Omron S8AS, User Manual

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11
Table of Basic Functions
Section 1-3
Tripping/
Alarm Functions
There are three ways for the S8AS's tripping function to operate:
• Tripping by user-set parameters
• Tripping by the S8AS's system monitor
• Tripping by external operation
The external signal outputs include the Tripping Alarm Output (TRP), Under-
voltage Detection Output (LOW), Maintenance Forecast Monitor Output
(LFE), and Over-temperature Output (TMP).
Tripping Functions
Note (1) The tripping function operates within 100 ms when the S8AS is set to
standard detection, within 20 ms when it is set to instantaneous detec-
tion, and within 1,000 ms when it is set to extended detection.
(2) The TRG signal applies only to the branch outputs for which the external
tripping input is enabled. For details, refer to 2-7 External Tripping Input
Function .
Protection level The Protection Level function can restrict parameter
read/write access by setting one of three levels. The
default protection level is level 1. 0 to 2
Reset operation The tripping alarm output and alarm output can be
cleared after removing the cause of the alarm by the
following two methods.
• KEY: RST Key only.
• ALL: RST Key or turning power OFF and ON again.
KEY, ALL
Data name Detail Setting
range
Setting Operating range Parameter
settings
Outputs
cut off
Abnormal volt-
age tripping Output cut off for voltage over 28.8 VDC. None All branch
outputs
Short-circuit
current
tripping Output cut off at 16 A for 20 ms max.
Output cut off at 11 A for 60 ms max. None Individual
branch out-
put
Abnormal total
current trip-
ping Output cut off when the sum of all branch
output currents exceeds the set value for
a specific length of time. None All branch
outputs
Abnormal
current
tripping
(See note 1.) 0.5 to 3.8 A (in 0.1-A increments)
Select from standard, instantaneous, and extended
detection methods.
Individual
branch out-
put
External trip-
ping input • External input signal (TRG) ON
• Tripping by communications. Specified
output
(See note
2.)