Hitachi RET670 User Manual

Table 31: Test points for phase-to-earth L3-E (Ohm/Loop)
Test point Reach Value Comments
1 X (2 x X1
set
+X0
set
)/3
R 0
2 X (2 x X1
set
+ X0
set
)/3
R (2 x R1
set
+ R0
set
)/3
3 X 0.8 x (2 x X1
set
+ X0
set
)/3
R 0.8 x (2 x R1
set
+ R0
set
)/3
+RFPEZx
4 X 0.5 x (2 x X1
set
+ X0
set
)/3
R 0.5 x (2 x R1
set
+R0
set
)/3 +
RFPEZx
5 X 0.85 x RFPEZx x tan(ArgLd) If RLdFw < 0.85 x RFPEZx
R 0.85 x RFPEZx
6 X RLdFw x tan(ArgLd) If RLdFw < RFPEZx
R RLdFw
7 X 0 If RLdFw < RFPEZx
R RLdFw
8 X -0.8 x R
min
x tan( ArgDir) R
min
= minimum of RFPEZx and RLdFw
ArgDir = 15⁰ fixed
R 0.8 x R
min
9 X -0.4 x R
min
x tan( ArgDir) R
min
= minimum of RFPEZx and RLdFw
ArgDir = 15⁰ fixed
R 0.4 x R
min
10 X 0.5 x (2 x X1
set
+ X0
set
)/3 ArgNegRes = 120⁰ fixed
Formula applies if R Set value < RFPEZx
R -0.5 x (2 x X1
set
+ X0
set
)/3 x
tan( ArgNegRes-90⁰)
11 X 0.8 x (2 x X1
set
+ X0
set
)/3 ArgNegRes = 120⁰ fixed
Formula applies if R Set value < RFPEZx
R -0.8 x (2 x X1
set
+ X0
set
)/3 x
tan( ArgNegRes-90⁰)
12 X 0.5 x (2 x X1
set
+ X0
set
)/3
R 0.5 x (2 x R1
set
+ R0
set
)/3
13 X 0 If RFPEZx < RLdFw
R RFPEZx
11.4.7.3 Measuring the operating limit of set values
GUID-3FA4B640-38E7-406E-8FCC-8DEDABB024C4 v5
Procedure:
1. Subject the IED to healthy normal load conditions for at least two seconds.
2. Apply the fault condition and slowly decrease the measured impedance to find the operating
value of the phase-to-phase fault for zone 1 according to test point 1 in figure and table .
Compare the result of the measurement with the set value.
3. Repeat steps
1 to 2 to find the operating value for test points 2, 3 in table
Observe that the zones that are not tested have to be blocked and the zone that is tested has
to be released.
4. Repeat steps
1 to 3 to find the operating value for the phase-to-earth fault L3-E according to
figure and table .
Section 11 1MRK 504 165-UEN Rev. K
Testing functionality by secondary injection
120 Transformer protection RET670
Commissioning manual
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Hitachi RET670 Specifications

General

Brand	Hitachi
Model	RET670
Category	Control Systems
Language	English