ARMY TM 9-6115-644-24
AIR FORCE TO 35C2-3-446-12
MARINE CORPS TM 09249A/09246A-24/2
Connect resistance bridge, between two exalter rotor leads and note resistance reading. Continue this proce-
dure until readings are noted for each combination of leads (i.e., 1 and 2, 1 and 3, and 2 and 3).
TABLE 4-3. Generator Resistance Values At 25°C (77°F)
Component
Resistance
MEP-805A
MEP-815A
Exalter Stator
Between 24.85 & 33.61 ohms
Between 24.9693 & 33.7819 ohms
Exalter Rotor
Between 0.202 & 0.274 ohms
Between 0.2061 & 0.2787 ohms
Generator Rotor
Between 1.03 & 1.51 ohms
Between 1.9874 & 2.6888 ohms
Generator Stator
Between 0.0736 & 0.0994 ohms
Between 0.0306 & 0.0412 ohms
NOTE
Ambient temperature must be expressed in °C. To convert °C to °F use: °F = °C x
9 ÷ 5 + 32
1) To determine the resistance values at current ambient temperature, use the following formula:
R1 = R25 [1 + 0.00385 (T-25)]
Where:
R1
= Unknown resistance
R 25 =
Known resistance at 25°C (77° F)
T
= Current ambient temperature
2) Example for exalter stator leads at 5°C (41 “F):
R1
= 29.23 [1 + 0.00385 (5-25)]
R1
= 29.23 [1 + 0.00385 (-20)]
R1
= 29.23 [1 + -0.077)]
R1
= 29.23 [0.923]
R1
= 26.98 ± 15% ohms
g.
h.
i.
j.
k
1.
m.
Resistance readings should be as shown in TABLE 4-3 for each combination of leads. Readings other than in
TABLE 4-3, indicate open or shorted windings and exalter rotor must be replaced.
Set multimeter for ohms and connect between each exalter rotor lead and end bell in turn.
Multimeter reading of less than infinity indicates defective ground insulation and exalter rotor must be replaced.
Connect exalter rotor leads to rotating rectifier with Iockwashers (4, FIGURE 4-12 ) and bolts (3). Remove tags.
Install end bell top cover and louvered covers, paragraph 4-19-2, step f.
Install generator set housing rear panel, paragraph 2-18-4.
Connect negative battery cable and dose battery access door.
4-41
