TM- 9-4910-663-34
Table 2-5. TROUBLESHOOTING (Continued)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
If coil resistance is not within specified limits, replace relay K5.
Step 6. Reconnect lead disconnected in step 5. With circuit breaker switch CB1 set to OFF position, check
for continuity across appropriate terminals (fig 2-4) of POLARITY REVERSING switch S7 with switch
set to NEG GND position.
Replace switch S7 if open indication is obtained.
6. LOAD BAND CIRCUIT
a. LOAD BANK CIRCUIT INOPERATIVE OR OPERATES ERRATICALLY DURING TESTING OF EXTERNAL
COMPONENTS.
Step 1. Set all LOAD SELECTION switches to OFF position. Set DC AMMETER LOAD & STARTER
OUTPUT CURRENT BATTERY CHARGE CURRENT RANGE switch S14 to LOAD X1 position.
Connect ohmmeter between REGULATOR B± and REGULATOR B-binding posts. Check to see that
circuit breaker switch CB1, CIRCUIT BREAKERS CB2 DRIVE CONTROL circuit breaker, and
CIRCUIT BREAKERS CB5 RELAY CONTROL circuit breaker are all set to ON position. Set
MASTER LOAD DISCONNECT switch S8 and LOAD SELECTION 0-25 AMPS/0-12.5 AMPS switch
S24 to ON position. Check ohmmeter indication as VARIABLE LOAD control R32 is rotated from fully
counterclockwise setting to fully clockwise setting. Resistance should vary between 46.1 ohms ±5%
and 1.14 ohms ±5%.
If ohmmeter indicates open circuit, proceed to step 2; if indication is normal, proceed directly to step
9.
Step 2. Using ohmmeter, check for 1.14 ohm ±5% indication between REGULATOR B-binding post and load
bank terminal 19.
If resistance is not as specified, replace load bank element.
Step 3. Using ohmmeter, check resistance between center terminal of rheostat R32 and terminal with lead.
Resistance should be variable between 0 and 45 ohms.
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