Omron S8AS User Manual page 23

Overview of Features and Functions
Maintenance Forecast
Monitor Function
Safety Functions
External Outputs
• The external output terminal for over-temperature (TMP) will turn ON.
(The photoswitch output will turn OFF.)
This function calculates the condition of the electrolytic capacitor based on the
power-ON time and internal temperature of the Power Supply to forecast
when the Power Supply needs to be replaced. The monitor value can be set to
between 0.0 and 5.0 years (approximate) in increments of 0.5 years.
The following occurs when the estimated replacement time reaches the set
value:
• The seven-segment display will show the error code A23 and the replace-
ment time (years) alternately.
• The external output terminal for the maintenance forecast monitor (LFE)
will turn ON. (The photoswitch output will turn OFF.)
If an abnormal voltage or current is detected, the semiconductor relay will cut
off the branch output. In the unlikely event that the semiconductor relay can-
not cut off an abnormal current or short-circuit current, the short-circuit protec-
tion fuse will cut the circuit to protect the system. If the branch output is cut off
by the fuse, an error indication will not be shown on the seven-segment dis-
play and the alarm output (TRP) will not operate.
The overcurrent protection fuse or over-temperature fuse cannot be replaced.
If a fuse burns out, use a different branch output or replace the S8AS.
The S8AS has 4 external outputs: the Tripping Alarm Output (TRP), Under-
voltage Detection Output (LOW), Maintenance Forecast Monitor Output
(LFE), and Over-temperature Output (TMP).
Output
Tripping Alarm • Abnormal voltage tripping
Output (TRP) If the output voltage exceeds
28.8 V, all branch outputs are
cut off.
• Abnormal current tripping
If a current exceeding the set
value is detected, the corre-
sponding branch output is
cut off.
Test Mode only
When even one branch output
is disconnected.
Undervoltage Detec- Output when the 24 VDC out-
tion Output (LOW) put falls below the undervolt-
age detection threshold.
Over-temperature Output when a temperature
Output (TMP) exceeding the threshold is
detected.
Maintenance Fore- • Output when the estimated
cast Monitor Output replacement time falls below
(LFE) the set value.
• Output when the replace-
ment time can no longer be
calculated due to rise in tem-
perature of the power supply
section.
Output condition
The output status is retained
when power is interrupted but
can reset with the reset oper-
ation.
Restore by connecting all
branch outputs, or by switch-
ing to any mode other than
Test Mode.
This output can be reset with
the reset operation. If the
alarm is cleared when the
power is turned ON, the out-
put will be reset.
The output is reset automati-
cally when the temperature
falls to 3°C below the over-
temperature output threshold.
• Prepare to replace the
• Take measures to lower the
Section 1-1
Restoration condition
Power Supply.
internal temperature.
5