Table 1-3.—Open or Shorted Rotor

1-57 The angles shown in these tables do not apply to systems using differentials, or to systems whose units are incorrectly zeroed. Table 1-2.—General Symptoms Preliminary Actions: Be sure TR is not jammed physically. Turn TX slowly in one direction and observe TR. SYMPTOMS TROUBLE Overload Indicator lights Units hum at all TX settings One unit overheats TR follows smoothly but reads wrong Rotor circuit open or shorted. See table 1-3. Overload Indicator lights Units hum at all except two opposite TX settings Both units overheat TR stays on one reading half the time, then swings abruptly to the opposite one. TR may oscillate or spin. Stator circuit shorted. See table 1-4. Overload Indicator lights Units hum on two opposite TX settings Both units get warm TR turns smoothly on one direction, then reverses Stator circuit open. See table 1-5. TR reads wrong or turns backward, follows TX smoothly Unit interconnections wrong. Unit not zeroed. See tables 1-6 and 1-7. Table 1-3.—Open or Shorted Rotor Preliminary Action: Set TX to 0° and turn rotor smoothly counterclockwise. SYMPTOMS TROUBLE TR turns counterclockwise from 0º in a jerky or erratic manner, and gets hot. TX rotor open TR turns counterclockwise from 0º or 180º in a jerky or erratic manner. TX gets hot. TR rotor open TR turns counterclockwise from 90º or 270º, torque is about normal, motor gets hot, and TX fuses blow. TX rotor shorted TR turns counterclockwise from 90° or 270°, torque is about normal, TX gets hot, and TR fuses blow. TR rotor shorted