Switch Mode Power Supply
S8VM
13
Probable cause of error
Troubleshooting methods
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1
A momentary power failure has occurred in the
input.
Check that the output voltage is normal and no problems have occurred in other devices. No problems
will be caused by continuing to use the Power Supply as is. To clear DC LOW1 (LED display and tran-
sistor output status), turn OFF the input power, and wait at least 60 s before turning ON the input Power
Supply again.
2
A momentary overload has occurred.
The load current has probably exceeded the rated current. We suggest reducing the connected load
or replace the Power Supply with one that has a higher capacity.
A momentary output voltage drop has occurred
at startup due to the capacity of the capacitive
factors on the load side or when the load is acti-
vated.
A large inrush current has probably flowed to the load side at startup. We suggest replacing the Power
Supply with one that has a higher capacity.
The output voltage has returned to normal volt-
age following a rapid drop caused by using the
output voltage adjuster (V.ADJ).
Turn OFF the input power, and wait at least 60 s before turning ON the input power again to clear the
indicator status.
Deterioration due to age (when the Power Sup-
ply has been used for several years)
The internal parts of the Power Supply may have deteriorated due to age. We suggest replacing the
Power Supply. Also replace other Power Supplies that were purchased at the same time.
3
Overload (immediately following first use of the
Power Supply or when increasing the load)
The load current has probably exceeded the rated current. Check the actual load current and Power
Supply capacity. Continued use in overload status may damage the Power Supply.
The output voltage dropped to -10% or lower of
the rated voltage resulting from using the output
voltage adjuster (V.ADJ)
Adjust the output voltage to the rated values using the output voltage adjuster (V.ADJ).
A sudden overload occurred and the Power
Supply remains in overload status.
An error has probably occurred in the load device. Turn OFF the input power, and check whether any
errors have occurred in the load device. Continued use in overload status may damage the Power Sup-
ply.
4
The output voltage remains low after a rapid
voltage drop caused by using the output voltage
adjuster (V.ADJ).
Adjust the output voltage to the rated values using the output voltage adjuster (V.ADJ). To clear DC
LOW1 (LED display and transistor output status), turn OFF the input power, and wait at least 60 s be-
fore turning ON the input power again.
The overload status continues to fluctuate fol-
lowing a sudden overload.
An error has probably occurred in the load device. Turn OFF the input power, and check whether any
errors have occurred in the load device. Continued use in overload status may damage the Power Sup-
ply.
5
Deterioration due to age (after using the Power
Supply for several years)
The internal parts of the Power Supply may have deteriorated due to age. Replace the Power Supply.
Also replace other Power Supplies that were purchased at the same time.
6
Overload (immediately following first use of the
Power Supply or when increasing the load)
The load current has probably exceeded the rated current. Check the actual load current and Power
Supply capacity. Continued use in overload status may damage the Power Supply.
Power Supply interrupted or damaged.
Check whether the input power is being applied correctly. If there is no output even though the input
power is applied correctly, the internal circuit is probably damaged.
7
Overvoltage protection operation
Turn OFF the input power, and wait at least 3 min before turning ON the input power again. If the same
status recurs, the internal circuit is probably damaged.
The short bar has fallen off, or the +S and -S ter-
minals are open.
Check whether the +S and -S terminals are open. If so, the overvoltage protection function is activated.
Therefore, turn OFF the input power and wait at least three minutes before turning it ON again. (S8VM-
10024A
@
/P
@
and S8VM-15024A
@
/P
@
models only)
Output short-circuit
Remove the cause of the output short-circuit.
Intermittent operation due to overload (S8VM-
01524A
@
/03024A
@
only)
The load current has probably exceeded the rated current. Check the actual load current and Power
Supply capacity. Continued use in overload status may damage the Power Supply.
8
The Power Supply fails to start repeatedly due
to the capacity of the capacitive factors on the
load side.
A large inrush current has probably flowed to the load side at startup. We suggest replacing the Power
Supply with one that has a higher capacity.
The input turns ON and OFF repeatedly.
Check whether the Power Supply’s input voltage is being applied correctly.
The status repeatedly switches between normal
operation and output short-circuit.
An error has probably occurred in the load device. Turn OFF the input power, and check whether any
errors have occurred in the load device.
