TROUBLESHOOTING GUIDE
SYMPTOM
On switching on, LED (2) does not light.
Buzzer is off. There is no AC voltage
Buzzer alarm is sounded when load is
switched on. Voltage at DC input
terminals reads between 10 and 10.5 V
for PST-15S-12A or between 20 & 21
V for PST-15S-24A.
LED (2) is green.
AC output voltage is available.
Buzzer alarm is sounded when load is
switched on. Voltage at the DC input
terminals reads below 10 V for PST-
15S-12A or 20 V for PST-15S-24A.
LED (2) turns orange.
There is no AC output.
There is no AC output.
LED (2) turns orange.
Buzzer is on.
POSSIBLE CAUSE
There is no voltage at the DC input
terminals
Polarity of the input voltage has been
reversed that has blown the internal DC
side fuse
DC input voltage is less than 10.5 V for
PST-15S-12A or less than 21 V for PST-
15S-24A.
Shut-down due to low input DC voltage
(Less than 10 V for PST-15S-12A or 20 V
for PST-15S-24A).
Shut-down due to high input DC voltage
(> 16.5 V for PST-15S-12A or 33 V for
PST-15S-24A. ).
REMEDY
1. Check the continuity of the battery
input circuit.
2. Check that the battery fuse is intact.
Replace if blown
3. Check that all connections in the
battery input circuit are tight
Correct the polarity of the input
connections and replace the internal
fuse (
Note: Reverse polarity may
cause permanent damage)
If the unit does not work after replacing
the fuse, the unit has been permanently
damaged. Call Technical Support.
1. Check that the battery is fully
charged. Recharge, if low
2. Check that the battery cables are
thick enough to carry the required
current over the required length. Use
thicker cables, if required.
3. Tighten connections of the battery
input circuit
1. Check that the battery is fully
charged. Recharge, if low
2. Check that the battery cables are
thick enough to carry the required
current over the required length. Use
thicker cables, if required.
3. Tighten connections of the battery
input circuit
1. Check that the voltage at the DC
input terminals is less than 16.5 V for
PST-15S-12A or 33 V for PST-15S-
24A. .
2. Ensure that the maximum charging
voltage of the battery charger /
alternator / solar charge controller is
below 16.5 V for PST-15S-12A or 33
V for PST-15S-24A.
3. Ensure that an un-regulated solar
panel is not used to charge a battery.
Under cold ambient temperatures, the
output of the solar panel may exceed
18 V for a 12 V battery system or
36V for a 24V battery system. Ensure
that a charge controller is used
between the solar panel and the
battery
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