CG 47 CLASS ADVISORY NR 13-95
AN-SPS-55 RADAR MAN ALOFT CIRCUIT SAFETY HAZARD
RMKS/1. THIS CLASS ADVISORY ALERTS ALCON TO A SAFETY HAZARD
ASSOCIATED WITH THE INSTALLATION OF SPS-55 FIELD CHANGE FOUR
(ANTENNA PEDESTAL AB-1300) AND PROVIDES CORRECTIVE ACTION.
2. BACKGROUND. EVALUATION OF SPS-55 ANTENNA DRIVE MOTOR FAILURES
AFTER INSTALLATION OF FIELD CHANGE 4 ON AEGIS CRUISERS IDENTIFIED AN
INCOMPATIBILITY BETWEEN THE SHIP'S 2MD MAN ALOFT CIRCUIT AND THE NEW
ANTENNA PEDESTAL WIRING WHICH DID NOT TAKE INTO ACCOUNT THE AEGIS
UNIQUE MAN ALOFT CIRCUIT. CONSEQUENTLY, THE WIRING CHANGES
ASSOCIATED WITH FIELD CHANGE 4 RESULT IN THE MAN ALOFT CIRCUIT
INDICATION LIGHT IN CIC BEING INCORRECTLY WIRED. THIS CAUSES
PREMATURE DRIVE MOTOR FAILURE AND AN ELECTRICAL SAFETY HAZARD BECAUSE
OF UNANTICIPATED VOLTAGES WITHIN THE SYSTEM.
3. ACTION.
A. CG 47 CLASS SHIPS HAVING COMPLETED INSTALLATION OF FIELD
CHANGE 4 (AB-1300 ANTENNA PEDESTAL) TAKE CORRECTIVE ACTION AS
FOLLOWS (FC-4 INSTALLED ON ALL SHIPS EXCEPT CG 52, 53, 54, AND 57):
(1) DEENERGIZE THE SPS-55 RADAR AND TAG OUT IAW CURRENT
SHIPS DIRECTIVES. IMPLEMENT MAN ALOFT RESTRICTIONS IN ACCORDANCE
WITH SHIP'S STANDARD OPERATING PROCEDURES.
(2) OPEN AND TEST FOR VOLTAGES PRESENT IN THE MAST-MOUNTED
SWITCH BOX 09-01-06 IAW NSTM CHAPTER 300 (WORKING ON DEENERGIZED
EQUIPMENT SECTION). IF ANY VOLTAGES ARE PRESENT LOCATE, DEENERGIZE
AND TAG OUT SOURCE.
(3) MAKE THE FOLLOWING WIRING CHANGES IN THE MAST-MOUNTED
SWITCH BOX 09-01-06:
(A). DISCONNECT RED WIRE 5-2MD3 FROM TERMINAL 05 AND
RECONNECT THIS WIRE TO TERMINAL 08. RELABEL THIS WIRE 8-2MD3.
(B). DISCONNECT BLACK WIRE 1-2MD2 FROM TERMINAL 01
AND RECONNECT TO TERMINAL 02. RELABEL THIS WIRE 2-2MD2.
(C). DISCONNECT THE JUMPER BETWEEN TERMINALS 02 AND
08 AND RECONNECT IT BETWEEN TERMINALS 06 AND 09.
B. CG 47 CLASS SHIPS NOT YET HAVING RECEIVED FIELD CHANGE 4 (CG
52, 53, 54, AND 57) SHOULD VERIFY/CORRECT WIRING AS DESCRIBED IN
PARA 3.A ABOVE WHEN PEDESTAL UPGRADE IS INSTALLED.
4. FOR COMNAVSURFLANT/COMNAVSURFPAC - RECOMMEND CG 47 CLASS SHIPS BE
TASKED TO IMPLEMENT WIRING CHANGES/INSPECTION AS DETAILED IN PARA 3
ABOVE AND TO REPORT TO TYCOMS AND AEGIS PROG MGR UPON COMPLETION.
5. FOR SEA 91W3D - THE MAN ALOFT CIRCUIT, 2MD, IS PART OF THE AEGIS
SAFETY REQUIREMENTS, CG 49 SHIP SPEC SECTIONS 403.D AND 437, AND WAS
INSTALLED AS PART OF SHIP INTEGRATIONS OF SPS-55 AT THE TIME OF
CONSTRUCTION. REQUEST YOU MODIFY FIELD CHANGE 4 TO INCORPORATE
WIRING CHANGES FOR THIS CIRCUIT FOR AEGIS CRUISERS PRIOR TO FURTHER
INSTALLATIONS.
6. THIS ADVISORY HAS NO IMPACT ON EOSS, PMS OR CMMP. IT WILL BE
CANCELLED WHEN ALL SHIPS HAVE REPORTED COMPLETION OF REQUIRED
CORRECTIVE ACTION.
7. POC IS MR. N. S. SMITHSON, PMS400F511, DSN 332-5981, EXT 133 OR
COMM (703) 602-5981.//
BT
CG-47