at each emergency switchboard. They consist ofcasualty power terminals that are connected to thebus bars through circuit breakers. Some shipshave small diesel-driven generators which aredesigned for casualty power use only; thesegenerators are very small and have a minimumof control equipment. Casualty power terminalsare installed on power panels that feed equipmentdesignated to receive casualty power; these ter-minals may also be used as a source of supply tothe casualty power system if power from the per-manent feeders to the panels is still available.The casualty power system is either a.c. ord.c., as appropriate for the particular installation.Only the a.c. system is described here. The d.c.system is similar to the a.c. system, but uses dif-ferent types of cables and fittings.The portable, thermoplastic-covered orneoprene-covered cables for the a.c. casualtypower system are stowed in racks in convenientlocations throughout the ship. Each cable containsthree leads (conductors), colored black, white, andred. This same color code is used in all three-wirepower circuits throughout the ship.On smaller ships, the bulkhead terminals forthe casualty power system are arranged so as toallow for one horizontal run of the portable cablealong the main deck, and generally, if possible,inside the deck house. On larger ships, generallythere are terminals for two horizontal runs ofcable, one port and one starboard. These arelocated on the second deck. The terminals extendthrough the bulkhead and project from it on eachside, and do not impair the water-tight integrityof the compartments in which they are installed.The cable ends are inserted into the holes that areprovided around the outer rim (curved surface)of the terminal. Both the rim and the face of eachterminal have three groups of three holes each,into which fit the square-shanked, insulatedwrenches that are used to secure the cables in theterminal. Two square-shanked wrenches are pro-vided in the rack mounted on the bulkhead at eachpoint where they will be required. These wrenchesMUST be kept in the racks at all times when theyare not actually in use.The riser terminals for the casualty powersystem are similar to the bulkhead terminals, ex-cept that they are connected to other riser ter-minals by vertical runs of permanently installed,armored cable. The risers and the riser terminalscarry the casualty power from the level of thegenerators to the main deck and second decklevels.Portable switches are sometimes provided onthe bulkheads, near the cable racks. These are sim-ple ON-OFF switches which have special holes foruse with the portable cables.The terminals and the cables in an a.c. casualtypower system are marked so that they can be iden-tified easily when the system is being connected.The faces of the terminals are marked A, B, andC, and the three leads on each cable are coloredblack, white, and red, respectively. When connect-ing the cables to the terminals, you connect theblack lead to A, the white lead to B, and the redlead to C. Since the letters and the colors cannotbe seen in darkness, the terminals are further iden-tified by molded knobs in the A, B, and Careas—one knob for A, two for B, and three forC. The cable leads are identified by servings oftwine—one for black, two for white, and threefor red. Each serving of twine is about 1 inchwide. Thus each lead and its corresponding posi-tion in the terminal can be identified merely byfeeling the leads and matching the number ofpieces of twine on each lead with the number ofraised knobs on the terminal. (In older ships, thecasualty power fittings may still have identifyingV-shaped notches in the outer edge instead ofraised knobs.)CAUTION: When connecting a run of casu-alty power cable, ALWAYS CONNECT FROMTHE LOAD BACK TO THE POWER SUPPLY!By rigging the system in this manner, you willavoid working with an energized cable. Also beSURE to shut off the normal supply to any powerpanel before you connect the casualty power cableto the terminals on the power panel.EMERGENCY FIRE PUMPSMost ships have electric-driven fire pumpslocated outside the engineering spaces. Thesepumps furnish water under presssure to their ownpiping system or to the ship’s firemain. Provisionsare made for different sources of electrical powerto these pumps: normal and alternate supply fromthe ship’s service generators, emergency supplyfrom the diesel-driven emergency generators, andthe casualty power system itself.ENGINEMAN 1 & C9-12
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