Omron S8AS, User Manual

Page: 15 / 146

xv
■
Abnormal Current Tripping
The S8AS has an abnormal current tripping function. A branch output will be cut off if its current exceeds a pre-
set value. Also, all branch outputs will be cut off if their total peak output current exceeds a specified value.
Note
1. Continuing operation with overcurrent may occasionally result in deterioration or destruction of internal ele-
ments.
2. Do not use the S8AS for applications in which load inrush current or overload will frequently occur.
Doing so may result in deterioration or damage to internal components.
■
Maintenance Forecast Monitor Function
The accuracy of the maintenance forecast monitor function will be reduced in applications where the AC input
turns ON and OFF frequently.
■
Tripping Performance
There are three methods that can be used to determine abnormal current trippings: Standard Detection,
Instantaneous Detection, and Extended Detection. (This is not possible for the S8AS-24006N/48008N.)
Refer to
2-4-2 Over-current Protection Functions for details of cutoff performance.
Note
1. When the tripping alarm output operates, always remove the cause of the output first and then reset the
alarm.
2. When using a load with a fixed-power operation, the S8AS may cause a cutoff when the power supply is
turned OFF.
3. Tolerance of current tripping alarm threshold is
±
0.3 A.
4. Use Extended Detection only when using OMRON Remote I/O Terminal with short-circuit detection.
■
Total Peak Output Current
The S8AS is designed to provide a temporary peak current to provide the overcurrent required to start load
devices.
The total peak output current for all branch outputs combined is given below.
If the total current exceeds any of these values, all branch outputs will be cut off according to the size of the
peak current or application time to ensure safety.
•
240-W Models
Input voltage range: 200 to 240 VAC
Peak current/Peak current pulse width: 17 A max. for 2 s max.
15 A max. for 5 s max.
13 A max. for 10 s max.
12 A max. for 20 s max.
If the total output peak current exceeds even one of these conditions, all branch outputs will be shut off to
ensure safety.
•
480-W Models
Input voltage range: 200 to 240 VAC
Peak current/Peak current pulse width: 27 A max. for 1 s max.
25 A max. for 2 s max.
22.5 A max. for 5 s max.
Note
1. If the input voltage range is not within the values specified above or the total output current exceeds the max-
imum peak current value, internal operation will become unstable and the branch outputs may be cut off.
2. Maintain the total current for normal operation after the load devices have started to within the rated ranges.