Protection "I; Start-Up Threshold "I; Protection Against Closing On Short-Circuit "Mcr; Protection "G - ABB Tmax T7 Operating Instructions Manual

3.6.6.

Protection "I"

The protection is enabled/disabled from the menu.
If zone selectivity S is active, output signal ZSO is activated in any case during a trip due to protection I, so as to ensure that the
protection releases on the supply side function correctly.
3.6.6.1.

Start-up threshold "I"

The function behaves in exactly the same way as the protection "S". The function is not available with release PR332/P MM.
3.6.7.

Protection against closing on short-circuit "MCR"

The releases installed in the SACE Emax X1 CB allow protection MCR to be activated, which is useful for protecting the instal-
lation from closing upon short-circuit.
The protection possesses the same functional characteristics as protection I (it uses the same control and trip algorithm) and
functions if the aforementioned protection I is disabled.
If enabled, the protection functions in the presence of Vaux or PR330/V. It activates the moment the CB closes for a time slot that
can be adjusted by the user, after which it deactivates.
This function can be activated through a hand-held PR010/T unit with the SD-Testbus2 communication softwares or through a
remote system via a system bus.
Protection "S" protects against short circuits.
3.6.8.

Protection "G"

Protection G is provided by the protection release via vectorial calculation of the neutral and phase currents. The fault current is
defined by the following formula:
In the case when the circuit does not show any fault, the module of the sum of these currents is always nil; vice versa the value
of the fault current will take on an increasingly large value depending on the size of the fault. This operating mode is enabled by
default.
The protection, which can be disabled, can be the fixed time (t=k) inverse time (t=k/I
The tripping time with inverse time curve is given by the expression: t(s)=
real tripping time is forced to t
NOTES:
- t(s): envisaged tripping time
- I : fault current; given in [In] (example: 0.4In)
f
- I , t : protection G parameters set by the user, given in [In] and [s]
4 4
The minimum threshold setting for protection G is 0.1In for protection releases with SW version ≥ 2.05 (sw ≥ 1.00 per PR332/P MM).
WARNING: Protection G is disabled for current values of over 8In (for I
4In (for 0.2In≤ I <0.5In) and over 2In (for I
4
WARNING: In the absence of Vaux, the minimum threshold setting is 0.25In with rating plug= 400A and 0.2In for
all the other sizes. If the entered value fails to comply with this limitation, the SW overrides the threshold until it
reaches the minimum value accepted and "Configuration" error appears on the display.
WARNING: It is possible to disable the trip control of the protection ("Enable Trip: Off").
In that case, for the whole duration of the unbalance the CB will not be opened, but only the condition will be
signaled by means of the "warning" LED lit up and a warning message.
3.6.8.1.

Start-up threshold "G"

The function behaves in exactly the same way as the protection "S".
3.6.8.2.

Zone selectivity "G"

NOTE: function not available with PR332/P MM.
Zone selectivity "G" can be active at the same time as zone selectivity "S".
Zone selectivity "G" can be active at the same time as zone selectivity "S".
3.6.9.

Protection "Gext"

Also called "Source Ground return", this can be carried out when there is the need to check operation of a machine (transformer,
generator or motor etc.) which has star-configured windings.
The protection is assured by physically positioning an external toroid on the cable connected from the star center of the machine
to the earthing connection point.
The induced current on the winding of the toroid is proportional to the fault current which, in this case, only transits in the above-
mentioned toroid
The presence of sensor SGR must be activated via the menu, in the Settings-Circuit-breaker-Earth Protection section.
The minimum threshold setting for protection Gext is 0.1xIn (the In settings are 100, 250, 400, 800A) with SW version ≥ 2.05.
B0431
Mod.
(t(s)= t ).
4 4
<0.2In).
4
B1751
)
2
. If the calculated value is less than t
≥ 0.8In), over 6In (for 0.5In≤ I
4
Apparatus
Emax X1-Tmax T7-Tmax T8
1SDH000587R0002
Doc N°
, the
4
<0.8In), over
4
Scale
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