0301_A_M10 AMR Supply Fan Overhaul and Motor Rewind.docx

USNS Drew

( TAKE 10 )

ABSTRACT:

This item describes the requirement to remove, overhaul, rewind, dynamically balance, and reinstall the M10 Supply Fan Assembly.

REFERENCES:

2.1 T9513-AE-MMC-10, Ventilation Fans and Dampers

2.2 MSFSC SWIRRR #19 for AC Motors.

ITEM LOCATION AND DESCRIPTION:

3.1 Location/Quantity:

3.1.1 Location: 2-58-1 Aft Service Tunnel, STBD side 2nd Deck

3.1.2 Quantity: One (1) Supply Fan Assembly

3.2 Item/Description/Manufacturers Data:

3.2.1 Toshiba Model 063638-MTR (P04100KIADAKCT01), 460VAC, 3 Ph, 60 Hz, 125/41 AMPS, 1785/892 RPMs, Frame: 444TZ

3.2.2 Bill of Material (Contractor Furnished): None

GOVERNMENT FURNISHED EQUIPMENT/MATERIALS/SERVICES:

NOTES:

5.1 This ship contains High Voltage (HV) electrical systems. The Contractor and Subcontractors shall obey all posted and verbal instructions regarding safety and exclusion from High Voltage areas. At no time shall a Contractor or Subcontractor approach, work on, or enter a High Voltage area without proper authorization.

5.2 The Ship’s electrical color-coding does not follow consistent color scheme. The ship is known to have current carrying conductors colored green, blue, black, and white. The Contractor shall assume all electrical cables are hot until tested otherwise. The Contractor shall test all electrical cables to ensure they are dead prior to working on the item.

QUALITY ASSURANCE REQUIREMENTS: None additional

STATEMENT OF WORK REQUIRED:

5.3 Mechanically and electrically isolate the M10 AMR Supply Fan. Mark the motor/line leads to ensure correct phase rotation during re-connection.

5.4 Unbolt the assembly from the foundation. Bag/tag and retain fasteners for reinstallation.

5.5 Rig out the assembly off the vessel and transport to a certified electric motor repair facility for overhaul. Ships crane can be used to crane the motor to the pier. Note: The designated route for removal and return of the equipment is through the pilot embarkation door ("sally port") on the STBD side. The contractor shall verify clearances prior to removal.

5.6 Disassemble the motor and inspect the motor stator windings and rotor.

5.7 Inspect end bell bearing housings for damage.

5.8 Rewind the two-speed motor, with specific attention to correcting the failed High-Speed winding.

5.9 Dip and Bake the motor stator.

5.10 Remove the drive end and non-drive end bearings from the rotor.

5.11 Install new bearings and seals. Renew internal leads as required. Completely reassemble the motor, liberally applying anti-seize to all fasteners. Renew assembly hardware and gaskets on covers, inspect plates, and between the external connection box and frame.

5.12 Reassemble the motor.

5.13 Bench test the refurbished motor to ensure voltage and current are stable and within acceptable tolerance under no-load condition. MSCREP will witness the shop test.

5.14 Perform dynamic balancing of the fully assembled unit (motor with blades on) to ensure vibration is within acceptable operational tolerances prior to shipboard installation.

5.15 Transport the assembly back to the vessel, rig down to their respective space, and stage near the foundation.

5.16 Clean the existing foundation to bare metal, removing all rust, scale, and debris. Inspect for damage and report any discrepancies to the MSCREP.

5.17 Install the assembly on the foundation. Verify and correct any "soft foot" conditions using stainless steel shims.

5.18 Reconnect all electrical leads and terminate in accordance with standard marine practices.

5.19 Prior to energizing, perform an Insulation Resistance (Megger) test of the motor windings and supply cables. Submit results to the MSCREP.

5.20 Touch up any paint damaged during transport and installation.

5.21 Operational Testing: Coordinate with Ship's Force to run the fan across all operational modes for a minimum of one (1) hour. The contractor shall monitor and record bearing temperatures, vibration levels, and phase currents (amps). Submit a final operational test report to the MSCREP for acceptance.

5.22 Ship's Force shall conduct vibration testing to verify the unit meets operational standards. The contractor shall remain available to provide corrective action if the unit fails to meet vibration limits during this final check.

5.23 Preparation of Drawings/Documentation:

5.23.1 Provide the MSCREP with an electronic copy of the detailed service report to include the results of disassembly and inspection and all electric motor testing accomplished, rotor balancing results/corrections made, MFG and part numbers of the new bearings installed.

GENERAL REQUIREMENTS: None additional.

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