Schweitzer Engineering SEL-351P, Quick Start Manual

Page: 124 / 674

1-28 Factory-Set Logic Date Code 990215
SEL-351P Manual Técnico
DWG: MP351P016
Relay
Word
Bits
51P1
51P2
51G1
51G2
51N1
51N2
At least one fast curve or
delay curve is picked up
Ground current above cold
load ground min. trip
(see Figure 3.9)
Cold load pickup scheme
actively engaged for SEF
element (see Figure 1.4)
Ground current above cold
load ground min. trip
(see Figure 3.11)
SEF element
operates on cold
load ground min.
trip
67N3TC
Input into
67N3T logic
(see Figure 3.8)
SEF HABILITADO operator
control ON (see Figure 1.41)
50N5
SV12
50G5
LT5
SEF element
operates on cold
load ground min.
trip
Figure SECTION 1: .18: SEF Element Enable/Disable Logic
T
RIP
L
OGIC
See Figure SECTION 1: .19. The overcurrent elements in Figure SECTION 1: .19 are
controlled by the logic in Figure SECTION 1: .15 through Figure SECTION 1: .18. Other trip
logic details:
•
If setting Min. trip - ground is set below 0.1 Amp secondary, 51N1T and 51N2T operate
as Fast curve - ground and Delay curve - ground, respectively (51G1T and 51G2T are
turned off automatically). Otherwise, 51G1T and 51G2T operate as Fast curve - ground
and Delay curve - ground, respectively (51N1T and 51N2T are turned off
automatically).
•
If setting High current trip - ground is set effectively below 0.05 Amp secondary,
67N2T operates as High current trip - ground (67G2T is turned off automatically).
Otherwise, 67G2T operates as High current trip - ground (67N2T is turned off
automatically).
Figure SECTION 1: .19 propagates into the trip logic (see Figure 5.1). The trip signal output
(Relay Word bit TRIP) is then routed to the final trip/close logic and subsequent output contacts
(see Figure 7.29).