GE Power Management
735/737 Feeder Protection Relay 3-3
3 SETUP AND OPERATION 3.2 CONTROLS
3
3.2.3 PHASE TIME MULTIPLIER [3]
The time multiplier dial allows selection of a multiple of the base curve shape for every curve. It is adjustable from 1 to 10 in
increments of 1. Unlike the electromechanical time dial equivalent, trip times are directly proportional to the time multiplier
setting value. For example, all trip times on multiplier curve 10 are 10 times curve 1. Use the phase time multiplier shift
option switches to move the selected curve up or down (see Section 3.4.2: OPTION SWITCHES [14]). Curves are shown in
Chapter 5 for overlays and visual inspection. Formulas and tabular data are also given for use with computer software or
manual plotting on other co-ordination curves.
Figure 3–4: PHASE MULTIPLIER TIME SETTING
3.2.4 PHASE INSTANTANEOUS [4]
Instantaneous phase trip level with no intentional delay (35 ms max) is set with the phase instantaneous dial as a multiple
of the CT sensor. This setting is independent of the pickup dial setting.
For example: CT RATING: 500:5
INSTANTANEOUS TRIP: 5000 A
INSTANTANEOUS SETTING: 10 (i.e. 10 x 500 = 5000 A)
Figure 3–5: PHASE INSTANTANEOUS TRIP SETTING
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