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1MAC050144-MB C
Section 4
Protection functions
615 series ANSI
255
Technical Manual
Equation 9
t(s)
the trip time in seconds
d
the Constant delay setting in milliseconds
M
the excitation value (V/f ratio or volts/hertz) in pu
k
the Time multiplier setting
Figure 121:
Trip time curves for the overexcitation IDMT curve 4 ("OvExt IDMT
Crv4") for different values of the Time multiplier setting when the
Constant delay is 800 milliseconds.
The activation of the TRIP output activates the BLK_RESTART output.
For the IDMT curves, the deactivation of the TRIP output activates the cooling timer. The
timer is set to the value entered in the
Cooling time
setting. The COOL_ACTIVE output
is kept active until the cooling timer is reset, whereas the BLK_RESTART output remains
active until the timer exceeds the value to enable the restart time, given in
Equation 10
.
The
Restart Ena level
setting determines the level when BLK_RESTART should be
released.
Equation 10
If the excitation level increases above the set value when BLK_RESTART is active, the
TRIP output is activated immediately.
2
)
1
(
18
.
0
1000
)
(
M
k
d
s
t
time
Cooling
level
restart
Ena
time
restart
enable
100
100
Summary of Contents for 615 Series ANSI
Page 1: ...Relion Protection and Control 615 series ANSI Technical Manual ...
Page 2: ......
Page 29: ...1MAC050144 MB C Section 615 series ANSI 22 Technical Manual ...
Page 389: ...Section 4 1MAC050144 MB C Protection functions 382 615 series ANSI Technical Manual ...
Page 485: ...Section 6 1MAC050144 MB C Supervision functions 478 615 series ANSI Technical Manual ...
Page 635: ...Section 10 1MAC050144 MB C Other functions 628 615 series ANSI Technical Manual ...
Page 711: ...Section 16 1MAC050144 MB C Glossary 704 615 series ANSI Technical Manual ...
Page 712: ......