Omron S8M - 2-2 Internal Configuration

16
Internal Configuration Section 2-2
2-2 Internal Configuration
S8M-CP04-R
• The S8M continuously converts the measured input voltage, current,
internal temperature, and run time from analog to digital and compares
these measured values to the preset parameters. These values can be
read on the S8M's seven-segment display or monitored remotely from the
Support Tool connected via the RS-232C port.
• When an error is detected, the branch output will be cut off or an alarm
will be output. The error code and PV will be displayed alternately on the
seven-segment display. The information can also be read from the Sup-
port Tool.
• When an abnormal voltage or current is detected, the semiconductor
relay will cut off the branch output. In the unlikely event that the semicon-
ductor relay cannot cut off an abnormal current or short-circuit current, the
short-circuit protection fuse (8.0 A minimum) will blow to protect the sys-
tem.
• The S8M has a built-in temperature sensor, which can detect a tempera-
ture rise inside the S8M. When the internal temperature exceeds the
alarm value, the Over-temperature Output (TMP) will be turned OFF. The
TMP output is independent of the alarm output, so it can be used to con-
trol cooling equipment to reduce the temperature in the control panel.
• The equipment's run time can be monitored in 0.1-kh (100-hour) units by
measuring the S8M's run time.
• When an internal circuit has failed, the components can generate exces-
sive heat. As a safety precaution against this kind of failure, the S8M is
equipped with a function that cuts off operation using a thermal fuse.
SD
RD
SG
DC input
power supply
+V
RS-232C
communica-
tions terminals
+
−
+
−
+
−
Tripping alarm output
(TRP)
Alarm output
(ALM)
Over-temperature output
(TMP)
External tripping input
(TRG)
+
−
−V
Power supply
circuit
Communica-
tions circuit
Voltage
detection
Display
circuit
Switches
Temperature
detection
Processing
circuit
Thermal fuse
Thermal fuse
Thermal fuse
Current-detec-
tion resistor
Cutoff
circuit
Current-lim-
iting circuit
Fuse
DC branch output 1
Current-detec-
tion resistor
Cutoff
circuit
Current-lim-
iting circuit
Fuse
Current-detec-
tion resistor
Cutoff
circuit
Current-lim-
iting circuit
Fuse
Current-detec-
tion resistor
Cutoff
circuit
Current-lim-
iting circuit
Fuse
−V
+V
+V
−V
+V
−V
+V
−V
DC branch output 2
DC branch output 3
DC branch output 4
Thermal fuse