Omron S8VS, Manual

Page: 20 / 38

S8VS
20
Overvoltage Protection
Consider the possibility of an overvoltage and design the system so
that the load will not be subjected to an excessive voltage even if the
feedback circuit in the Power Supply fails. If an excessive voltage that
is approximately 130% of the rated voltage (but approximately 110%
of the rated voltage for the S8VS-09024 @@@ S) or more is output, the
output voltage is shut OFF. Reset the input power by turning it OFF
for at least three minutes and then turning it back ON again.
Note: Do not turn ON the power again until the cause of the
overvoltage has been removed.
Inrush Current, Startup Time, Output Hold Time
Undervoltage Alarm Indication
LED (DC LOW: red) lights to warn of output voltage drop.
Detection voltage is set to approx. 80% (75 to 90%) of the rated output
voltage.
Note: This function monitors the voltage at the power supply output
terminals. To check actual voltage, measure voltage on the
load side.
Undervoltage Alarm Function (Indication and
Output) (S8VS-
@@@
24A
@@
/S8VS-
@@@
24B
@@
/
S8VS- @@@ 24BE @ Only)
When output voltage drop is detected, an alarm (
a01
) and lowest
output voltage value are indicated alternately. (
a01
can not be
displayed when the output voltage drops below 18.0 V.) The preset
value of detection voltage can be changed in the setting mode.
(From 18.5 to 27.5 V in 0.1-V steps. The value is fixed at 20.0 V for
the S8VS-06024A / S8VS-06024B.)
Further, an output (undervoltage output terminal (DC LOW)) to an
external device is given from the transistor to notify of the error
(excluding S8VS-06024A/S8VS-06024B/S8VS- @@@ 24BE @ ).
(Output voltage drop = OFF, i.e., no continuity at the undervoltage
output terminal (DC LOW).)
Example: Outputting an Alarm When the Voltage Output by the
S8VS-09024A @@ Drops to the Set Value (19.0 V) or Lower
:
Note: 1. Operation begins after about three seconds since the AC
power is supplied.
2. The alarm is not indicated in the setting mode.
3. Press the (Mode Key (8)) after the output voltage is
restored, to reset alarm indication.
4. The undervoltage alarm function may also operate when an
interruption in AC input is not restored within 20 ms.
5. The undervoltage alarm function monitors the output
terminal voltage of the Power Supply. To check the voltage
accurately, measure the voltage at the load end.
Note: Operation begins after about three seconds since the AC
power is supplied.
+15%
−
10%
0 V
+30%
(approx.)
Overvoltage protection
operating
Variable range
Rated output
voltage
Output v
oltage (V)
The values shown in the above diagram is for reference only.
90%
96.5%
Startup time (1,000 ms max.)
AC input
voltage
AC input
current
Output
voltage
Inrush current on input application
Input OFF
Input ON
Hold time
(20 ms min.)
In the case that the
output voltage drops
below the set value (19.0 V)
and an alarm is issued
AC input
Output
voltage
Undervoltage
output
Main display Voltage indication
Detection value
of Undervoltage
alarm
Operation
mode
Lowest value of
output voltage