Siemens SIPROTEC 7SJ80

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