IECEQUATION17021 V1 EN-US
The factors k
1
and k
2
[Ω] are derived during the calibration measurements under
commissioning. As support for the calibration, the Injection Commissioning tool must
be used. This tool is an integrated part of the PCM600 tool.
In connection to this calibration, the reference impedance is also derived. In case of a
rotor ground fault with fault impedance Z
f
, the measured admittance is:
EQUATION2405 V2 EN-US
The real part gives the fault conductance.
EQUATION2421 V2 EN-US
RAlarm and RT
rip
are the two resistance levels given in the settings. The values of
RAlarm and RTrip are given in Ω.
An alarm signal ALARM is given after a set delay tAlarm if R
f
< RAlarm.
A initiate signal BFI is given if R
f
< RTrip.
For the tripping times, see figure
158.
Accuracy for ROTIPHIZ (64R) is installation dependent because harmonics in static
excitation system, large variation of the ambient temperature and variation of rotor
capacitance and conductance to ground between standstill and fully loaded machine
will limit the possible setting level for the alarm stage. As a consequence 50 kΩ
sensitivity can be typically reached without problem. Depending on particular
installation alarm sensitivity of up to 500 k
Ω may be reached.
1MRK 502 071-UUS A Section 8
Impedance protection
Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062 315
Application manual
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