Patent Publication Number: US-11653457-B2

Title: Submersible control panel

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority, under 35 U.S.C. § 119(e), of provisional application No. 62/972,395 filed Feb. 10, 2020; the prior application is herewith incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates, generally, to a submersible control panel for housing electronic components. 
     Control panels for pump controls for storm and lift stations are subject to harsh environmental conditions including high winds in excess of 175 mph and flooding such as during king tides. In order to avoid flooding, the inventor considered providing control panels that have built in lifting devices which would lift the control panels up to six or more feet upon the detection of water intruding into the area of the control panel. However, it was determined that such a lifting devices would be complex devices and would be subject to failure and thus not reliable. Therefore, there is a need for control panels that have flood proof construction. 
     Description of the Related Art 
     U.S. Pat. No. 10,362,362 to Midday discloses a system for environmental sealing of electrical enclosures. The enclosure has interior space that is accessible through an opening. A door or cover selectively closes the opening. The enclosure cabinet is manufactured of numerous parts and has holes, joints, gaps, seams and/or fasteners. Electrical control devices are mounted in the cabinet. To this end, Midday discloses that a thick-film elastomeric coating is on an outer surface of the cabinet. The coating has a thickness of at least 0.6 mm to provide a monolithic bridging layer over holes, joints, gaps, seams and/or fasteners to prevent environmental contamination from penetrating the cabinet. As the coating in a monolithic structure that covers the enclosure, the construction results in a complex coating that is subject to being compromised by any type of damage to the coating, which could occur during installation or flying debris and is thus not suitable for or capable being submersed in water for a prolonged period of time while ensuring that the interior of the cabinet remains free of water. 
     US 2015/0282363 to Bier discloses an enclosure for submersible network connectors that includes electrode openings that receive electrodes that pass into the top of the cabinet body. The openings each receive a terminal or electrode. The electrode has insulating material (polyester, fiberglass, porcelain, epoxy, etc.) to electrically isolate the terminal/electrode from the cabinet. The insulating material is sealed with respect to the cabinet body by an O-ring or the terminal/electrode is partially encapsulated in a polymeric (e.g., rubber) material that seals and electrically isolates the electrode/terminal. The sealing of Bier is susceptible to leaking at the O-ring or rubber seal to the body. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide a submersible control panel system that overcomes the herein-mentioned disadvantages of the heretofore-known devices of this general type, which are able to remain water-tight for at least 24 hours after being submerged in water and are able to be implemented in flood prone areas. 
     With the foregoing and other objects in view there is provided, in accordance with the invention, a submersible control system with a control panel. The control panel has a frame to house electronic components the frame has a connection opening for wiring for electrical connection. At least one door is attached to the frame in a water-tight manner. A conduit is sealed in a water-tight manner with respect to the connection opening. The conduit is filled with an epoxy to seal an interior of the conduit in a water-tight manner with respect to electrical wiring passing through the conduit into the frame. The control panel will remain water-tight for at least 24 hours after being submerged. 
     In accordance with another feature of the invention, the connection opening has a hub welded onto said frame to be water-tight to said frame. The conduit has a threaded connection to said hub. 
     In accordance with another feature of the invention, a porous material is disposed in said conduit at a bottom end of said conduit. The porous material defines a damper for preventing said epoxy from flowing out of said conduit during filling of said epoxy into said conduit. 
     In accordance with another feature of the invention, the porous material is a sponge that engages an inside diameter of said conduit. 
     In accordance with another feature of the invention, the sponge has material properties configured to allow the wires to be pierced through said sponge. 
     In accordance with another feature of the invention, an inner door is disposed inside said control panel. The inner door divides an interior of said control panel and defines an area behind said inner door to isolate high-voltage components of the control panel. 
     In accordance with another feature of the invention, rails are disposed on a sidewall of said frame. The rails adjustably mount said inner door in a front to back direction of said control panel. 
     Additionally, there is provided, in accordance with the invention a method of providing a submersible control system that includes to provide a water-tight control panel with a connection opening for electrical wiring. To provide a conduit and pass electrical wiring through the conduit. To connect the conduit to the opening with a water-tight connection and fill the conduit with epoxy. Seal the interior of the conduit to the electrical wiring. 
     In accordance with another feature of the invention, prior to the filling step: provide a porous material damper; pierce the wiring through the porous material damper; insert the porous material damper into the conduit and engage an inside diameter of the conduit therewith. 
     In accordance with another feature of the invention, prior to the filling step: provide a porous material damper as a sprayable foam; spray the porous material damper into the bottom end of the conduit around the wiring and fill a gap between the wiring and an inside diameter of the conduit. 
     Other characteristic features of the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a submersible control panel, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG.  1    is a front view of a submersible control panel according to the invention; 
         FIG.  2    is a perspective view of the submersible control panel; 
         FIG.  3    shows a side view of the submersible control panel; 
         FIG.  4    is a bottom view of the submersible control panel without the floor stands in place; 
         FIG.  5    is a top view of the submersible control panel; 
         FIG.  6    is a section view of the submersible control panel along A-A of  FIG.  3   ; 
         FIG.  7    is an enlarged section view of the submersible control panel through an electrical connection for the panel; 
         FIG.  8    is a front view of a submersible control panel with a single door according to the invention; and 
         FIG.  9    is a section view of the submersible control panel along B-B of  FIG.  5   . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In all the figures of the drawing, sub-features and integral parts that correspond to one another bear the same reference symbol in each case. 
     Referring now to the figures of the drawings in detail and first, particularly, to  FIGS.  1  and  2    thereof, there is shown a submersible control system with a control panel  1 . The submersible control panel  1  provides a control system that does not require being installed at the 100 years flood level, namely 1.5 or 2 ft above ground level. In some cases such as the Venetian Islands the control stations are installed a least 8 ft above sea level. 
     The submersible control panel  1  is constructed to maintain a NEMA 4× rating and be submersible in 6+ feet of water for at least 24 hours and must keep water from entering inside the interior of the control panel  1 . The control panel  1  is defined by a frame or body  10  and at least one outer door  11  mounted thereon. The body  10  and door(s) are preferably manufactured of 12 gauge 316L stainless steel. The body encloses five side of a rectilinear volume. The body  10  has an opening which is closed by the door(s)  11  and a center post  12  vertically spans the opening and acts as a mullion for the doors  11  when two doors are provided. 
     The doors  11  are attached to the body  10  of the control panel  1  in a water-tight manner by continuous hinges running the length of the doors  11 . The doors  11  are provided with seals about the periphery thereof that seal the doors  11  in a water-tight manner for submersion of the panel. In addition, electrical connection via conduits  21  are also epoxy sealed to prevent the penetration of water. The doors  11  are secured by screw clamps  5  disposed along three sides of the doors  2 . A key locking handle can be provided on the doors  11 . The body  10  has stainless steel welded legs or floor stands  15  at opposing ends of a base of the body  10 . 
     The interior of the control panel  1  includes inner doors  16  mounted on rails  17  disposed on sidewalls  18  as shown in  FIGS.  3  and  6   , where  FIG.  6    is a section taken behind the outer doors  11 . The inner doors  16  may be aluminum. The inner doors  16  can be slid depth wise into and out of the panel  1  to accommodate breakers that are disposed behind the inner doors  16  and which are provided to operate the station. The inner doors  16  allow maintenance of electrical control components (disposed in front of the inner doors) without the inner doors having to be opened and to allow a service person not be required to employ PPE (Personal Protection Equipment) requirements by NEC code. The set distance on the rails  17  for the inner doors  16  from the back wall is determined by the required breakers that are mounted in the behind the inner doors  16  and this distance varies according to the frame size of the breakers disposed in the control panel  1 . 
     The base of the body is provided with connection openings  19 . The connection openings  19  have connection hubs  20  that are welded water-tight to the openings  19 . The hubs  20  are stainless steel and are threaded for connection of rigid conduits  21 , which each have a mating thread corresponding to the threads on the corresponding hub  20 . The conduits are preferably 16″ in length. A PTFE tape can be used at the threaded connections between the hubs  20  and the conduits  21  to improve the seal. The rigid conduits  21  can be “steel rigid metal conduit” as provided by Wheatland Tube, which are hot-dip galvanized steel tubes. Any hubs  20  not required for wiring requirements of the panel  1  are provided with a threaded plug  22  that seals the hub  20  in a water-tight manner. The plug  22  and hub  20  connection can also be provided with the thread tape for ensuring the sealing of the plug  22  to the hub  20 . 
       FIG.  7    shows an enlarged section of the hub area of the panel. As shown in  FIG.  7   , the bottom of the conduit  21  is provided with a porous material damper  23  such as a sponge  23  that conforms to the inside diameter of the conduit  21  and preferably has a length of 1.5 inches in the longitudinal direction of the conduit  21 , which preferably has a length of 16 inches. The wiring W for the hub  20  is passed through the sponge  23  by simply being pierced through the sponge  23 . An epoxy  24  is provided in the conduit  21  and saturates the sponge  23  and is hardened to seal the conduit  21  to the wires W over the longitudinal extent of the sponge  23  and above the sponge  23  to the height which the epoxy is filled. A suitable epoxy is EPIC R1074-06/H4030-02, which is a premium fire retardant epoxy potting compound from EPIC RESINS, but the epoxy is not limited to such as any comparable epoxy may be used. The sponge  23  serves as a damper in the conduit to prevent the liquid epoxy from running out of the conduit  21  and allows the epoxy  24  to set without running out of the conduit  21 . A suitable sponge is the type used in packaging for reducing impact during shipping, but is not limited to such material. The sponge needs to have the material properties that allow for the wiring to be pierced through the sponge  23 , which provides for a tight fit between the sponge  23  and the wires W. The porosity of the sponge material is selected to minimize the flow through of the epoxy, while still allowing the sponge to become saturated before the epoxy begins to set. Alternatively, the porous material damper  23  can be provided a spray foam  23  that is applied at the bottom end of the conduit  21 . A suitable foam is Fire Block Foam by 3M® with the manufacturer ID: FB-Foam-Orange, but is not limited to such foam. 
     The body is also provided with lifting lugs  14  that allow for rigging to place the control panel  1 . 
     The method of providing the connection of the conduits  21  onto the hubs  20  is described with respect to  FIG.  7   . The required wires W for a respective hub  20  are pierced through the sponge  23  and fed through until the required length to connect to the corresponding control component(s) in the panel  1  is reached. The wires are fed through the conduit  21  and the conduit  21  is threaded onto the corresponding hub  20 . The sponge  23  is inserted into the lower end of the conduit  21  and engages the inside diameter of the conduit  21 . The epoxy  24  is filled into the connected conduit  21  and allowed to cure. If the porous material  23  is provided as the spray foam, the wires W are passed through the conduit to the required amount. The foam is sprayed into the bottom of the conduit and then the epoxy  24  is filled into the conduit  21 . 
     The method and construction of the invention provides for the water-tight submersible panel that is made water-tight at the installation site at the time of connection and thus allows for the electrical connection of the panel in a precise and reliable way. 
     Once the flood waters have resided, the control panel  1  maintains operation with no structural changes or modifications, nor is there a need of any special panels to guarantee the sealing of the control panel  1  as it is installed in a water-tight manner. The control system will be able to function and provide municipalities with full confidence that their “Lift Sewage or Storm Pump Stations” are fully functional and free of any electrical hazard. Thus, the submersible control panel  1  provides normal functionality and ability for residents after a severe, storm or hurricane. 
     The control panel  1  withstands 175 mph wind tests and maintains water-tightness when submersed at 6 feet+ and still function at 100%.