IEC09000633-1-en.vsd
RFFwPE
X1+XN
R (Ohm/loop)
X (ohm/loop)
RFRvPE
RFRvPE
RFFwPE
R1PE+RN
RFRvPE
R1PE+RN
X1+XN
RFFwPE
IEC09000633 V1 EN-US
Figure 134: Characteristic of FRPSPDIS (21) for phase to fault (directional lines are drawn as
"line-dot-dot-line")
Besides this, the 3I
0
residual current must fulfil the conditions according to equation 77 and
equation
78.
EQUATION2108 V1 EN-US
(Equation 77)
0
0
3 _
3 max
100
I Enable PG
I Iph× ³ ×
EQUATION1812-ANSI V1 EN-US (Equation 78)
where:
IMinOpPE
is the minimum operation current for forward zones
3I
0
Enable_PG is the setting for the minimum residual current needed to enable operation in the phase-to-ground
fault loops (in %).
Iphmax is the maximum phase current in any of three phases.
Section 7 1MRK 502 066-UUS B
Impedance protection
278
Technical manual
To Next Page
Loading...
