Page 76 - SACE Tmax XT - Catalogue

t
Extremely Inverse
Very Inverse
Standard Inverse
t
UV
U8
t8
t
U9
OV
t8 t9 V I 8
3/42 V SACE TMAX XT LOW VOLTAGE MOLDED CASE CIRCUIT-BREAKERS
t
— f12 UF
Ekip Touch/Hi-Touch
Extremely Inverse t12
t12
Very Inverse
Standard Inverse f
Protection functions
t t PE L1 L2 L3 N
l1
OF
f13
l3
t13
I LOAD f
RP Reverse active power
t
l1 With a constant trip time (t = k), this trips when the total active power – in the opposite direction of the current
mean
exceeds the set threshold.
voltage unbalance
U14
I U1 U2 RP
U3
t Cosϕ Power factor
V1
Available with a three-phase threshold, this provides a warning when the system operates with a power
factor that is lower than the set power factor.
senso ciclico
I V3 V2

t D Directional overcurrent
Generator
This form of protection is able to recognize the direction of the current during the fault period and thus
detect if the fault is upstream or downstream of the circuit-breaker. The protection, with a fixed time
LOAD B
l3 trip curve (t=k), intervenes with two different time delays (t7bw and t7fw), according to the current di-
rection. In ring distribution networks, it enables the identification and disconnection of the area in
I LOAD A
Forward which a fault has occurred, while maintaining operation in the rest of the installation.
power flow FAULT
Zone selectivity for protection D (ANSI 68)
t
This enables the possibility to interconnect more circuit-breakers, so that, in case of a fault, the af-
fected area can be disconnected nearest to the fault and operation in the rest of the installation is
maintained. It is possible to enable directional zone selectivity alternatively to zone selectivity of S and
G protections. This also works in the presence of an auxiliary supply.

I Start-up function for protection D
This enables higher trip thresholds to be set at the outgoing point, as available for protections S, I and G.
t l1
t1
l2
t2 RQ Loss of field or reverse reactive power (ANSI 40 or 32RQ)
t4 Q
l3 With a constant trip time (t = k) this circuit-breaker trips when the total reactive power absorbed by
l4 the generator exceeds the set threshold. It is possible to select a constant threshold (k=0) or a
I P
function of the delivered active power of the generator (k≠0).
TRIP
t l1
t1
l2
t2
l3
I
t l1

t1
t4
l3
l4
I