TROUBLESHOOTING (Continued)

TM- 9-4910-663-34 Table 2-5. TROUBLESHOOTING (Continued) MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION If single-phasing is noted, replace drive starter MS1. Step 10. Set circuit breaker switch CB1 to OFF position. Remove links from terminals 1 through 9 of link board assembly. Using ohmmeter, check for 0.3 to 0.4 ohm resistance indication between terminals 1 and 4, 1 and 9, 2 and 5, 2 and 7, 3 and 6, and 3-8 of link board assembly. If open indication is obtained between any specified pair of terminals, replace varidrive motor. Step 11. Reconnect links removed in step 10. Set circuit breaker switch CB1 to ON position. Press START switch S3, and check for tripping of overloads OL1, OL2, OL3 of drive starter MS1. Replace varidrive motor if overloads trip repeatedly. d. WHEN START SWITCH S3 IS PRESSED, VARIDRIVE STARTS MOMENTARILY, BUT THEN STOPS. Step 1. Check to make sure that CIRCUIT BREAKERS CB3 BLOWERS and CIRCUIT BREAKERS CB4 BLOWERS circuit breakers are set to ON position. Set circuit breakers to ON position. Step 2. Set circuit breaker switch CB1 to OFF position, and check to make sure that cooling air ducts are not obstructed. Clear away any obstruction. Step 3. With circuit breaker switch CB1 set to OFF position, inspect air flow switch (fig 2-10) visually. Replace air flow switch if it is broken. Step 4. With circuit breaker switch CB1 set to OFF position, disconnect lead from one terminal of CIRCUIT BREAKERS CB3 BLOWERS and CIRCUIT BREAKERS CB4 BLOWERS circuit breakers. Using ohmmeter, check for continuity across terminals of -each circuit breaker with circuit breaker set to ON position. 2-19