FFG 7 CLASS ADVISORY NR 04-93
MK 36 DECOY LAUNCHING SYSTEM(DLS) POWER SUPPLY
CIRCUIT BREAKER WITH AUXILIARY SWITCH
REF/A/RMG/NCSL PORTSMOUTH/121505ZFEB93/-/NOTAL//
REF/B/RMG/NSWC ORD LOUISVILLE/081530ZMAR93/-/NOTAL//
NARR/REF A IDENTIFIED A FFG 7 CLASS MK 36 DECOY LAUNCHING SYSTEM
SAFETY PROBLEM. REF B REQUESTED THAT NAVSEA RESOLVE
CONFIGURATION CONTROL PROBLEM WITH CIRCUIT BREAKERS CONTROLLING
POWER TO LAUNCHERS ONE AND TWO.//
POC/A. FINAZZO/CIV/PMS330TS2/WASHINGTON DC/TEL:DSN 332-1305
/TEL:(703) 602-1305//
RMKS/1. THIS ADVISORY PROVIDES GUIDANCE FOR VERIFYING
INSTALLATION OF CORRECT CIRCUIT BREAKER, REPLACEMENT PROCEDURES
IF REQUIRED, AND INTERIM SAFE MAINTENANCE PROCEDURES FOR MK 36
DLS LAUNCHERS ONE AND TWO.
2. BACKGROUND. REF A IDENTIFIED A MK 36 DLS SAFETY PROBLEM
WHICH COULD RESULT IN INADVERTENT DECOY LAUNCHING. SOME FFG 7
CLASS SHIPS DO NOT HAVE THE CORRECT CIRCUIT BREAKERS INSTALLED
FOR LAUNCHERS ONE AND TWO. THE PROPER CIRCUIT BREAKER NOT ONLY
FEEDS THE MK 160 PWR SUPPLY OF EACH LAUNCHER BUT ALSO CONTAINS AN
INTERNAL AUXILIARY SWITCH THAT OPENS THE 28VDC BACK-UP BATTERY
CIRCUIT WHEN THE BREAKER IS IN THE OFF POSITION. INSTALLATION OF
A CIRCUIT BREAKER WITHOUT AN INTERNAL AUXILIARY SWITCH CREATES
THE POTENTIAL FOR INADVERTENT LAUNCH WHILE PERFORMING SYSTEM
MAINTENANCE. AS REQUESTED REF B, THE FOLLOWING GUIDANCE IS
PROVIDED TO IDENTIFY AND CORRECT THE PROBLEM.
3. ACTION.
A. EXAMINE SUSPECT CIRCUIT BREAKERS FOR LAUNCHERS ONE AND
TWO IN POWER PANEL 01-183-2 LOCATED IN AIRNAV/ECM ROOM
(01-180-0-Q). PART NUMBER FOR CORRECT BREAKER IS CAT. NO.
ETN2750-10, WHICH IS STAMPED ON THE BREAKER. IF UNABLE TO
DETERMINE P/N FOR BREAKERS, CHECK THE MK 160 METER FOR 28V
BATTERY CIRCUIT WITH BREAKER IN OFF POSITION. METER SHOULD READ
ZERO VOLTS WITH CORRECT BREAKER INSTALLED.
B. IF INCORRECT BREAKER IS INSTALLED, PROCURE CORRECT
BREAKER LISTED ABOVE AND 30 FEET OF TYPE F3 CABLE. THE ORDERING
DATA FOR THE CIRCUIT BREAKER WITH AN AUXILIARY SWITCH IS
AQB-A101, 15A ELEMENT, APL NO. 14032175, NSN 5925-01-139-3139.
WITH 28VDC AND 440VAC POWER SECURED AND PROPERLY TAGGED-OUT,
REMOVE EXISTING CIRCUIT BREAKER AND INSERT CORRECT BREAKER WITH
AUXILIARY SWITCH. REMOVE AND DISCARD 2-CONDUCTOR CABLE RUNNING
FROM BREAKER TO MK 160 POWER SUPPLY. RUN NEW TYPE F-3 CABLE FROM
BREAKER TO MK 160 POWER SUPPLY. USE TWO CONDUCTORS TO RECONNECT
TWO POLES OF THE BREAKER TO THE MK 160 440VAC SUPPLY (THIRD POLE
OF THE BREAKER IS NOT USED). USE THE TWO REMAINING CONDUCTORS TO
CONNECT THE AUXILIARY SWITCH (NORMALLY OPEN CONTACTS) OF THE
CIRCUIT BREAKER TO THE 28VDC BATTERY CIRCUIT WITHIN THE MK 160
POWER SUPPLY. ONE SIDE OF NORMALLY OPEN CONTACTS OF AUXILIARY
SWITCH SHOULD BE CONNECTED TO THE POSITIVE SIDE OF THE BATTERY,
COMMON SIDE OF AUXILIARY SWITCH SHOULD BE CONNECTED TO TB4-7 OF
MK 160 POWER SUPPLY. UNUSED WIRE FROM AUXILIARY SWITCH SHOULD BE
SECURED INSIDE POWER PANEL.
C. IF POWER MUST BE SECURED TO PERFORM MAINTENANCE ON
LAUNCHERS 1 OR 2 PRIOR TO INSTALLATION OF CORRECT BREAKER, ENSURE
BATTERY LEAD IS DISCONNECTED IN ADDITION TO DISABLING THE 440VAC
POWER VIA THE EXISTING BREAKER.
4. FOR COMAVSURFLANT/COMNAVSURFPAC - RECOMMEND FFG 7 CLASS SHIPS
BE TASKED TO COMPLY WITH PARA 3 ACTION AT EARLIEST OPPORTUNITY.
REQUEST ALL SHIPS REPORT FINDINGS AND, IF REQUIRED, COMPLETION OF
CORRECTIVE ACTION TO NAVSEA PMS330, INFO TYCOM, NSWC ORDSTA
LOUISVILLE (CODE 90F1) AND LBNSY (CODE 270.2). INSTALLATION OF
CORRECT BREAKER WILL BE VERIFIED AS PART OF FUTURE INSTALLATIONS
OF SHIPALT FFG7-176K, MK 36 DLS EXPANSION.
5. THIS ADVISORY HAS NO IMPACT ON EOSS, PMS, CMP OR TECHNICAL
DOCUMENTATION. IT WILL BE CANCELLED WHEN ALL FFG 7 CLASS SHIPS
HAVE REPORTED COMPLETION OF PARA 3 GUIDANCE.//
CG-47