Basler BE1-50/51B-233, Инструкция по эксплуатации

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4-2 BE1-50/51B-233 Installation 9252000897 Rev A
reclosing relay is set for two reclose attempts at 3 and 15 seconds after the initial trip. If a permanent fault
occurs (magnitude ten times pickup), calculate the feeder breaker trip time for each of the three
operations. Refer to Section 1 for characteristic curve constants.
From the time characteristic curve equation.
K BD
C M
AD
T
N
Trip
+ +
−
=
( )
028 0 2 02758 . 0
1 10
2 7624 7
0938 2
.
.
.
+ × +
−
×
=
( )
028 0 05516 . 0
1 10806 124
5248 15
.
.
.
+ +
−
=
seconds 0.29
=
From the reset characteristic curve equation.
1 M
RD
T
2
Reset
−
=
seconds 15.5
1 0
2 7.75
2
− =
−
×
=
M = 0 if current goes to zero.
Negative result indicates reset time.
Results: Full trip = 0.209 seconds and full reset = 15.5 seconds if current goes to zero.
In Figure 4-1,
T
A
= 0.209 seconds (relay was at reset).
T
B
= value < T
A
because rewind has not gone to zero.
T
C
= value < T
A
because rewind has not gone to zero.
Figure 4-1. Coordination Timing Diagram