- 233 -
(v) Signal of OC trip
When a user requires an alarm signal in place of the trip signal; for example, set Alarm
for the scheme switch [OC1-UseFor]. Trip is set for the scheme switch [OC1-UseFor] for
the normal trip operation.
2.15.6 Scheme logic
The scheme logic for both the non-directional and the directional OC1 element is illustrated in
Figure 2.15-8; Figure 2.15-9 shows grouping commands for the trip circuit (TRC). Each phase
of the OC1 element issues a pick-up when a current has been exceeded over the setting; then
the pick-up signal is transferred to into the TRC as trip signals. (For more information, see
Chapter
Relay application: Trip circuit function
)
Figure 2.15-8 Scheme logic for the OC1
†Note: The presence of ‘OC1-OR’ and ‘OC1PU-OR’ signals depends on the operation
characteristic defined with setting [OC1_Timer], as shown in Table 2.15-7.
Table 2.15-7 Signal behaviors of PLC monitoring points ‘OC1-OR’ and ‘OC1PU-OR’
IEC-NT,VI,EI, UK-LTI, IEET-MI,VI,EI, US-CO2,CO8, ORIGINAL
○
1
: A pick-up signal is generated instantly when the element operates.
To Next Page
Loading...
