Removal and Replacement of Knobs

WARNING

e . Timers. The charge timers control

Dangerous voltages are present within the

t h e length of the charge cycle, while

equipment. Always disconnect power cable

t h e discharge timer determines whether

before opening up the unit for inspection or

t h e battery has passed or failed the

service.

c a p a c i t y t e s t . C h e c k the timers for

c. Power Cable Assembly. The power cable assembly

p r o p e r switchover points, with the equip-

is a three-wire cable terminated by a 4-pin connector,

m e n t turned off, by turning the timer

P3. A defective cable maybe indicated when operation

k n o b s ccw until. a click is heard, The

of front-panel switching does not energize the equip-

c l i c k for the charge timers should occur

ment. Check cable continuity; if an open or high-resist-

a t the 1 h o u r point. The click for the

ance is indicated, the cable is defective and should be

d i s c h a r g e timer should occur at the 6 0

replaced.

m i n u t e s setting. If the switchover

d. Fuse. Fuse F2 is rated for 100 amperes and pro-

points (clicks) occur at other than those

tects the charger circuits against external battery ca-

t i m e s given above, then an adjustment is

ble shorts or reverse connections. If the equipment is

r e q u i r e d . If necessary, the switchover

energized when ac power is supplied but the battery

p o i n t cm be corrected by loosening and

does not charge, or no voltage is measured on voltmet-

r e a d j u s t i n g the timer knobs.

er (M4) with switch (S3) in the W-volt position, F2

should be suspected. Fuse F2 is located inside the unit

4-9. Removal and Replacement of Knobs

at the top right side and is retained by blade-type con-

tacts. Remove the fuse, check continuity and replace,

Each of the control knobe is secured to the respective

shaft by two setscrews before removing a knob, set the

if necessary.

control to a readily identifiable position so that there-

placement knob can be set accurately to the same origi-

nal position. To replace a knob, loosen or remove the

setscrew and carefully lift the knob from the shaft. Be-

fore replacement, check to see that the knob dial point-

er tracks properly with dial markings.

Change 1

4-3