NOTE

ARMY TM 9-6115-464-34 AIR FORCE TO 35C2-3-445-2 NAVY NAVFAC P-8-624-34 CAUTION Rheostat must be set in maximum resistance position to protect the ammeter in the event the field circuit is short circuited. Failure to observe this caution could result in equipment damage. (a) Install alternator in test circuit as shown in figure 3-13. (b) Slowly reduce field rheostat resistance while observing ammeter and voltmeter. (c) When field rheostat reaches zero ohms, ammeter should indicate 3.0 to 3.5 amperes with voltmeter indicating 24 Vdc. (d) If current is not as specified, check for poor connections and inadequate brush contact. (9) Conduct alternator output and voltage protector test as follows: (a) (b) (c) (d) (e) (f) (g) (h) (i) Install alternator in test circuit shown in figure 3-14. NOTE If alternator is not installed on generator set for this test, a means of rotating the alternator at 2,000 to 3,000 RPM must be provided. Adjust the drive device to provide 2500 RPM. Note the voltmeter indication. Nominal voltage should be 28 Vdc ± 0.3 Vdc. If voltage is not as specified, adjust the voltage regulator rheostat on the alternator rear cover. Close switch (S2) to put carbon pile load on the batteries. Check ammeter and voltmeter indications. Nominal current output should be 20-25 amperes with charging voltage exceeding 25.0 Vdc. CAUTION Open switch (S2) immediately after current test to avoid discharging the batteries. If nominal voltage cannot be obtained, disassemble alternator and correct difficulty. Remove alternator from test circuit, remove rear cover assembly and disconnect test leads. Reinstall rear cover assembly and fuse. f. Installation. Refer to Operator and Unit Maintenance Manual for battery charging alternator installation instructions. 3-28