SERVICING THE AT30
51
SYMPTOM
PROBABLE
CAUSE
RECOMMENDED ACTION
No output
current, and
AC ON
lamp
is out, but ac
and dc
breakers are
on
1. AC supply
failure
2. Input fuse
F1A/B/C blown
3. Defective
wiring
4. Defective
transformer T1
1. If the
AC ON
indicator is out, check the feeder circuit breaker or
fuse.
2. Remove the ac fuses (F1A, F1B and F1C) from the fuse
holder(s) and check if blown with an Ohmmeter or fuse tester.
Replace F1A, F1B, and/or F1C as needed.
NOTE: If the replacement fuses immediately blow, see the
Sections titled "AC breaker trips immediately" and "AC breaker
trips after a few minutes" for further troubleshooting hints.
3. Check terminals and wiring between T1 and the rectifier bridge
assembly, main inductor (L1), dc filtering assembly (if present), dc
breaker (CB2), optional dc fuses (F3/F4), and the output terminals
(TB1+/-). Check wires #
42
through #
45
from T1-Y0 through T1-
Y3 to the Gate Driver board connector (J25). Repair as
necessary.
4. Use an ac voltmeter to measure the ac voltage from T1-X1 to
T1-X2 and T1-X3. It is normally 50% to 80% higher than the rated
dc output voltage. If it is too low, check the wiring of the
transformer primary taps (T1-H1 through T1-H3). See Section 1.6
for details. If the ac primary voltage is
zero
, replace the T1.
No output
current, but
AC ON
lamp
is on, and ac
and dc
breakers are
on
1. Battery is fully
charged
2. Float or
Equalize voltage
set too low
3. Wrong ac
input voltage, or
mistapped T1
4. Defective
wiring
5. Defective
rectifier bridge
6. Defective
Gate Driver
circuit board
7. Defective
transformer T1
8. Defective
inductor L1 or L2
9. Defective dc
breaker (CB2)
1. This is normal operation in a system with little or no dc load. As
long as the AT30 maintains Float voltage, it is operating normally.
2. Check the Float and Equalize voltages and adjust them if
necessary. Consult your battery manufacturer for the proper
voltage settings.
3. Be sure the transformer primary taps (T1-H1, H2 and H3) are
wired correctly for your input voltage. See Section 1.6 for details.
4. Check terminals and wiring between T1 and the rectifier bridge
assembly, main inductor (L1), dc filtering assembly (if present), dc
breaker (CB2), optional dc fuses (F3/F4), and the output terminals
(TB1+/-). Repair as needed.
5. Use an ac voltmeter to measure the voltage between the SCR
gate leads on each SCR module. If you measure about 1.0V rms,
but there is no output current, replace the rectifier module(s)
(A16) as needed.
6. If you do not measure any ac voltage in step 5 above, and the
battery voltage is less than the Float voltage setting, replace the
Gate Driver circuit board (A15).
7. Use an ac voltmeter to measure the ac voltage between the
transformer secondary taps (T1-X1, T1-X2 & T1-X3). The line-to-
line voltage is normally the same as the rated dc output voltage. If
it is too low, check the wiring of the transformer primary taps (T1-
H1, T1-H2 & T1-H3). See Section 1.6 for details. If the ac voltage
on the transformer secondary taps is
zero
, replace T1.
8. Disconnect the wiring from inductor (L1) and measure the
resistance between the terminals. If it is an open circuit, replace
L1. Repeat for inductor (L2) if the optional dc filter is installed.
9. Disconnect the battery, and connect a light dc load to the AT30.
Measure the dc voltage across TB1(+) and TB1(-), with the dc
circuit breaker (CB2) on. If no voltage is measured, replace CB2.
Summary of Contents for AT30 SERIES
Page 99: ......
