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35827_A
10. CAPACITOR
TESTING
The purpose of this test is to prove if the capacitor is good, or has failed ‘open’ or ‘shorted’.
The
capacitor
in this charger is a tuning device that maximizes the current output of the
transformer. Failure of the capacitor will decrease the DC current output of the transformer
from 20+ amperes maximum to zero amperes.
CAUTION: DISCONNECT BOTH AC INPUT AND DC OUTPUT CORDS FROM ALL
POWER SOURCES. POWER IS NOT NEEDED FOR THIS TEST.
Remove the Phillips screws that retain the cover, then remove the cover and locate the
capacitor at the rear of the case assembly as shown in Figure 10A.
DANGER: RISK OF ELECTRIC SHOCK! HIGH VOLTAGE! THE VOLTAGE AT THE
CAPACITOR TERMINALS CAN BE AS HIGH AS 660 VOLTS WHILE THE CHARGER
OPERATES. USE EXTREME CAUTION WHEN NEAR THE CAPACITOR TERMINALS.
WARNING: THE CAPACITOR STORES AN ELECTRICAL CHARGE AND MAY NOT BE
FULLY DISCHARGED! TO AVOID AN ELECTRICAL SHOCK FROM THE CAPACITOR
YOU MUST DISCHARGE IT COMPLETELY.
Figure
10A
Discharge the capacitor by adjusting your test meter to its highest DC voltage scale and then
touch and hold the test leads to the capacitor terminals for three seconds. Follow this by
‘shorting’ across the terminals with an insulated metal tool. A capacitor discharged in this
manner will be safe to touch.
Carefully remove both of the quick disconnect female terminals. Use a large needle nose-
pliers or similar clamping tool that you feel comfortably in control of and grasp the body of the
quick disconnect terminal to remove it. Do NOT pull directly on the copper wire or a broken
connection could occur.
