Functions
2.7 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66, Load Jam Protection)
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
147
Example:
Motor with the following data:
The setting for address
4402
Load Jam I>
as secondary value is calculated as follows:
The tripping delay time can remain at the default setting of 1 s. The warning threshold is set to 75% of the trip-
ping element (
4404
I Alarm
≡
0.95 A sec.).
The tripping delay time can remain at the default setting of 2 s.
In order to block the function during motor startup, the parameter
4406
T Start Blk.
is set to double startup
time (
T Start Blk.
= 2 · 8.5 s = 17 s).
Nominal voltage
V
Nom
= 6600 V
Nominal current
I
Nom
= 126 A
Long-term current rating
I
max
= 135 A
Startup duration
T
startmax.
= 8.5 s
Current transformer
I
NomCTprim
/
I
NomCTsec
= 200 A / 1 A
Summary of Contents for SIPROTEC 7SK80
Page 8: ...Preface SIPROTEC 7SK80 Manual E50417 G1140 C344 A5 Release date 11 2012 8 ...
Page 496: ...Literature SIPROTEC 7SK80 Manual E50417 G1140 C344 A5 Release date 11 2012 496 ...
Page 508: ...Glossary SIPROTEC 7SK80 Manual E50417 G1140 C344 A5 Release date 11 2012 508 ...
Page 512: ...Index SIPROTEC 7SK80 Manual E50417 G1140 C344 A5 Release date 11 2012 512 ...