Schweitzer Engineering Laboratories SEL-352-1 - Flashover Protection Scheme 2; Unbalanced Current Protection

Date Code 20010731 Setting the Relay 7-23
SEL-352-1, -2 Instruction Manual
Flashover Protection Scheme 2
The default SEL
OGIC control equation settings for the flashover protection logic Scheme 2
follow:
F1A =X59LA
F1B =X59LB
F1C =X59LC
F2A =50LDA
F2B =50LDB
F2C =50LDC
F3A =TRIPA + CLOSE + MCLOSE
F3B =TRIPB + CLOSE + MCLOSE
F3C =TRIPC + CLOSE + MCLOSE
LHAS =F1AD
LHAR =!50LDA
LHBS =F1BD
LHBR =!50LDB
LHCS =F1CD
LHCR =!50LDC
LVAS =LHAQ*!F2AD*50LDA*!52AA*!F3AD
LVAR =!50LDA + F3AD + 52AA
LVBS =LHBQ*!F2BD*50LDB*!52AB*!F3BD
LVBR =!50LDB + F3BD + 52AB
LVCS =LHCQ*!F2CD*50LDC*!52AC*!F3CD
LVCR =!50LDC + F3CD + 52AC
FPA =LVAQ
FPB =LVBQ
FPC =LVCQ
FFA =LVAQ
FFB =LVBQ
FFC =LVCQ
FOPF =FPAD + FPBD + FPCD
FOBF =FFAD + FFBD + FFCD
Unbalanced Current Protection
The default SEL
OGIC control equation settings for the unbalanced current protection logic
follow:
UC =CLOSE + MCLOSE
LUS =UCD*50LD*(46A + 46B + 46C) NOTE: !(X + Y) => !X * !Y
LUR =!50LD + !(46A + 46B + 46C) !(X * Y) => !X + !Y
UPA =LUQ*46A
UPB =LUQ*46B
UPC =LUQ*46C
UFA =LUQ*46A
UFB =LUQ*46B
UFC =LUQ*46C
UBPF =UPAD + UPBD + UPCD
UBBF =UFAD + UFBD + UFCD