Vertical Drilling Motor, Type GE752, GEK±91584D
Flood Dipping Coiled Frame
After field coils have been repaired or replaced and electrical tests completed, insulate the coiled frame by flood dipping in GE±8001 varnish. See Table 4, Page 55, for varnish viscosity limits.
Varnish may be thinned, as necessary, with Solves- so* No. 100 thinner. Agitate varnish for 15 minutes be- fore dipping frame.
1.Be sure all coil connections are made and insu- lated, and all cables and ties for cables and con- nection straps are in place. Tie cable ends above the varnish level.
2.Coat all machine±fit surfaces with GE±271 black varnish or stripping compound and plug bolt holes with dummy bolts.
3.Heat the coiled frame to 40±80 C (104±176 F) and dip the frame drive end down (with all coil connections covered) for at least 15 seconds. Drain and remove the frame from the varnish. Al- low the frame to drain for at least 5 minutes in a vertical position, drive end down.
4.Bake the frame in a pre±heated oven at 150 C (302 F) for 30 minutes, minimum.
5.Clean the varnish from machined surfaces and unplug the tapped holes.
TEST AFTER REPAIR
(Coiled Frame Without Armature)
1.Pass 24.0 amperes(60 Hz current) through the exciting (series) field and read the voltage drop.
Minimum Volts | 13.1 |
Maximum Volts . . . . . . . . . . . . . . . . . . . . . . 15.6
2.Pass 24.0 amperes (60 Hz current) through the commutating (CP) field and read the voltage drop.
For Non±Magnetic retainers:
*Standard Oil Co. of Pa.
TABLE 4
VARNISH VISCOSITY CHART FOR
DIPPING COILED FRAME
NOTE: When necessary, use Solvesso No. 100 to thin var- nish.
GE NO. 8001 VARNISH
NO. 3 ZAHN CUP
| 70 |
|
|
|
|
|
|
| 60 |
|
|
|
|
|
|
| 50 |
|
|
|
|
|
|
TIME ± SECONDS | 40 |
|
|
|
|
|
|
30 |
|
|
|
|
|
| |
|
|
|
|
|
|
| |
| 20 |
|
|
|
|
|
|
| 10 |
|
|
|
|
|
|
| 0 | 10 | 20 | 30 | 40 | 50 | 60 |
| 0 |
TEMP. DEGREES C
FIG. 33. FIELD COIL POLARITY CHECK. E±888A.
55
