GE Comprehensive Guide to 752 Traction Motor Maintenance and Operation

Page 44

GEK±91584D, Vertical Drilling Motor, Type GE752

edges of the bars. See Fig. 12 for an illustration of the tool. Another method of removing copper fins is to rake the slots with a piece of fiberboard approximately 0.045 in. thick.

2.After slots have been raked with fiberboard or a raking tool, sand the commutator with fine sand- paper to remove small pieces of copper sticking from edges of slots.

3.Thoroughly clean the armature core and com- mutator with dry, compressed air to remove cop- per and dust.

1.If the commutator is discolored or smudged, pol- ishing with canvas, crocus cloth, fine (4/0) sand- paper or 400A Triemite paper is usually suffi- cient.

Abrasive paper should be mounted on a wooden block curved to fit the surface of the commutator.

Used Armature

Apply a high±potential test voltage of 2000 volts, 60 Hz for one minute.

Rewound Armature

Apply a high±potential test voltage of 3500 volts, 60 Hz for one minute.

NOTE: Measure leakage current to ground dur- ing test 3±85.0 milliamps.

WARNING: Electric shock can cause serious or fatal injury. To avoid such injury, personnel should take and observe proper precautions during the high±potential testing.

Resistance Measurement

Refer to the DATA section for armature the resis-

2.Blow loose material off the commutator with dry, compressed air.

3.Check commutator concentricity with a dial indi- cator. Refer to the DATA section for runout limits.

4.Cover the commutator with heavy paper or felt to protect it from damage.

WARNING: Personal injury may result if prop- er eye protection is not worn when cleaning with compressed air.

CAUTION: Never use an emery cloth on this or any commutator. The abrasive particles on emery cloth scratch the commutator surface and lodge in the grooves between commuta- tor segments. This condition creates the pos- sibility of an eventual flashover which could seriously damage the machine.

TEST AFTER REPAIR (Armature)

High Potential Test

Apply test voltage between the commutator (with all segments shorted) and the shaft.

tance value and measure armature resistance.

NOTE: Insulation Processing (Armature VPI)

After the armature has been cleaned and re- paired or rewound, it must be vacuum pressure impregnated. See the Varnish Treatment, ªVac- uum Pressure Impregnationº section for fur- ther required processing of the armature.

A. MICA PROPERLY UNDERCUT.

B. UNDERCUTTING TOOL TOO NARROW, LEAVING FIN AT ONE SIDE OF SLOT.

C. UNDERCUTTING TOOL VERY NARROW, LEAVING FINS AT BOTH SIDES OF SLOT.

D. SLOT IMPROPERLY INDEXED, PART OF BAR CUT AWAY AND FIN OF MICA LEFT.

E. TOOL TOO WIDE, PART OF BAR CUT AWAY.

F.UNDERCUTTING TOO SHALLOW, SERVICE LIFE SHORTENS BEFORE NEXT UNDERCUTTING.

G.UNDERCUTTING TOO DEEP, POCKET COLLECTS CARBON AND COPPER DUST, SHORT CIRCUITING BARS.

FIG. 28. COMMON MISTAKES IN UNDERCUTTING COMMUTATOR SLOTS. E±5024A.

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Contents Contents Vertical Drilling Motor Type GE752GEK±91584D, Vertical Drilling Motor, Type GE752 General DescriptionIntroduction Vertical Drilling Motor, Type GE752, GEK±91584D Model DifferencesContd Model Differences DataData Contd Carbon BrushesPole Bore Diameter measured at center of pole Motors Min Max Motor Ratings Continuous Max. HP Shunt UP Special Tools Equipment Grounding InstructionsGrounding Procedures Fig OverhaulLubrication Grease Tubes and Pipe PlugsBrushholders Fig Inspection MonthlyCovers, Seals, Latches Brushholder Sleeves Brush Spring PressureBrushes CommutatorCreepage Band Flash RingSEMI±ANNUALLY Basic Repairs Brush ReplacementBrushholder Replacement Commutator Resurfacing InstallationBrushholder Clearance Adjustment Sanding Procedure Hand Stoning ProcedureGrinder Installation Fixture GrindingCommutator GRINDER. E±18249 Grinding ±19771ABasic Overhaul Testing Before DisassemblyAir Curing Commutator Disassembly Megohmmeter TestBar±To±Bar Resistance Test Armature Removal From FrameCOMMUTATOR±END Bearing Pilot Longitudinal D732922 CHG. N. E±28621D Models See , Description Puller Tools 41D731569 CHG . E±14383C Puller TOOLS. E±18155A Models US1, AUT Longitudinal D735357, CHG. A. E±37949B Models See Table Cleaning Steam CleaningVapor Degreasing Anti±Friction Bearings/Shaft Tapers/Bearing FitsBearing Inspection ArmatureMotor Frame CommutatorArmature Shaft Inspection Armature Insulation 41D731545 CHG. F. E±18156A See Note Brushholders Lubrication of BoltsConnection Diagram 493A210 CHG . E±39092B Creepage Band Replacement Rewinding ArmatureRiser Width DiameterProcedure Commutator TighteningHydraulic Press Preferred Method Torque Wrench Acceptable MethodSpin Seasoning Commutator Assembled On Armature Commutator ResurfacingTurning To Change Motor DirectionConnection Diagram 41A330278, CHG . E±38055B Connection Diagram 41A330179, CHG. A. E±37950A Raking ±4270BResistance Measurement Test After Repair Armature High Potential TestUsed Armature Rewound ArmatureReplacement Coil InstallationProcedure for New Coil±Pole Assembly Motor Frame Field CoilCoiled Frame Assembly 41D732353 CHG. N. E±39094A Models See , Coiled Frame Assembly 41D732345 CHG. V. E±39095A BOX Ground A1 and A2 View AT E Cables with P65 Coiled Frame Assembly 41D735440, CHG. A. E±38056B Description Magnet Frame Coiled Frame Assembly 41D735343, CHG. C. E±37951C Hardened Washer 1 1/4 Brazing Coil Terminals Gas Torch BrazingCoiled Frame Without Armature Flood Dipping Coiled FrameTest After Repair Varnish Treatment Armature ReassemblyBalancing Armature Armature Bearings Drive±End Bearing Figs , 35, 36Commutator±End Bearing All Models Except US2, UP6, AUT2 and AUP5DRIVE±END Bearing ASSEMBLY. E±18166E DRIVE±END Bearing ASSEMBLY. E±39301 Models US2, UP6, AUT2 and AUP5DRIVE±END Bearing Assembly 41B537821, CHG. B. E±37952B Armature Assembly Into Frame Models UP and AUPCOMMUTATOR±END Bearing Assembly 41B532745 CHG. F. E±39090A COMMUTATOR-END Bearing Assembly 41B538068 CHG . E-39300 Checking Internal Clearance Brush Installation Hub Mounting HUB MountingHub Fitting Models 5GE752AUP, AUT Testing After OverhaulTesting Series Machines Testing Shunt Machines Models 5GE752UP and US Motor OperationVentilated 2300 cfm at 7.6 in. H2O at Commutator Chamber UnventilatedCleaning and Slushing Removing Armature Locking ArrangementLocking the Armature For Shipment ShippingSkidding ProtectionArmatures Preparation of BOXBoxing the Armature Storage Placing Into StorageRemoving from Storage Shipping BOX with Armature Less COVER. E±3784Vertical Drilling Motor, Type GE752, GEK±91584D OUTLINE, UP and AUP 41E903631 CHG. H. E±28755B Hole Grease Vent Tube Grease Tube Holes REF OUTLINE, US1, AUT 41E903745, CHG. A. E±37954B ºDº ºBº Vertical Drilling Motor, Type GE752, GEK±91584D GE Transportation Systems