Class Conversion - Siemens SIPROTEC 4 Manual

D.2

Class conversion

Table D-1
British Standard BS 3938
ANSI/IEEE C 57.13, Klasse C
IEC 60044-6 (transient response),
class TPS
Classes TPX, TPY, TPZ
SIPROTEC 4, 7SJ80, Manual
E50417-G1140-C343-A8, Edition 12.2017
Conversion into other classes
Ι
sNom
K≈ 1
K ≈ K
SSC
Calaculation see Section above with: K
T depending on power system and specified closing sequence
P
with
with
R
Ct
R
BN
Ι
sN
K
ALF
U
s.t.max
U
al
K
K
SSC
T
P
= 5 A (typical value)
ALF
Knee-point voltage
k
Internal burden resistance
Nominal burden resistance
Secondary nominal transformer current
Rated accuracy limiting factor
Sec. terminal voltage at 20 Ι
Sec. magnetization limit voltage
Dimensioning factor
Factor symmetr. Rated fault current
Primary time constant
Current Transformer Requirements
D.2 Class conversion
≈ K
SSC ALF
pNom
457