Page 60 - Sace Emax 2 Catalogue

3/36 SACE EMA X 2 LOW VOLTAGE AIR CIRCUIT-BRE AKERS

— Extremely Inverse
t
Very Inverse
Standard Inverse 8
Description of protection functions

I

t

U8
UV
t8
V In addition to the protection functions, the following indication and control functions are available to
warn the user that a given condition has been reached. The active indications are always shown on the
t display and are also available by communication on the system bus (with Ekip Com modules) or electri-
cal indication (with Ekip Signalling modules).
U9
OV
t8 t9 Synchrocheck (SC - ANSI 25): the synchronism control function compares the voltages in the modules
V as well as the frequencies and phases of two circuit breakers to which the circuit breaker is connected.
Ekip Touch indicates that conditions have been reached that enable the two lines to be made parallel.
t The function is available with two work modes:
• In systems with both busbars supplied, where synchronism is determined by:
U, f,
UF
f12 1. voltage of the two half-busbars above the Ulive threshold for the set time
2. difference of the module of the two voltages below the threshold ΔU
t12 3. difference in the frequency of the two voltages below the threshold Δf
t12
f 4. difference in the phase of the two voltages below the threshold Δ
5. desirable time for synchronism condition tsyn
t 6. circuit breaker open
• In systems with an out-of-service line (dead busbar), where the synchronism condition is determined
OF
by the concurrence of the following conditions for the tref set time:
f13
1. voltage of the active half-busbar above threshold Ulive
t13 2. voltage of the dead half-busbar below threshold Udead
f 3. circuit breaker open
In both cases, synchronism consent is withdrawn when one of the above conditions is missing and it
has not been less than 200ms from the change of the circuit- breaker condition (when the relationship
mean
has been set).
voltage unbalance
U14 The indication of reached synchronism is available directly as an electrical indication via a contact that
is always supplied with the module. The function can be activated simply by connecting the Ekip Syn-
chrocheck module.
U1 U2 U3

Cyclical direction of the phases (ANSI 47): indicates an alarm through inversion of the phases sequence.
V1
senso ciclico

V3 V2

Power factor (ANSI 78): available with a three-phase threshold, warns when the system operates with a
power factor that is less than the set power factor.

The following protections are also available:
Second time-delayed overcurrent protection (S2 – ANSI 50TD): in addition to the standard protection
S, a second (excludable ) time-constant protection is available that enables two independent thresh-
olds to be set in order to ensure precise selectivity, especially in highly critical conditions.