinets are made of metallic material, self-sustained, simplified or armored, which may be of TTA-type (Totally Tested Assembly), or PTTA-type (Partially Totally Tested Assembly).
In the TTA concept, the performance is assured by tests carried out individually in the plurality of components (bus, inputs, outputs, feeders, motor starters, etc.) or in the complete assembly.
These tests have the purpose of ensuring the performance of the assembly and minimize the risks caused by errors of the projects.
On the other hand, in PTTA-type, only some components are assayed and tested.
Therefore, the referred cabinets are formed by drawers which can be fixed or extractable.
The extractable drawers are specific for a safer operation and faster maintenance, mostly in cases of replacements during the operation.
The MCC cabinets are designed with a high standardization index, facilitating the assembly, installation and maintenance, besides allowing expansions and interchangeability between drawers of the same MCC cabinet model and of the same dimensions and functions.
The MCC cabinets have functions of mechanical and electrical interlocking, protection against the touch of living parts, total interlocking of contactors, metal divisions which prevent arc propagation, besides of providing safety of personal, operation and maintenance.
At the beginning, the MCC cabinets were not compartmentalized, i.e., they were provided with a single mounting plate, where the protection and the handling assemblies of individual loads were mounted together in this same plate; this solution is known as a conventional electrical cabinet.
On the other hand, in the compartmentalized MCC cabinets, the safety and handling equipment of each individual load are mounted in isolated compartments inside of the same panel. This MCC cabinet can be fixed or extractable.
In the fixed MCC cabinet, particularly inside each compartment is mounted a fixed mounting plate, where the equipment for safety and handling of the start are positioned.
Meanwhile, in the extractable MCC cabinet, particularly inside each compartment is mounted a drawer, which can be removed from the panel without the assistance of tools, such as levers or cranks, a common means of extraction for a long period of time.
The equipment for safety and handling of the starts are mounted inside the drawers, minimizing the downtime, since in this way, is possible to quickly replace the drawers.
The MCC cabinets are essential assemblies for the production, and with the advancement of technology and the need for the monitoring and the controlling of production, the use of networks is a solution that enables to reduce the downtime from hours to minutes, with a better and more complete diagnostics, by means of supervisory systems which locate accurately the problematic points during the production process, making it possible to know in what and where intervene and correct.
The prior art provides some models of extractable drawers for MCC cabinets, wherein each one is provided with a means other than extraction and reinsertion in the MCC cabinet, in addition to provide a handling, locking and actuation means of the electrical connectors.
After a brief search in the world patent banks, several documents of important relevance were found, among which the PI 0700143-6 filed on Apr. 1, 2007, under the title, “SLIDING CONNECTION DEVICE OF EXTRACTABLE DRAWER IN ELECTRICAL PANEL”, which refers to a sliding connection device for connecting a extractable drawer to a bus bar of main power of an electrical panel, comprising a section fixed to the drawer and a sliding section associated to said fixed section. The fixed section is provided with terminals to which the power cables are connected and the sliding section is provided with electrical contacts for connecting to the power bus bar, and that between said fixed section and said sliding section is arranged at least one movement course in the form of a groove and at least one intermediate contact performing the physical and electrical connection between said sections.
Thus, the device is capable of moving itself for coupling or uncoupling to the power bus bar in such a way that only the sliding section performs this movement, while the fixed section and the power cables associated to it, remain immovable.
Further documents are described below, namely, DE102008046881, DE19504474 and FR2126117.
The document DE102008046881, filed on 18 Mar. 2010, provides a module that has a locking unit and a contact switch unit with multiple contact switches, where the contact switches are operated by the locking unit, and where the locking unit and the contact switches are arranged in upper housings or on a housing carrier.
Two actuation components in the form of key holders are provided in the locking unit, being the module movable between a separating position and an operating position by the actuation components.
The contact switches are in contact with the bus bars in the operating position.
The second document, DE19509474, filed on 19 Sep. 1996, discloses a switching device that provides a number of shelves for holding bus bars coupled to the drawers, wherein for each bus bar there are contact sliders, and each of these has a rigid contact rail.
There is still a mechanism to bring the rack into contact or withdraw it, and the contact sliders and rails are on the back side of the rack.
All the contacts of one rack are operated by the same mechanism, positioned on the front side of the rack.
The contact sliders have grooves perpendiculars to the sliding direction in which a comb-like coupling element is positioned, joining to the operating mechanism and, finally, each contact slider has two spring contacts, between which the bus bar fits.
The third document, FR2126117, filed on 26 Feb. 1971, relates to the embodiment of a mechanical coupling system for a locking position of two objects, and afterwards its release or disengagement, being this effect possible due to the use of two appropriate levers, where its commands can be simultaneous or not, and may be even used in junction of connectors, drawers, cabinets, power modules, etc.
The prior art further discloses the document AU2002252966, filed on 17 Feb. 2005, which refers to a low voltage switchgear comprising an appliance module for receiving appliances according to the switching, control and protection technology. A locking bar comprising laterally projecting bolts is arranged in a housing of the appliance module, perpendicularly in relation to the direction of displacement.
Positioning cranks are arranged on lateral edges of the bottom of a section, the bolts co-operating with said positioning cranks in order to lock the appliance module in an operating, separating and test position.
A lifting gear is used to lift the locking rod in its working position, said lifting gear being actuated by means of a control unit which is arranged on an operating face.
The test position is held if a separation auxiliary contact is locked in the separation position of the appliance module.
Another document is U.S. Pat. No. 7,791,862, filed on 19 Jun. 2008 and refers to an electrical switching system comprising a housing and components which are arranged therein and which are embodied as a control and/or measuring unit.
Said components are arranged in modular-type drawers.
A base module comprises at least one module support profile, in addition to lateral walls and front sided insertion elements.
One front wall of the base module, preferably the front side thereof, is formed by a control unit and the opposite front wall of the measuring unit, and the dimensions of the control and measuring unit are adapted to the size of the module.
Nevertheless, the most modern and used type of extractable drawer in the prior art is still to be mentioned herein, and is configured by a type of extractable drawer equipped with a safety system which has two actuation and locking keys of the assemblies, being one smaller that actuate the connectors of the test command and one larger that actuate the connectors to the power input of the system, i.e., coupling the connectors to the bus bars, which actuates all the equipment connected therein.
First, it is worth mentioning that in this type of extractable drawer, the procedure that the operator uses to verify the functioning conditions of the system takes place from the actuation or rotation of the lower command, which is conformed by a special short key, that mechanically actuate the test device of the system.
After verifying the conditions of the equipment that will be actuated, when the operator rotates the special short key in reverse, the test device of the system will be de-energized.
Thus, after withdrawing the special short key, an elongated key is inserted in the same hole, actuating also by rotation, the equipment, being this actuation executed through a mechanical device provided with a plurality of rods, turnstiles and joints, which interconnects the actuating means of the equipment, pressing the clutches of the extractable drawer, connecting them to the bus bars that energize the equipment.
The device described above is what there is of most modern used by the consumer public. However, the referred device also presents some inconvenience among which the need of using two keys for the actuation of the test and operation of the equipment.
Another important inconvenient is due to the number of components used for the full operation of the device, where the fatigue or failure of any of the component elements of this device, may cause the malfunction or still the total locking of the aforementioned safety device.
An aspect relates to a safety device for the locking and actuation of electrical connectors provided in extractable drawer for mcc cabinet, which should be positioned with total distinction among its similar and be customized before the consumer market by the fact of presenting a device developed to promote more safety in its use, i.e., to actuate in the locking and actuation of electrical connectors positioned in the extractable drawers for MCC cabinets, thereby setting a safety device capable of connecting or disconnecting the internal connectors along with their respective bus bars, both the main connector and the test connector, arranged in an extractable drawer for MCC cabinet, said procedure is executed mechanically through an assembly of elements that interconnects two thin laminar plates, these in turn are interconnected to each other, positioned inferiorly and of conformations corresponding to promote a perfect fit. The mechanical actuation of the elements of this assembly is performed externally with the door closed, from the actuation of a main key which actuates a pendulum, which moves an assembly of gears suitably arranged in the extractable drawer for MCC cabinet, which in turn moves the lower laminar plates, connecting the test device and posteriorly the connectors, wherein said connectors, when in contact with their corresponding bus bars, energize the equipment in which they are connected.
Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:
In accordance with the aforementioned illustrated figures, the following refers more particularly to a safety device 1 notably developed to promote the connection and disconnection of the internal connectors with the corresponding bus bars 12, both the main power connector that actuates the main equipment and the test connector are arranged in the extractable drawer 4 for MCC cabinet 16 of multiple compartments 17, with mechanical movement of the elements provided in the safety device 1, which takes place externally with the door closed, from the movement of a special actuation key 2 that is provided with an autonomous safety device which in turn actuates a pendulum, that moves the gear assembly 6 suitably arranged on the front section of the extractable drawer 4 for MCC cabinet 16, immediately behind the safety device 1, wherein said safety device 1 actuates the gear assembly 6, which in turn move the lower laminar plates 5 and 5A actuating the test connector and subsequently the main connectors, being that the main connectors, when in contact with their corresponding bus bars 12, energize the equipment in which they are connected.
The laminar plates 5 and 5A are strategically positioned on the lower face of the extractable drawer 4 for MCC cabinet 16 and are provided with a plurality of small oblong cutouts 18 wherein small guide pins 19 are fitted and arranged in the base 20 of the extractable drawer 4, which is formed in a single piece, said guide pins 19 delimit the movement of these plates 5 and 5A.
Furthermore, said plates 5 and 5A are provided with at least two small laminar tabs 14, which are orthogonal extensions of the plates 5 and 5A themselves, being these orthogonal to its plane and inserted in guide cutouts 21, pressing the connectors provided on the extractable drawer 4 towards their corresponding bus bars 12.
The laminar plates 5 and 5A are provided with also a plurality of small rectangular cutouts 22 aligned with each other and passible of receiving the gear teeth provided in the gear assembly 6, by moving the laminar plates 5 and 5A to connect or disconnect the connectors of the bus bars 12.
As stated above, the procedure is performed mechanically through at least one gear assembly 6 which interconnect the safety device 1 with the thin and inferior laminar plates 5 and 5A, these in turn are interconnected to each other, being positioned inferiorly and of corresponding conformations, the larger laminar plate 5 moves the connectors toward the corresponding bus bars 12, energizing therefore the entire system and, in addition, a smaller laminar plate 5A is provided corresponding to the first larger laminar plate 5, being said laminar plate 5A actuated before the larger laminar plate 5, so that a functioning test is performed in order to release the operation of the main equipment for use.
The test device is actuated on the first movement of the actuation key 2 of the extractable drawer 4, concomitant with pressing the locking device 3, without which the actuation key 2 does not rotates, connecting the test device of said extractable drawer 4 and verifying the proper functioning of the system as a whole.
Subsequent to the actuation of this test device, through a new movement of the actuation key 2, along with a new actuation of the locking device 3, it will be possible to actuate the main connectors, energizing all the equipment connected therein.
The same reverse procedure occurs at the system shutdown, when the actuation key 2 should move conversely.
Thus, the referred safety device 1 allows the actuation of the system only in a secure environment, i.e., the actuation of the main equipment occurs only sequentially through an actuation key 2, wherein the test device is actuated first by means of the special actuation key 2, which has specific conformation, in order to actuate the main equipment posteriorly, so that in the event of any malfunction found in the equipment, whether electrical or mechanical, the first connector designed for testing, is passible to receiving an electric charge substantially lower than the main power, minimizing or even eliminating inconvenience arising from malfunctions in the electrical system or in the equipment itself.
The connector of test of the system functioning is released, primarily through the actuation key 2 that actuates the connectors of the test command and, then, the entire system is released through the same actuation key 2, actuating the main connectors in the bus bars 12 of the electrical system of the equipment coupled to the MCC cabinet 16, turning on all the equipment, being that these two steps, the actuation of the test device and the actuation of the main connectors, occur in the front of the extractable drawer 4 locked in the “closed” position.
The unlocking of the extractable drawer 4 occurs in the actuation of the test command and, posteriorly and in the sequence, the main connection command of the bus bars 12 of the system is actuated and, at this moment, the latch locks the front of the extractable drawer 4.
Thus, to better illustrate the functioning steps of this system, following is a table showing the moving and connection steps of the bus bars 12 of the extractable drawer 4.
More specifically, the safety device 1 for the locking and actuation of the electrical connectors arranged in an extractable drawer 4 for MCC cabinet 16, presents a degree of protection IP40 to IP55 and their compartmentalization forms up to 4B, in accordance with the NR10 requirements.
The sealing and locking of the extractable drawer 4 through a padlock or other equivalent locking means are also possible when the compartment is empty, due to the operating system of the extractable drawer 4 coupled to the door 13.
The positioner presents a specific encoding and has been developed for different types of extractable drawers 4.
On the other hand, the modular socket of command and the lateral or back network provide flexibility to the use of different types of connectors, such as PROFIBUS, ETHERNET, or output of power up to 100 A, etc.
The working mechanism of the extractable drawer 4 occurs through oriented gears and operates sequentially through mechanical interlocks.
In this way, in order to access the interior of the extractable drawer 4, to be possible to turn on or off the equipment connected to the MCC cabinet 16, to perform maintenance, among others, first, the actuation key 2 is inserted, positioning the system in the test mode, turning on the test command which can occur with the door 13 opened or closed or still, optionally only with the door 13 closed.
Subsequently, the actuation key 2 of the main equipment is actuated, remembering that the actuation of the system through the actuation key 2 only occurs if the test command is connected and the door 13 of the extractable drawer 4 is closed. Thus, there will be no movement of the connecting cables and the door 13 will be automatically locked.
Then, the actuation key 2 is returned to the test position, turning off the power input, at this stage necessarily with the door 13 closed, releasing the locks of the door 13 and of the test command.
Finally, it returns to the “disconnected” position by turning off the command, said operation is possible only and exclusively if the power input is disconnected.
The extractable drawer 4 also provides a mounting plate of components 11, positioned transversally.
The power transmission assembly and the mechanical lock assembly are constituted by a safety device 1, a gear assembly 6 and finally by an assembly of laminar plates 5 and 5A provided with elements that interconnect to the connectors for the actuation/locking of the system with the bus bars 12.
The safety device 1 is positioned in the door 13 of the extractable drawer 4 and is formed by a frame 10 of fixing and finishing of the safety device 1, opposite to which is positioned a drive bushing 9, this in turn, is fitted axially in a body 7 of the safety device 1, which provides a guide tab 23 and, fitted in the back section of this body 7 is positioned a coupling tab 8 of the drawer and the safety lock actuation.
On the other hand, the gear assembly 6 interconnected to the lock assembly, presents internally a central pendulous element 6A flanked by at least one gear 6B, 6C, passible of actuating the connection point for the test device, or still, actuating the connection point of the power input 15 or both.
Internal additional elements of the gear assembly 6 are spring elements 6F that permit the full functioning of all elements, in a precisely and adjusted way, being that each one of the gear assembly 6 presents a housing 6E in which these spring elements 6F are positioned.
The back face of the gear assembly 6 presents an ergonomic section 6H notably designed to receive the fingers of the operator, allowing the manual movement of the extractable drawer 4 when required.
The front face of the gear assembly 6 presents two small guide tabs 6D parallel to each other, positioned vertically, holding between them an interstice of housing for a third tab called guide tab 23, provided in the back section of the body 7 of the safety device 1, this being positioned in the back section of the lock assembly and fitting between the tabs 6D of the gear assembly 6, being said device designed to maintaining interlocked the whole safety device 1 and gear assembly 6.
Furthermore, the front face of the gear assembly 6 presents a central hole 24, which houses a switch 25 that receives the end of a special actuation key 2 for the actuation of the system, wherein said actuation key 2 is provided with a small salience that presses a small button 6G coupled to said switch 25, which when pressed by the salience in the end of the special actuation key 2, allows to rotate the referred actuation key 2, in conjunction with the pressing of the locking device 3 or the external button of safety, which is positioned next to the special actuation key 2, actuating the test device and then, by pressing again the locking device 3, allows to rotate the actuation key 2 to actuate the assembly of the power input 15 of the equipment where the extractable drawer 4 of the MCC cabinet is connected.
The locking device 3 presents a hole 26, which is designed to receive a safety padlock, the said padlock locks the entire assembly and prevents from being manipulated without permission.
It should be noted that the term “comprising” does not exclude other elements or steps and the use of articles “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2014 0075623 | Mar 2014 | BR | national |
This application claims priority to PCT Application No. PCT/BR2015/000043, having a filing date of Mar. 26, 2015, based on Brazilian Application No. 10 2014 0075623, having a filing date of Mar. 28, 2014, the entire contents of which are hereby incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/BR15/00043 | 3/26/2015 | WO | 00 |
