Hitachi Relion 670 Series Applications Manual page 132

Section 7
Impedance protection
Therefore, set this to 0.83.
RFPEFwZ1: It should be set to give maximum coverage considering the arc resistance and tower
footing resistance.
Arc resistance = 2 Ohm primary and Tower footing resistance = 10 Ohm Primary. Therefore,
RFPEFwZ1 should be minimum of 12 Ohm.
Since the RFPEStart is set to 50.16 Ohm to give more resistive coverage, RFPEFwZ1 can be set at
0.8 x 50.16 = 40.13 Ohm. However, to avoid overreach due to the remote end infeed, it is
recommended that the resistive reach does not exceed 4.5 times reactive reach.
Therefore, RFPEFwZ1 may be set to 4.5 x X1FwZ1 = 4.5 x 5.6 = 25.52 Ohm.
RFPERvZ1: It may be set identical to RFPEFwZ1, which is 25.52 Ohm.
RFPPFwZ1: It should be set to cover the arc resistance for phase-to-phase faults. It may be set
identical to RFPEFwZ1, which is 25.52 Ohm.
RFPPRvZ1: It may be set identical to RFPPFwZ1, which is 25.52 Ohm.
TimerSelZ1: To set the zone timer selection mode of zone 1. Set this to Timers Separated.
OpModetPEZ1: Set this to On.
tPEZ1: Set this to 0.0s.
OpModetPPZ1: Set this to On.
tPPZ1: Set this to 0.0s.
Zone 2
OpZ2: Set this to On.
DirModeZ2: To set the zone 2 direction mode. Set this to Forward.
PhSelModeZ2: To enable the measuring loops of zone 2. Set this to Phsel logic.
LEModeZ2: To operate the load discrimination characteristic of zone 2. Set this to On.
LCModeZ2: To enable/disable the adaptive load compensation mode of zone 2. Set this to Off.
X1FwZ2: To set the forward positive sequence reactance reach of zone 2 in Ohm/p. This should be
set to 120% of line 1 reactance.
Therefore, set the X1FwZ2 to 1.2 x 50 x 0.112 = 6.72 Ohm.
X1RvZ2: Set this identical to X1FwZ2 which is 6.72 Ohm.
REoverRLZ2: It provides zero sequence compensation for phase-to-earth faults.
R 1

E
R 2
L
IECEQUATION15052 V1 EN-US
Therefore, set this to 0.28.
XEoverXLZ2: It provides zero sequence compensation for phase-to-earth faults.
126
 
 
R 1 . 0 151
   
   
 
0
1 1
 
 
R 2 . 0 097
1
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. 0 28
1MRK506375-UEN Rev. N
GUID-5D2EB529-C387-4548-845F-D92D60384327 v2
(Equation 30)
Railway application RER670
Application manual