IB02602004E
For more information visit: www.eaton.com
Instructional Literature
Effective: May 2008
Page
173
Instructions for the FP-6000 Protective Relay
Figure 70. Thermal Replica Model Limit and Trip Curves with RTD.
Note that the FP-6000 calculates the positive and negative
sequence currents based on the three phase fundamental current
phasors, which are different from those of the MP-3000 that are
sample-based RMS values. Without current harmonics, the
FP-6000 thermal model behaves the same as the MP-3000. With
current harmonics, the FP-6000 thermal model tends to be less
sensitive. Therefore, depending on the nature of currents
measured, the thermal threshold may need to be set a bit
conservatively if the currents may have a considerable amount
of harmonics.
Note:
For direct temperature tripping, alarming, and displays, an URTD
module must be connected and be communicating with the relay. How-
ever, the settings for temperature can be viewed or adjusted with or with-
out a URTD module connected.
Ther
ma
l Repli
ca
Li
m
it
a
nd Trip Cur
v
es With RTD=100C
10
100
1000
1
0.1
1
10
100
Multiple of Full Lo
a
d A
m
pere
Ti
m
e in se
c
onds
SF=1,TC=100%
Ith=150%,Tth=80%*TC
1
0.1
1
10
100
