Servicing the at30, Troubleshooting chart – Exide Technologies Section 94.40 User Manual
Page 53

SERVICING THE AT30
49
3.4. TROUBLESHOOTING CHART
SYMPTOM PROBABLE
CAUSE
RECOMMENDED ACTION
Front panel 
meter 
displays all 
segments 
“On” or all 
segments 
“Off.” Charger 
may have no 
output. 
1. An external 
surge has 
interrupted 
operation of the 
microprocessor 
or the display 
controller. 
1A. Soft Reset of control board by pressing S7 reset switch. 
S7 is located inside the charger, on the control board’s right 
edge (as viewed from the rear of the front panel). This will 
restart the control board without modifying any settings. 
1B. Hard Reset of control board by pressing and holding the 
“UP” button on the front panel, and simultaneously pressing 
S7 reset switch. This will restart the control board and restore 
all settings to factory default. Reset parameters per Section 
2.3 of this manual. 
1C. Remove all power from the AT30 to allow control board to 
discharge all voltages. This can be done by opening the AC 
circuit breaker and disconnecting the control board plug(s). 
Keep power removed for approximately 5 minutes to allow 
voltages to discharge. 
AC breaker 
trips (or fuses 
clear) 
immediately 
1. Shorted 
rectifier diode 
or SCR 
 
 
 
 
2. Defective 
wiring to T1 or 
to rectifier 
bridge 
3. Defective 
transformer T1 
1. Test by disconnecting wires #
7, 8 & 9 at the rectifier
module(s) (A16) mounted on the main heat sink(s), or at the 
main transformer (T1). Measure resistance between the ac 
terminals (bottom terminals) on the rectifier module(s). It 
should be at least 100,000 Ohms (check both polarities). If 
resistance is low in either direction, replace the rectifier 
module(s) (A16) as needed. 
2. Check spacing of terminals and check wiring for signs of 
insulation damage, burns, etc. Repair as necessary. 
 
 
3. Test by disconnecting wires # 
7, 8 & 9 from the transformer
secondary taps (T1-X1, X2 and X3). If ac breaker still trips, 
test by disconnecting wires # 
42, 43, 44, 45, 35 and 36 from
the tertiary taps (T1-Y0, Y1, Y2, Y3, W1 and W2). If ac breaker 
still trips, replace the transformer (T1). 
AC breaker 
trips (or fuses 
clear) after a 
few minutes 
1. Loose 
connection to 
breaker/fuse 
2. Wrong ac 
voltage, or T1 
taps miswired 
3. Open SCR 
 
 
 
4. SCR not 
controllable 
1. Check and tighten connections as required. 
 
 
2. Be sure the transformer primary taps (T1-H1, H2 and H3) 
are wired correctly for your input voltage. See Section 1.6 for 
details. 
3. Use a clamp-on ammeter to measure the current in wires # 
7, 8 & 9, between T1 and the rectifier modules. If it less than 
50% of the dc output current, one of the six (6) SCRs or 
diodes is defective. Replace the rectifier module(s) (A16). 
4. Disconnect the wire harness plug from connector J26 on the 
top of the Gate Driver pc board (A15) and restart the AT30. If 
you are able to measure output current, one of the SCRs is 
defective. Test and replace the rectifier module(s) (A16) as 
needed. 
