Method of constructing a structure for electric cable introduction in an explosion-proof facility

Abstract

An electric cable introduction structure in an explosion-proof facility includes a relay terminal box, a rack and an explosion-proof building. The relay terminal box connects an external electric cable to an internal electric cable. The rack is provided with the relay terminal box and sealed from the relay terminal box. Also, the rack relays the internal electric cable introduced from the relay terminal box. The explosion-proof building is provided with the rack outside and sealed from the rack and receives the internal electric cable from the rack.

What is claimed is:  
     
         1 . A method of constructing a structure for introduction of an electric cable, comprising: 
 constructing an explosion-proof building on a foundation shielded from the outside to accommodate a gas turbine such that said explosion-proof building can be disassembled and re-assembled for maintenance of the gas turbine;    constructing a rack in contact with said explosion-proof building along a wall of said rack such that said rack is not disassembled when said explosion-proof building is disassembled;    attaching a relay terminal box on an other wall of said rack;    connecting an external electric cable to an internal electric cable which extends from the gas turbine apparatus into said relay terminal box with said relay terminal box; and    providing sealing for said internal electric cable to seal said rack from said explosion-proof building.    
     
     
         2 . The method of  claim 1 , further comprising providing further sealing for said internal electric cable to seal between said relay terminal box and said rack.  
     
     
         3 . The method of  claim 2 , wherein the further sealing is provided at a portion of the other wall of said rack above said relay terminal box.  
     
     
         4 . The method of  claim 2 , wherein the further sealing is provided at a portion of the other wall of said rack below said relay terminal box.  
     
     
         5 . The method of  claim 1 , further comprising: 
 constructing a trench in a portion of said floor section adjacent to said explosion-proof building; and    arranging said external electric cable in said trench and introducing said external electric cable into said relay terminal box from said trench.    
     
     
         6 . A maintenance method in which: 
 an outer building formed on a foundation section, an explosion-proof building is in said outer building on a floor section formed on said foundation to accommodate a gas turbine, a rack is in contact with said explosion-proof building, and a relay terminal box is formed on a wall of said rack not in contact with said explosion-proof building, wherein said relay terminal box connects an external electric cable with an internal electric cable which extends from said gas turbine into said relay terminal box, and wherein sealing is provided for said internal electric cable to seal between said explosion-proof building and said rack;    said method comprising: 
 disassembling said explosion-proof building for maintenance of said gas turbine without disassembling said rack; and  
 reassembling said explosion proof building after said maintenance.  
   
     
     
         7 . The method of  claim 6 , wherein further sealing is provided for said internal electric cable to seal between said relay terminal box and said rack.  
     
     
         8 . The method of  claim 6 , wherein said further sealing is provided at a portion of the wall of said rack below said terminal box.  
     
     
         9 . The method of  claim 6 , wherein said further sealing is provided at a portion of the wall of said rack above said terminal box.  
     
     
         10 . The method of  claim 6 , wherein said further sealing is provided at a portion floor section adjustment to said explosion-proof building and said external electric cable is arranged in said trench and introduced into said relay terminal box from said trench.