DDG-51

                DDG 51 CLASS ADVISORY NR 02-93                                  

                                                                                

  AN-SPY-1D HIGH VOLTAGE POWER SUPPLY POTENTIAL SAFETY HAZARD                   

                                                                                

 REF/A/DOC/NAVSEA/-//                                                           

                                                                                

 REF/B/DOC/NAVSEA/-//                                                           

                                                                                

 REF/C/DOC/NAVSEA/-//                                                           

                                                                                

 NARR/REF A IS TECHNICAL MANUAL, NAVSEA SW279-CR-AEG-090/OT-                    

 146/SPY-1D.  REF B IS MRC 4560/R07-92.  REF C IS NAVSEA S9AAO-AB-              

 GOS-010, GEN SPECS FOR OVERHAUL OF SURFACE SHIPS, SECTION 602H.//              

 RMKS/1.  THIS ADVISORY IS INTENDED TO ALERT ALL PERSONNEL                      

 INVOLVED WITH THE OPERATION AND MAINTENANCE OF SUBJECT EQUIPMENT               

 TO A POTENTIAL SAFETY HAZARD WITH THE NEW HIGH VOLTAGE POWER                   

 SUPPLY INTERLOCKS IN THE AN/SPY-1D SYSTEMS.  THIS ADVISORY                     

 APPLIES TO DDG 51 AND FOLLOW.                                                  

                                                                                

 2.  BACKGROUND.  THE RIGHT BARRIER SCREEN AND CABLE ENTRY PANEL                

 HAVE CHEATABLE INTERLOCKS WHICH, IF BYPASSED, ALLOW HIGH VOLTAGE               

 TO EXIST WITHIN THE POWER SUPPLY.  THIS PROBLEM WILL BE CORRECTED              

 BY THE INSTALLATION OF ORDALT (O/A) 20213, WHICH WILL REPLACE THE              

 CHEATABLE INTERLOCK WITH A NON-CHEATABLE INTERLOCK.  ANTICIPATE                

 THIS O/A WILL BE AVAILABLE BY JUNE 1994.                                       

                                                                                

 3.  ACTION.                                                                    

      A.  PRIOR TO PERFORMING MAINTENANCE ON THE HIGH VOLTAGE                   

 POWER SUPPLY IAW REFS A AND B, ENSURE THAT THE FOLLOWING STEPS                 

 HAVE BEEN TAKEN:                                                               

                                                                                

                                                                                

           (1)  THE GROUNDING ROD IS CONNECTED TO THE "GROUND                   

 HERE" POINT AT ALL TIMES WHEN THE BARRIER SCREEN DOOR IS OPEN.                 

                                                                                

           (2)  HIGH VOLTAGE POWER SUPPLIES ARE IN LOCAL CONTROL                

 BEFORE OPENING THE CABLE ENTRY PANEL.                                          

                                                                                

           (3)  DISCHARGE AND GROUND ALL HIGH VOLTAGE CAPACITORS                

 AND EXPOSED HIGH VOLTAGE TERMINALS.  PERFORM THIS STEP SEVERAL                 

 TIMES TO ASSURE THAT ALL HIGH VOLTAGE TERMINATIONS HAVE BEEN                   

 COMPLETELY DISCHARGED.                                                         

                                                                                

           (4)  DO NOT BYPASS THE BARRIER SCREEN DOOR INTERLOCK                 

 (S7) OR THE CABLE ENTRY PANEL INTERLOCK (S6) IN THE HIGH VOLTAGE               

 POWER SUPPLY.                                                                  

                                                                                

      B.  ON THE FRONT PANEL OF EACH POWER SUPPLY INSTALL A                     

 WARNING SIGN FABRICATED IAW REF C READING AS FOLLOWS:                          

                          WARNING                                               

             HIGH VOLTAGE - DO NOT BYPASS BARRIER                               

             INTERLOCK S-7 OR PANEL INTERLOCK S-6                               

                                                                                

 4.  FOR COMNAVSURFLANT - REQUEST DDG 51 AND DDG 52 BE TASKED TO                

 ADHERE TO THE ABOVE SAFETY PRECAUTIONS.                                        

                                                                                

 5.  FOR SUPSHIP PASCAGOULA/BATH - REQUEST SHIPYARD PERSONNEL AND               

 DDG 53 AND FOLLOW SHIP PRECOMUNITS BE NOTIFIED TO ADHERE TO THE                

 ABOVE SAFETY PRECAUTIONS.                                                      

                                                                                

 6.  FOR NSWC PHD - SINCE ORDALT 20213 IS NOT IMMEDIATELY                       

 AVAILABLE, INCORPORATE THE FOLLOWING SAFETY PRECAUTION INTO                    

 APPLICABLE MRC'S (Q-8, Q-17, 18M-4, AND 60M-10) OF REF B PMS -                 

 "DO NOT BYPASS BARRIER INTERLOCK S-7 OR PANEL INTERLOCK S-6".                  

                                                                                

 7.  THIS ADVISORY HAS NO IMPACT ON EOSS, CMMP OR TECHNICAL                     

 DOCUMENTATION.  IT WILL BE CANCELLED UPON COMPLETION OF ORDALT                 

 20213 IN ALL APPLICABLE SHIPS.                                                 

                                                                                

 8.  POC IS MR N. S. SMITHSON, PMS400F511, DSN: 332-5981 OR COMM                

 (703) 602-5981.  NSWC PHD TECHNICAL POC IS MR J. CHUNG, CODE                   

 4C11, DSN: 551-8689 OR COMM (805) 982-8689.//