Schweitzer Engineering Laboratories SEL-311C - Convert SEL-221 G-5 Settings to SEL-311 C Settings; Table 14.5 SEL-311 C Settings Calculated from SEL-221 G-5 Settings; Convert SEL-221 G-5 Primary Quantities to SEL-311 C Secondary Quantities

14.12
SEL-311C Relay Instruction Manual Date Code 20060320
Application Settings for SEL-221 Series Relays
SEL-221G-5 to SEL-311C Settings Conversion Guide
Convert SEL-221G-5
Primary Quantities to
SEL-311C Secondary
Quantities
All SEL-221G-5 current settings must be converted from primary to
secondary amps to be used in the SEL-311C. Divide the SEL-221G-5 current
setting by the current transformer ratio setting (CTR) to make the change.
SEL-221G-5 impedance settings must be converted from percent of primary
line impedance to secondary impedance in ohms. For example, the Zone 1
distance setting in the SEL-311C (Z1P) is calculated as
Equation 14.2
Convert SEL-221G-5
Settings to SEL-311C
Settings
Table 14.5 shows all the SEL-311C settings that must be entered for the relay
to perform protection similar to the SEL-221G-5 when APP = 221G5.
Calculate each SEL-311C setting from SEL-221G-5 settings using the
formula shown. Instruction manual references are to subsection headings
rather than to section headings.
where:
Z1% = the SEL-221G-5 distance reach setting
Z1MAG = the SEL-311C positive-sequence line impedance setting
in secondary ohms
Z1P = the SEL-311C Zone 1 reach setting in secondary ohms
Z1P
Z1%
100
------------
Z1MAG• =
Table 14.5 SEL-311C Settings Calculated From SEL-221G-5 Settings (Sheet 1 of 3)
SEL-311C
Setting
a
Calculated From SEL-221G-5 Settings
SEL-311C Instruction
Manual Section
SEL-221G-5 Instruction
Manual Section
RID None Settings Sheets for the
SEL-311C Relay
Section 3—Set n
TID = ID
CTR = CTR Settings Sheets for the
SEL-311C Relay
Section 5—Choosing Current and
Potential Transformers
CTRP = CTR
PTR = PTR
PTRS = PTR
Z1MAG
Settings Sheets for the
SEL-311C Relay
Section 5—Choice of
Line Impedances
Z1ANG
Section 5—Choice of Maximum
Torque Angle (MTA)
Z0MAG
Z0ANG
LL = LL Settings Sheets for the
SEL-311C Relay
APP None
EFLOC = LOCAT Settings Sheets for the
SEL-311C Relay
Section 2—Fault Locator
ELOP
N
Y
= LOPE
= N
= Y
Loss-of-Potential Logic on
page 4.1
Section 5—Loss-of-Potential Logic
R1
2
X1
2
+()=
CTR
PTR
------------
•
Arc tan
X1
R1
-------
= (degrees) = MTA
R0
2
X0
2
+()=
CTR
PTR
------------
•
Arc tan
X0
R0
-------
= (degrees)