Table of Contents APPENDIX B SPECIFICATION FOR GENERATOR OVERHAUL EMD MODEL AR10 D18... B-1 B.01 SCOPE... B-1 B.02 GENERAL... B-1 B.03 ELECTRICAL QUALIFICATION... B-1 B.04 EQUIPMENT RECONDITIONING... B-2 B.05 BEARING BRACKET ASSEMBLY... B-7 B.06 RECTIFIER ASSEMBLIES... B-8 B.07 RECTIFIER ASSEMBLY HOUSING... B-8 B.08 SLIP RING ASSEMBLY... B-9 B.09 AR10 FINAL ASSEMBLY... B-9 i
APPENDIX B SPECIFICATION FOR GENERATOR OVERHAUL EMD MODEL AR10 D18 B.01 SCOPE A. This Specification covers the scope of work and material requirements for overhauling AR10-D14 and AR10-CA5 main generators. B. As part of the overhaul all D14 companion alternators shall be replaced with CA5 alternators which have either been overhauled in accordance with this specification or are new. CAUTION: D14 rotors must never be installed in CA5 stators under any circumstances, and vice versa. B.02 GENERAL A. The level of inspection and test values shown in this specification are only the minimum requirements for performing the basic overhaul. B. The main generator must conform to the following standards and specifications as outlined. C. The rehabilitation shall be in accordance with the specifications of the original equipment manufacturer. D. All component parts shall be OEM approved. E. All consumables such as gaskets, seals, nuts, bolts, etc. shall be replaced with new OEM approved materials. F. Clean all machined fits to bare metal. G. Check and close all threaded holes and dimensional tolerances to comply with M.I. 3317-1. H. Check for loose coil wedges. I. Heat shrink material is to be applied to extend 1/2" over insulation and cover crimp of non-insulated lugs. J. Apply clear heat shrink over newly applied wire markers. K. Apply Loctite in all threaded fastener applications. L. External jumpers and leads which are not acceptable for continued service shall be replaced with Exane insulated wire or cable. B.03 ELECTRICAL QUALIFICATION A. Thoroughly clean stator and rotor, including slots, and bake dry. B. Perform the following electrical tests: 1. AR10 Stator:
Megger Surge Comparison High Pot 500 VDC 2000 Volts per phase 3000 VDC 100 Megohm minimum for one (1) minute 50 microamp maximum for one (1) minute 2. CA5 Stator: Megger 1000 VDC 200 Megohm minimum Surge Comparison 9000 Volts per phase 3. AR10 Rotor: Megger Impedance Power Consumption Per Coil High Pot Surge Comparison Test 500 VDC 110 VAC 110 VAC 3000VDC 1000 Volts 100 Megohm minimum for one (1) minute Equal voltage drop per coil+/- 10% between coils 6-8 Amp nominal, equal Watts per coil +/- 30% between coils 50 microamp maximum for one (1) minute 4. CA5 Rotor: Megger 1000 VDC 500 Megohm minimum Impedance 110 VAC Equal voltage drop per coil Power Consumption Per Coil 110 VAC 6-8 Amp nominal Surge Comparison Test 1000 Volts B.04 EQUIPMENT RECONDITIONING A. AR10 Stator 1. Check for and repair mechanical deficiencies: a. Loose coil wedges b. Defective insulation c. Bracing blocks d. Loose cabling 2. Inspect for stator surge rings and notify the Authority if not applied.
3. Replace loose wedges. 4. Replace damaged insulating materials, boots, sleeves, etc. 5. Tie and insulate loose cables. 6. Apply bracing blocks in upper and lower diamond section between adjacent coils at each end of coil. 7. Dip in OEM approved varnish and bake at 300 o F for 12 hours. 8. Paint with red air dry enamel. 9. Clean all electrical surfaces. B. AR10 Stator Rewind (If Required) 1. Remove old coils using cold stripping methods. 2. Clean and inspect all slots and laminations. 3. Rewind stator using all new windings and cables. 4. Use all new hardware. 5. Install new surge rings. 6. Apply bracing blocks in upper and lower diamond sections between adjacent coils at each end. 7. Vacuum pressure impregnate and bake in OEM approved varnish. 8. Dip in class H varnish and bake for one (1) minute. 9. Electrical tests: Insulation resistance 500 VDC 200 Megohms minimum for one (1) minute Surge comparison Hi-Pot 9000 VDC per phase 3700 VAC or 5200 VDC 50 Microamps maximum for one (1) minute C. Final AR10 Stator 1. Inspect and qualify the eight lifting-eye bolt holes. a. If threads are unacceptable, repair as follows: i. Drill old hole oversize. ii. Weld repair hole.
iii. Drill new hole and tap using proper template. 2. Weld all dowel holes in mounting feet (if necessary). a. Resurface mounting feet, as required. 3. Inspect auxiliary generator mounting pads and repair or replace as necessary to new condition. 4. Repair any damaged sheet metal on the frame. 5. Clean all machined surfaces. D. AR10 Rotor 1. Thoroughly clean and bake dry. 2. Replace all coils 3. Inspect coil wedges. 4. Check for mechanical defects. 5. Dimensionally check shaft and rotor to assure they are within OEM tolerances. 6. Remove series connection bus bars. 7. Remove all series connection insulating block assemblies. 8. Clean bus bars and apply new insulating sleeves. 9. Electrical tests: Insulation resistance 500 VDC 250 Megohms minimum Surge comparison High-Pot 2800 VDC 2000 VRMS 30 Microamps maximum after 1 minute E. Rotor reconditioning 1. Replace coils as follows: a. Apply coils with new bolts and washers. b. Apply thread lubricant to bolts. c. Torque bolts to 1,050 foot pounds. i. Torque inside field pole bolts first, then outside bolts. d. Loosen bolts to 500 foot pounds.
e. Re-torque bolts to 1,050 foot pounds. i. Torque inside field pole bolts first, then outside bolts. f. Apply coil wedges and secure wedge bolts. g. Apply reconditioned series connection insulating blocks with sheet of Class H insulation below the block. h. Apply reconditioned or new bus bars. F. Rewind AR10 (if required) 1. Strip completely. 2. Modify pole pieces to bracing wedge blocks as required. 3. Rewind field poles per OEM specification. 4. Apply coils as per Part B.04E.1. G. Final AR10 Rotor 1. Paint complete rotor assembly with red insulating varnish and bake. 2. Vacuum pressure impregnate complete assembly in Class H varnish and bake. 3. Replace rotor cable assembly with new. 4. Install new terminal lugs. 5. Electrical test as follows: Insulation resistance: Impedance: Power consumption: High-Pot: Surge Comparison Test: 500 VDC 110 VAC 110 VAC 3000 VDC 100 Megohm minimum for one (1) minute Equal voltage drop per coil +/- 10% between coils Equal watts per coil +/- 30% between coils 50 Microamp maximum for one(1) minute 2000 Volts H. CA5 Stator 1. Check for mechanical deficiencies: a. Loose coil wedges. b. Defective insulation.
c. Damaged or loose bracing blocks. d. Loose cabling. 2. Replace loose wedges. 3. Replace damaged insulating materials, blocks, boots, sleeves, etc. 4. Tie and insulate loose cables. 5. Dip in OEM approved varnish and bake at 300 F for 12 hours. 6. Paint with red air-dry enamel. 7. Clean all electrical connection surfaces. I. CA5 Rotor 1. Replace all coils. 2. Inspect and install series connection bus bars. 3. Torque all pole pieces to OEM specified values. 4. Check for fretting between pole pieces. 5. Renew any pole studs that are damaged or broken. 6. Torque rotor pole assembly to OEM specified values. 7. Check poles for spacing and parallelism. 8. Paint with red air drying enamel. 9. Dip with Class H varnish and bake. 10. Renew cable assembly and secure with new sleeving and polyester binding. 11. Install new terminal lugs. 12. Electrical test as follows: a. Insulation resistance 1000 VDC 500 Megohms minimum b. Impedance 110 VAC Equal voltage drop per coil c. Power consumption 110 VAC 6-8 Amp nominal per coil d. High-pot 3000 VDC 50 Microamp maximum after 1 minute
B.05 BEARING BRACKET ASSEMBLY A. AR10 Bearing Bracket 1. Clean thoroughly and inspect. 2. Remove grade markings and old thrust dimensions. 3. Remove old paint and repair any holes as necessary. 4. Paint with red electrical enamel and bake. B. Bearing 1. Renew bearing. 2. Renew bearing liner. 3. Renew bearing sides. 4. Pack bearing with Exxon Unirex N-2 grease. 5. Verify dimensional tolerances on bearing housing bore are within OEM specified values in accordance with EMD M.I.s 3322-4 and 3322-5. 6. Chase all threads and repair as necessary. 7. Paint all non-machined surfaces with red air-dry enamel. 8. Re-assemble with new insulation and grade 8 bolts. a. Torque bolts to OEM specifications. 9. Perform electrical tests as follows: a. Insulation resistance 500 VDC 250 Megohm minimum b. High-Pot 500 VRMS 10 Microamps maximum
B.06 RECTIFIER ASSEMBLIES A. After removal and disassembly, clean and dry all components except fuses and inspect. B. Install all new fuses and indicators. C. Threaded inserts may be repaired using epoxy. D. Apply red insulating enamel and bake side plates, center plates, and end blocks of fabricated assembly. E. Remove all carbon and corrosion from diode connecting bars. F. Install new diode heat sink. G. Replace all diodes with new EMD 40029131 and 40029132. H. Nickel plate bus bars and bus fuse bars. I. Assemble diodes in heat sink per OEM instructions. J. Install new insulating sleeves on the four hexagon connection bars that are adjacent to and under the positive and negative bus bars. K. Finish assembly per OEM instructions. B.07 RECTIFIER ASSEMBLY HOUSING A. Recondition suppression system, installing new clamps, capacitors, resistors and circuit wiring. 1. Wire shall be Exane. 2. Capacitors shall be non-pcb type. 3. Wires shall be properly identified and marked. B. Replace current transformers with new. 1. Test polarity before installing. 2. Current transformer leads are to exit air box at approximately 8 o'clock with leads extended 36" beyond the housing.
C. Install new insulated clamping blocks. D. Clean or replace all safety glass as necessary. E. Clean and repair snow guard and paint with red air dry enamel. F. Install new air box gaskets. G. Clean bus bar and refinish, if necessary. B.08 SLIP RING ASSEMBLY A. Recondition slip rings. 1. Check bore and outside dimensions per OEM specifications for condemning limits. 2. Rings are to be turned and polished. 3. Check rings for cracks, concentricity and pitting. a. Maximum allowable runout is 0.005". B. Remachine spiral groove, if not present. C. Clean and qualify brush holders. 1. Verify proper spring tension. 2. Renew brushes. 3. Apply new brush post insulators. B.09 AR10 FINAL ASSEMBLY A. All exterior windings shall be checked for continuity, grounds and high voltage breakdown using a minimum of 2000 VDC to confirm isolation from the frame. B. Clean exterior and prepare surface. 1. Paint exterior with suede gray paint. C. Remanufacturer's plate shall be riveted to the AR10 frame above OEM nameplate. 1. Plate must include remanufacturer s name, date of remanufacture, and remanufacturer s part number, if different. D. Apply blueing to exposed unpainted surfaces to prevent corrosion.