where
t(G)
is the theoretical operating time constant value of G in seconds
k, c, α
are the constants characterising the selected curve
G
is the measured value of the characteristic quantity
G
S
is the setting value
TMS
is the time multiplier setting
The constants k and c have a unit of seconds, α has no dimension.
There is no intentional delay on reset. The function will reset when G < G
s
.
Curve shapes
Time characteristic:
t(G)
G
S
G
T
G
D
G
MAX
G
S
= I
nom
× LIM
G
T
= 1.1 × G
s
G
MAX
= 2.2 × CT
p
G
T
: Minimum trip current
G
MAX
: Maximum trip current
I
nom
: Nominal current setting
CT
p
: Current transformer primary
GPC-3 DRH 4189340587 UK
Protections
DEIF A/S
Page 97 of 122