Statement_of_Work.doc

STATEMENT OF WORK (SOW)

1. SCOPE:

1.1 Rotating Electrical Equipment; rewind

2. REFERENCES:

2.1 Standard Items

2.2 S9086-KC-STM-010/CH-300, Electric Plant - General

2.3 S9086-KE-STM-010/CH-302, Electric Motors and Controllers

2.4 S6260-BJ-GTP-010, Electrical Machinery Repair, Electric Motor, Shop Procedures Manual

2.5 88305-51, Reliance Electric Motor Drawing

2.6 MIL-STD-167, Mechanical Vibration of Shipboard Equipment (Type I- Environmental and Type II-Internally Excited)

3. REQUIREMENTS:

3.1 Contact Contracting Officer’s Representative (COR) to arrange for and pick-up motor from Government location and transport to Contractor facility.

3.2 Match mark, disassemble and inspect the equipment, using References 2.2 through 2.5 for guidance.

3.2.1 Accomplish a core loss test and record data prior to stripping and cleaning of the core in accordance with Paragraphs 300-4.5.6 and 300-4.5.6.1 paragraph (2) of References 2.2. and Paragraph 2-30 of Reference 2.4.

3.2.2 Inspect for hot spots in accordance with the paragraph 300-4.5.6.1 a-2

3.2.3 Verify the temperature limitations of the core material prior to exercising the burnout oven option. When a burn-out oven is used, the maximum surface temperature of the laminated iron surface should be measured on the iron by thermocouple and shall not exceed 370 °C (698 °F).

3.2.4 After burnout, strip the windings and insulation. Record all winding data (size and type of magnet wire, number of turns per coil, coils per pole, pitch, number of poles, number of slots, connections, and similar data) and compare with the specifications of 2.5. Refer to Paragraph 300-4.5.7.2 (Stripping Procedures) of 2.2 and 2.4 Paragraph 8-13 (Stripping Procedures) and Figure 9-1 (Motor Repair Identification Sheet) for guidance.

3.2.4.1 After stripping of windings, accomplish core loss test in accordance with Paragraph 300-4.5.6 of 2.2

3.2.5 Record winding data and verify conformance of recorded data to the manufacturer's winding data.

3.2.5.1 Pull any sprung laminations together with heavy wire before bead blasting. Clean laminated surfaces by bead blasting using glass beads or equivalent organic materials. Sand or grit blast media is prohibited.

3.2.5.2 Accomplish a core loss and record data

3.2.5.3 Inspect for hot spots in accordance with paragraph 300-4.5.6.1 a-2

3.2.5.4 If the core loss tester's evaluation of the core was marginal and there were no hot spot areas located, attempt to lower the watts-per-pound loss below the marginal limit by (1) bumping or pounding the iron with a heavy mallet (no-bounce) which will cause the shorted laminations to vibrate and break up or (2) using suitable tool and drag the surface of shorted laminations in an attempt to break up shorted areas.

3.2.5.5 Fused or welded laminations may be cleared by grinding or filing, and shorted laminations may be separated and reinsulated by pounding or cracking/shocking” the end of the core stack with a heavy mallet or brass bar. Care should be taken not to damage the laminations during this procedure

3.2.5.4 Accomplish a core loss test and record data. Refer to Paragraph 300-4.5.6.1.2 of 2.2 and Paragraph 2-30 of 2.4 for additional guidance.

3.2.6 After satisfactory core loss testing, dip core in a 20 percent solution of varnish MIL-I-24092 and dry. In localities where MIL-I-24092 does not meet state and local Air Pollution Control District (APCD) standards, spray the iron core with a clear air-drying varnish.

3.2.7 Protect machined surfaces. Accomplishment of cleaning and painting for equipment housing exterior, fan(s), core and interior and exterior of each end bell shall be in accordance with NAVSEA Standard Item 009-32, Table 5, Line 9.

3.3 Inspect non-wound rotors for loose or cracked bars, localized overheating, and rubbing. Record inspection data. Glass bead blast the rotor core and apply air dry varnish or thin class F varnish for rust prevention. Protect the machined shaft surfaces from damage before bead blasting.

3.4 Inspect and dimensionally measure end bells housing bores, rabbet fits, shaft bearings journals, outside bearing cap, seal fit areas for damage, defects or deterioration. Acceptance Criteria: Areas showing raised metal, distortion, cracks, dents, scores, or pitting which will result in incorrect fit-ups.

3.4.1 Machine or manually hand work minor defects found as necessary to endbells and frames mating surfaces. Blend in any high spots. Use 2.5, for dimensional criteria and Paragraph 6-8.6 of 2.4 (Shaft and Design Housing) for additional guidance. Record inspection data.

3.5 Plate repair any unsatisfactory bearing journals and bearing housing bores/cartridges including shaft coupling surface.

3.5.1 Undersize steel bearing seats may be repaired by plating in accordance with 2.4, Table 6-5, and oversize bearing seats by machining. Final machining of shaft bearing seats shall be accomplished by grinding to maintain seat hardness.

3.5.2 After reworking, measure bearing seats at three locations (inside, middle, and outside edge). Three measurements 60° apart must be taken at each location.

3.5.3 Check shoulder to shaft runout for the FE and BE bearings by rotating shaft on true shaft axis with a dial indicator placed against the shoulder. Acceptance Criteria: runout of shoulder must be within 0.0005 inch.

3.5.4 Check bearing seat runout by rotating shaft on true shaft axis with a dial indicator placed against the bearing seat. Acceptance Criteria: Runout must be within 0.0002 inch.

3.5.5 Recondition threads and fit key to keyway. Visually inspect keyway for deformed, cracked or chipped edges or high spots. Verify that fit between key and key-seat sides has a minimum clearance of 0.002 inch or maximum interference of 0.0005 inch. High spots in keyway may be removed by machining or grinding. Do not unnecessarily repair any keyway; instead, use a step key up to a maximum of 0.010 inch oversize and, where possible, include a radius in step. If key tightness cannot be corrected with a step key, re-machine worn/damaged keyways to recommended over-sizes as follows: Maximum of 0.015 inch oversize for a 1/8-inch key and increasing oversize allowance of 0.010 inch for each 1/8-inch increase in key size up to a maximum of 0.075 inch. If key tightness cannot be corrected by keyway repair, replace part involved.

3.5.6 Apply a thin coat of petrolatum to unpainted mating surfaces except for explosion-proof motors that shall have clean, dry mating surfaces.

3.6 Submit one legible copy, in approved transferrable media, of a report listing results of the requirements of 3.2 through 3.5 to the COR. (CDRL A001)

3.7 Rewind the equipment in accordance with Original Equipment Manufacturer (OEM) "for Navy use" winding data.

3.7.1 Do not permanently connect winding until after successful completion of testing of 3.8 through 3.11.

3.7.2 Material shall conform to:

3.7.2.1 Magnet wire, National Electrical Manufacturers Association NEMA MW-1000, Table MW 20 (rectangular wire), or equivalent to OEM original

3.7.2.2 Slot and phase insulation, .015” (minimum) NOMEX, NEMA FI-3-2004 (Formerly MIL-I-24204).

3.7.2.3 Slot wedge-spacers MIL-I-24768/17. Top wedge use GME per MIL-I-15037

3.7.2.4 Lead wire, stranded, MIL-DTL-16878, EPDM 600 Volts 150°C.

3.7.2.5 DACRON TAPE size .005” min thickness. Use TRIMTEX T-7516 or equivalent. Dacron winding coil wrap minimum at least half lap overlap.

(V) CHECK POINT - INSULATION RESISTANCE TEST

3.8 Accomplish 500-volt megger insulation resistance test using Paragraphs 300-3.2.2 through 300-3.2.3, 300-3.4.8, 300-3.4.11, and 300-5.3.7.1 of 2.2 for guidance. Acceptance Criteria: 1000 megohms minimum acceptable.

(V) CHECK POINT -

DC WINIDNG RESISTANCE TEST

3.9 Accomplish a DC resistance test of windings, using a Wheatstone or Kelvin bridge, or with an ohmmeter capable of resolving one milliohm (0.001 ohm). Record phase balance for multi-phase equipment, using Paragraph 5.21 of 2.4 for guidance. Acceptance Criteria: Terminal winding resistance: 0.0097 ohms +/- 10% and the values within each phase must be within 5% of each other per reference 2.5, corrected to 25°C per Enclosure 1 and drawing 88305-51.

(V) CHECK POINT -

VOLTAGE SURGE TEST

3.10 Accomplish a voltage Surge Comparison Test at 2632 (+0/-50) volts indicating no failure of insulation breakdown, shorted turns, phase-to-phase, coil turns or incorrect connections. Refer to Paragraphs 300-3.5.4 through 300-3.4.7 of 2.2 for guidance.

(V) CHECK POINT - DC HI POT TEST

3.11 Accomplish a DC HI POT test at 3000V DC in accordance with Paragraph 300-3.5.2 through 300-3.5.2.3.3 of 2.2 for guidance.

3.12 Permanently connect the windings.

3.12.1 Repeat tests described in 3.8 through 3.11.

(V) CHECK POINT – Winding Phase Rotation

3.12.2 Using a reduced voltage 3-phase supply of known sequence, perform a ball and cage test. Mark the leads for proper rotation if known, and for CCW rotation when viewed from the end opposite the drive if not known.

(V) CHECK POINT - VARNISH TEMPERATURE, VISCOSITY, AND GEL TIME TESTS

3.13 Select the insulation process based on winding insulation classifications and to meet state or local air pollution standards.

NOTE: As an upgrade alternative to Varnish Thermal Class F (155) application, A Vacuum Pressure Impregnated (VPI) process using Epoxylite no. 478 resin, Thermal Class H (180 °C). or RANVAR 5095 Epoxy is acceptable. NAVSEA-certification of repair facility is NOT required. VPI process requires at least minimum of two VPI process on stator rewound windings applications cycle.

3.13.1 Use Thermal Class F (155°C) varnish methods and material, using Paragraphs 300-4.5.8 through 300-4.5.8.9 of 2.2 for guidance

3.13.1.1 Maintain the varnish in accordance with Paragraphs 300-4.5.8.3 through 300-4.5.8.3.3 of 2.2 and the varnish manufacturer's instructions.

3.13.1.2 Maintain a current revision of the varnish manufacturer's instructions on storage, maintenance, and use of the type of varnish to be applied.

3.13.1.3 Maintain a record of varnish temperature, viscosity, and, for solvent-less varnish, gel time tests. Tests must show varnish is within varnish manufacturer's recommendations and have been accomplished in the intervals specified by the varnish manufacturer. The record must also show the varnish is being stored as recommended by the varnish manufacturer.

3.14 Varnish windings in accordance with Paragraphs 300-4.5.8.2 of 2.2 and the varnish manufacturer's instructions.

3.14.1 Do not immerse the leads.

3.14.2 Wipe surfaces that affect assembly such as rabbet fits and mounting flanges with a cloth moistened with a solvent after draining and before baking.

3.14.3 Remove excess varnish runoff from the component locations described in 3.14.2 after final baking. Apply a thin coat of air-dry varnish to metal surfaces exposed by the removal process in accordance with Paragraphs 300- 4.5.8.5 and 300-4.5.8.6 of 2.2.

3.15 Repeat tests described in 3.8 through 3.11 (Megger Insulation, DC Hi-Pot, and Surge test). Record test data.

3.15.1 Accomplish an AC HI POT test at 1880 VAC. in accordance with Paragraphs 300-3.5.3 through 300-3.5.3.2.10 of 2.2 for guidance and record test data.

3.15.2 Accomplish 500-volt megger insulation resistance test. Use Paragraphs 300-3.2.2 through 300-3.2.3, 300-3.4.8, 300-3.4.11, and 300-5.3.7.1 of 2.2 for guidance. 1000 megohms minimum acceptable. Record test data.

3.15.3 Submit one legible copy, in approved transferrable media, of a report listing results of the requirements of 3.8 through 3.11, 3.12.1, 3.12.2 and 3.15 to the COR. (CDRL A001)

3.16 Accomplishment of the balancing requirement for the rotating assembly as detailed below;

3.16.1 Measure and record the maximum eccentricity of the rotor shaft and installed components relative to the points of support using dial indicators.

3.16.2 Dynamically balance rotor assembly components in accordance with 2.6, Paragraph 5.2.2.1 and 5.2.2.2 (Balance limits for rigid rotors).

3.16.3 Submit one legible copy, in approved transferrable media, of an equipment overhaul report to the SUPERVISOR. Report shall include a balance report in accordance with Section 231-8.13 of 2.7 and a baseline (after overhaul) vibration survey report in accordance with NAVSEA Standard Item 009-104 of 2.1. (CDRL A001)

3.17 Install identification markers on wiring in the external connection box.

3.17.1 Markers shall be aluminum wrap-around type with metal stamped or embossed markings.

3.18 Repair scored areas of frame, end bells, and shaft

3.19 Prepare and refinish equipment. Protect machine surfaces, windings, and nameplates from being painted or otherwise damaged.

3.19.1 Accomplish cleaning and painting of housing, fan, and interior and exterior of each end bell in accordance with NAVSEA Standard Item 009-32, Table 5, Line 9.

3.19.2 Lubricate ball bearings and fill endbell cavities

using grease per DOD-G-24508. Install new single shield bearings, size 313 (Type 111, Class 2, per 2.5.

3.19.2.1 Do not over-pack or allow grease to slump into bearing. The grease will bleed into the bearing during normal operation.

3.19.2.2 Pack the outer bearing caps with bearing grease (DOD-G-24508) opposite the seal or shield one-third to one-half full.

3.19.2.2 Ensure grease fitting tubes are cleaned. Pack the tubes (fill in side only) with grease.

3.19.3 Torque bearing locknut to 131 – 175 ft-lbs per 2.4, Table 6-6.

3.20 Assemble the equipment disassembled in 3.2, using 2.2 through 2.5 for guidance.

3.20.1 Torque mounting hardware of end bells, bearing caps to specification per 2.4, Table 11-1.

3.20.2 Install new gaskets inspection plates, access lovers/vents if installed per reference 2.5. Gaskets shall conform to MIL-PRF-1149 unless otherwise specified.

3.20.3 Rotate shaft by hand a minimum of 3 revolutions.

Rotor must rotate freely without sticking, binding, or scraping shall not be allowed.

3.20.3 Measure axial end play using a dial indicator; total axial end play must be greater than 0.030”, per NOTE 7 of Reference 2.5 (DWG 88305-51).

3.20.4 Install label plates conforming to MIL-DTL-15024 for those identified to be missing or damaged.

(V)(G) CHECK POINT - NO-LOAD SHOP TEST

3.21 Accomplish a no-load shop test of the motor for a minimum of four hours.

3.21.1 Verify proper direction of rotation.

3.21.2 Set-up motor on the test stand in a configuration as close as possible to it's true operational configuration (horizontally mounted, vertically mounted, resiliently mounted, etc.).

3.21.3 Refer to 2.5 (Performance at Rated Voltage and Frequency) Table Data for expected electrical zero percent unloaded test value.

Record, every 15 minutes for at least 30 minutes minimum unloaded test; current and voltage in each phase, speed and bearing temperature rise measured on the equipment's exterior near each bearing. Acceptance Criteria: Bearing temperatures shall not exceed 180 degrees Fahrenheit.

3.21.4 Measure and record hot insulation resistances of winding to ground immediately upon completion of the operational shop test, using a 500-volt megger.

3.21.5 Ensure that line frequency does not deviate by more than 5% from rated frequency. Ensure that line voltage does not deviate by more than 10% from rated voltage. Ensure the sum of line frequency deviation and line voltage deviation does not exceed 10%.

3.21.6 Submit one legible copy, in approved transferrable media, of the recorded data to the COR. (CDRL A001)

(V)(G) CHECK POINT – VIBRATION ANALYSIS SHOP TEST

3.21.7 Accomplish sound and vibration analysis.

(V)(G) CHECK POINT – HEAT RUN (Dynamometer) LOADED SHOP TEST

NOTE: Do not exceed nameplate amps heat run. Due to dynamometers torque increment values it is not always possible to operate motor at the exact rated horsepower. Operate motor as close to rated horsepower as attainable.

3.21.8 Operate the motor on the dynamometer at rated horsepower for a minimum of one (1) hour and a maximum of four (4) hours. Acceptance Criteria: Heat run will be complete upon achieving three (3) consecutive bearing and frame temperature readings with temperatures remaining within three (3) degrees centigrade (five degrees Fahrenheit). Refer to 2.5 (Performance at Rated Voltage and Frequency) Table Data for expected electrical full loaded test value.

3.21.9 Accomplish 500-volt megger insulation resistance test. Use Paragraphs 300-3.2.2 through 300-3.2.3, 300-3.4.8, 300-3.4.11, and 300-5.3.7.1 of 2.2 for guidance. Acceptance Criteria: 1000 megohms minimum acceptable Record test data.

3.21.10 Submit one legible copy, in approved transferrable media, of the recorded data to the COR. (CDRL A001)

3.22 Construct and crate the motor for shipping to prevent damage.

3.22.1 Ship motor to Naval Air Station, Coronado California, Attn: Mr. David Fitzpatrick @ Commander Naval Air Forces, Pacific (CNAP) – telephone number 619-545-5021, for USS CALR VINSON (CVN 70).

3.22.2 Provide tracking information for shipment to the COR.

3.22.3 Include a copy of all test and measurement information, crated with the motor, inside a waterproof package.