B0431
Emax X1-Tmax T7-Tmax T8
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Doc N°
Mod.
Apparatus
Scale
Page No
1SDH000587R0002
3.6.3.2.
Start-up threshold S
The start-up function can be selected in the case where the curve with fixed time is selected.
The start-up function enables the protection threshold (S, I and G) to be changed during a time interval lasting “ts”, starting from
“start-up”. The latter must be intended as follows:
- Passage of at least one of the phase currents above the activation threshold of the adjustable Start-Up with Ekip Connect or
PR010/T (0.1…10In, by 0.1In steps); A new start-up is possible after the current has dropped below this threshold.
3.6.3.3.
Zone S selectivity
NOTE: function not available with PR332/P MM.
The zone selectivity function, guaranteed only if an auxiliary voltage is provided, enables the area of the fault to be isolated, only
isolating the part of plant nearest to the fault, while keeping the rest of the plant operational.
This is achieved by connecting all the zone selectivity outputs (ZSO=K51/SZout) of the protection releases belonging to the same
zone to each other and by conveying this signal to the zone selectivity input (ZSI=K51/SZin) of the protection release immediately
upstream. If the wiring has been done correctly, all the zone selectivity inputs of the last circuit-breakers in the chain and all the
outputs of the circuit-breakers at the head of each chain must be empty.
Area 1
Release
1a
Release
1b
ZsO
ZsO
1a
1b
Release
1
ZsI
1
ZsO
1
Area 2
Area n
Release
2
ZsI
2
ZsO
2
Release
0
ZsI
0
Release
n
ZsI
n
ZsO
n
As a practical example, the figure above shows how a fault on the load side of “Release 1a” will be isolated by this latter without
“Release 1” or “Release 0” being tripped. A fault immediately downstream of “Release 1” will be isolated by this latter without
“Release 0” being tripped, thus ensuring that Areas 2…n remain operative.
The following logical table is implemented to manage the Zone Selectivity Input (ZSI) and Zone Selectivity Output (ZSO) signals:
Zone selectivity
I
f
> I
2
ZSI signal
ZSO signal
Trip T
Excluded
NO
0
0
No trip
Excluded
NO
1
0
No trip
Excluded
YES
0
0
t
2
programmed
Excluded
YES
1
0
t
2
programmed
Inserted
NO
0
0
No trip
Inserted
NO
1
1
No trip
Inserted
YES
0
1
t
selectivity
Inserted
YES
1
1
t
2
programmed
The time t
2
must be set at a value higher than or equal to t
selectivity
+50 ms, on the CB on the supply side, not required on the first
one in the chain.
3.6.4. Protection S2
PR333/P allows two protection S thresholds to be set. They are independent of each other but can be activated at the same time.
This function allows a better selectivity level to be obtained than by using a protection release without “double S”.
WARNING: The zone selectivity function with double S is valid with the t=k time setting
.
I
t
Start-Up Threshold I2
ts
Threshold I2
Activation of Start-Up
Threshold Start-Up activation
B1751
