Basler Electric BE1-50/51B-231 - Manual (Page 32)

4-2 BE1-50/51B-231 Installation 9252000895 Rev C
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
Equation for time to trip during rewind (before relay is reset).
( )( )
Rewind Full
Time Rewind Trip Full
T
Occurence This Trip
=
Second Operation
( )( )
15.5
3 0.209
T
B
=
seconds 0.040 T
B
=
Third Operation
( )( )
15.5
11.96 0.209
T
C
=
seconds 0.161 T
C
=