Exide Technologies Section 93.20 - Manual (Page 10)

6
SECTION III
TROUBLESHOOTING
1. CAUTION NOTICE
Before troubleshooting, always isolate and de-energize the charger by opening the AC circuit breaker
(CB1) and the DC circuit breaker (CB2). This avoids the possibility of high short circuit current damaging
the charger, tools, test equipment, or injuring personnel. NOTE: Circuit breaker terminals (CBx), printed
circuit boards (Ax) and terminals/terminal blocks (TB1, TB2, TB3, TB5 & TB15) have dangerous voltage
across them, even when both circuit breakers are open. After isolating the charger, check that the voltage
across the filter capacitors (C1/C2) is zero. Once charged, they will take several minutes to discharge if
bleeder resistor (R1) is open. If DC circuit breaker (CB2) is not provided, remove the DC fuses (F1/F2) in
order to isolate the charger from the battery. AFTER LOCATING THE CHARGER PROBLEM, ALWAYS
DE-ENERGIZE ALL AC AND DC CHARGER INPUTS AT THE POWER SOURCE BEFORE
SERVICING.
2. TROUBLESHOOTING PROCEDURE
a. When a charger is not operating properly, the cause must be determined by checking various
components until the fault is located.
b. The major components are not checked in the order as listed in Section II, 9, since a charger may
exhibit a number of difficulties, each with different symptoms. In many cases, failure of one component may
cause another component or part to fail. Therefore, the following paragraphs treat major components,
functional circuits and parts individually (or by symptom). Together with serviceability measurements and
tests, the faulty part or component should be located.
c. Most of the following checks can be performed with an oscilloscope, a VoltOhmmeter (similar to a
Simpson Model 260) and an SCR tester.
d. Consult the trouble-shooting chart in Table A on page 27. When using the table, first locate the fault
symptom observed (in the left hand column) then follow the sequence for checking components in the
numerical order listed (1, 2, 3 etc.) for that particular symptom. Follow this sequence until the trouble is
located. After correcting the trouble, check the charger for normal performance as described in Section II, 8.
e. In addition to those symptoms listed in Table A, the following procedure should be followed for any
condition:
•
Check voltage of the AC supply to insure that it is within 10% of the value of the
specified input voltage.
•
Examine charger for any evident loose or improper connections, particularly at the
control unit, transformer (T1), input and output terminal board.
•
Check continuity of battery circuit by comparing voltage at charger terminals with
total of cell voltages.
•
Check accuracy of voltmeter and ammeter on the charger.
3. TESTING OF COMPONENTS
a. External Circuit Wiring
1. When no line voltage exists between TB1-L1 and TB1-L2, check the AC line back to source.
2. With no output, or a low output, the external DC wiring may be at fault. Check the wiring between
charger and battery to see that it is properly installed. Make certain that terminals are tight and clean, and
that the DC wiring is free from grounds. The total operating voltage drop in the loop or leads between the
charger and battery terminals should never exceed 0.5 volt (at rated charge current), and preferably should
be kept considerably below this limit by using a sufficiently large wire size.