GE GE752 manual Air Curing Commutator, Basic Overhaul, Testing Before Disassembly

Vertical Drilling Motor, Type GE752, GEK±91584D

WARNING: When using compressed air for	3.	Increase the machine speed to approximately
		900 rpm and blow air on the commutator until the
cleaning purposes, flying debris and particles
		sparking stops.
may present a hazard to personnel in the im-
	4.	Increase the speed until full speed is reached (do
mediate area. Personnel should be provided
with, and trained in the use of, personal pro-		not exceed 1000 rpm) and continue to blow air on
		the commutator until all sparking stops.
tective equipment as specified by applicable
	5.	Stop the machine.
federal or state safety regulations.
	6.	Disconnect external power supply to machine.
Air Curing Commutator
		Make all necessary mechanical and electrical
		changes to restore the machine to service.

After the commutator has been sanded, stoned or ground and blown clean, it should be air cured as fol- lows:

1.Rotate the armature slowly with the same source of power used for sanding, stoning or grinding.

2.Use a rubber air±hose with the nozzle removed and sweep the commutator surface with 70 psi air pressure.

WARNING: Observe all the following safety precautions to avoid injury.

1.Remove all metal fittings from the air hose or, if impossible to remove, insulate the fitting.

2.Be certain an operator is stationed at the power±supply control to quickly remove power from the machine should an emer- gency arise.

3.Wear rubber±insulated gloves and goggles while air curing. Stand on an in- sulated platform.

4.Avoid contact with the cable terminals.

WARNING: Do not come into close proximity of an energized motor during the cleaning pro- cess. The armature commutator and brush rig- ging have a high electrical charge which could cause serious injury or death. Always use a hose tip that is an electrical non±conductor when cleaning with air.

7.Use a clean cloth and wipe off the brushholders, creepage band and accessible surfaces in the commutator chamber.

8.Brushholder Clearance ± Install the brushholder previously removed and check and adjust as re- quired the brushholder±to±commutator clear- ance on all brushholders. See previous Brush- holder Replacement and Brushholder Clearance Adjustment sections for instructions to install the brushholder, and to adjust brushholder clear- ance.

9.Installing Brushes ± Refer to BASIC REPAIRS, Brush Replacement section, and install serviceable or new brushes per instructions listed.

10.Vacuum interior of commutator chamber.

BASIC OVERHAUL

NOTE: Be sure to use the correct drawings for the machine being overhauled. Refer to Table 2 on page 20 to determine the correct drawing.

It is recommended that a basic overhaul be per- formed every two years, or 18,000 hours. The time inter- val between overhauls may vary, depending on the con- dition of the machine and the severity of service.

The following basic overhaul procedures include in- structions to disassemble, clean, inspect, repair, reas- semble and test the machine.

TESTING BEFORE DISASSEMBLY

Perform the following tests prior to disassembly of the machine:

19