UV
t8
V I
SACE TMAX XT UL/CSA LOW VOLTAGE MOLDED CASE C I RCUI T- BRE AKERS UL4 89 AND CSA C2 2 . 2 STANDARDS
3/40
t t
t — Ekip Touch/Hi-Touch Protection functions V V U9 t8 9 OV U U8 t8 t
f12
UF OV
U9
t12
t8 9
f V
OF Overfrequency (ANSI 81H) With a constant trip time (t = k), this trips when network frequency exceeds a set threshold.
t
t
OF UF
f13
f12
t13
t12 t12
nverse e
f
f
nverse
voltage unbalance UF2 & OF2 Second protection against underfrequency and overfrequency (ANSI 81L and 87H) This enables two minimum and maximum frequency thresholds to be set simultaneously. For example, just an alarm can be set for tripping when the first threshold is reached, and the circuit-breaker can be set to be opened when the second threshold is reached. OF
t
t
PE
L1 L2 L3 N
f17
mean
f12 t17 f13
U14
t12
t13
f f
U1 U2 U3 LOAD
RP Reverse active power With a constant trip time (t = k), this trips when the total active power – in the opposite direction of the current exceeds the set threshold.
V1
mean
senso ciclico voltage unbalance
U14
V3
V2
RP
U1 U2 U3
Cos ϕ Power factor 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.
V1
senso ciclico
V3
V2
D Directional overcurrent 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 trip curve (t=k), intervenes with two different time delays (t7bw and t7fw), according to the current direction. In ring distribution networks, it enables the identification and disconnection of the area in which a fault has occurred, while maintaining operation in the rest of the installation. Zone selectivity for protection D This enables the possibility to interconnect more circuit-breakers, so that, in case of a fault, the affected 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. 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.
Generator
LOAD B
LOAD A
Forward power flow
FAULT
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