GE manual Testing Shunt Machines Models 5GE752UP and US, Motor Operation, Unventilated

Page 68

GEK±91584D, Vertical Drilling Motor, Type GE752

ing caps. Thermometers should contact the bearing caps for best results.

2.Seat the brushes and run for ten minutes at 900 rpm.

Frame temperature should not exceed 25 C rise.

3.With machine running up to speed, measure vi- bration. Vibration should not exceed 0.002 on commutator end. If vibration exceeds this amount, rebalance the armature.

4.Check the commutator for roughness and make sure the brushes are riding properly.

5.Use a listening rod to check for noisy bearings.

6.Stop the machine and mount an indicator on the frame. While turning the armature by hand, mea- sure commutator runout. It should not exceed 0.001 in.

7.Measure field impedance. With 60 Hz a±c and 24 amperes through each field, measure the volt- age drop across total exciting and commutating fields. See the DATA section for voltage limits.

8.Apply a high±potential test to the windings of the assembled machine, as specified in the DATA section.

WARNING: Electric shock can cause serious or fatal injury. Proper precautions should be taken and observed by personnel performing testing to avoid such injury.

TESTING SHUNT MACHINES (Models 5GE752UP and US)

After the motor has been reconditioned and reas- sembled for service, make the following tests to be sure it will operate satisfactorily.

Connect the motor to a d±c welding generator. Refer to connection diagrams (Figs. 21 and 23) for connec-

*Product of Johns Manville Co.

tions. Run the machine by separately exciting the shunt field from a 125 vdc source. From another source of power, apply voltage to the armature circuit until the de- sired speed is obtained.

Motor Operation

Ventilated (2300 cfm at 7.6 in. H2O at Commutator Chamber)

Hold separate field excitation at 50.5 amperes. Vary the armature voltage to obtain the required rpm. At ap- proximately 700 terminal volts (no load), the speed will be 900 rpm.

Unventilated

Hold the separate field excitation at 10 to 15 am- peres. Vary the armature voltage to obtain the required rpm. At approximately 338 terminal volts (no load), the speed will be 900 rpm.

1.Run the motor for five minutes at 450 rpm. In- crease the speed to 900 rpm and run for two hours. Bearing temperatures should not exceed 70￿ C (158￿ F). Run until the bearing tempera- ture remains constant for 30 minutes. Increase the speed to 1300 rpm and hold it while perform- ing Steps 2, 3 and 4. Then shut down the motor. Do not exceed 1300 rpm.

2.Measure vibration when running the motor up to speed. Vibration should not exceed 0.004 in. If excessive, rebalance the armature.

3.Check the commutator for roughness. Be sure brushes are riding properly.

4.Listen for noisy bearings with a listening rod.

5.Stop the motor and mount an indicator on the frame. Turn the armature by hand and measure commutator runout. Runout should not exceed 0.001 in.

6.Measure the insulation resistance of the wind- ings with a megohmmeter. If the resistance mea- sures not less than one megohm, apply an a±c high±potential test to ground for one minute as outlined in the DATA section.

68

Page 67 Page 69
Image 68
Page 67 Page 69
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
Top Page Image Contents