RFL 9780 RFL Electronics Inc.
April 8, 2003 6-13 (973) 334-3100
6.4.9 CONFIGURATION OF GUARD BEFORE TRIP/TRIP AFTER GUARD
TIMERS
Trip After Guard (TAG): The position of switches SW5-1 through SW5-4 determines the time the Trip
channel will remain open after a loss of valid Guard.
Guard Before Trip (GBT): The position of switches SW5-5 through SW5-8 determine the amount of
valid Guard time required before the Trip channel is opened /re-opened (GBT).
The time period shown in Table 6-12 for each switch position is cumulative. A switch in the ON
position enables its corresponding time period. An offset of 40ms is added to this in order to calculate
the total time period. The selectable timer range is between 50ms and 190ms in increments of 10ms.
NOTE: When all switches (SW5-1 through SW5-8) are in the OFF position, the GBT/TAG
function is disabled. Additionally, setting only GBT or TAG to all OFF is not valid.
Table 6-12. Configuration of Guard Before Trip / Trip After Guard Timers
TAG Switches SW5-1 SW5-2 SW5-3 SW5-4
GBT Switches SW5-5 SW5-6 SW5-7 SW5-8
Time (ms) 80 40 20 10
Example: The Guard Before Trip configured for a time period of 150ms would be set as follows:
SW5-5: ON 80ms
SW5-6: OFF 0ms
SW5-7: ON 20ms
SW5-8: ON 10ms
OFFSET 40ms
TOTAL 150ms
NOTE
Because many of the timer functions interact, careful selection of these is necessary. When
GBT/TAG is enabled, the alarm pickup timer must be set to a value greater than the TAG
setting. It is also recommended that the alarm dropout timer be set to a value less than the GBT
setting.
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