L2275
Emax UL
87/132
Doc. N°
Mod.
RH0109002
Apparatus
Scale
Page N°
15.4.2.1.1 Adjustment of the neutral
The Neutral protection is normally set to a current value at 50% of the adjustment carried out on the phases.
In some installations, where particularly high harmonics occur, the current circulating on the neutral can be higher than that of the phases.
In the SACE PR113 trip unit, it is possible to set this protection for the following values : I1N = 50% - 100% - 150% - 200% * I1.
In the table below the settable values for adjustment of the neutral are indicated, for the various possible combinations between types of
power circuit breakers and adjustment of threshold I1.
0,4 < I1 < 0,5
0,5 < I1 < 0,66
0,66 < I1 < 1
E1B-A
50-100-150-200%
50-100-150%
50-100%
E2B-A
50-100-150-200%
50-100-150%
50-100%
E2N-A
50-100-150-200%
50-100-150%
50-100%
E3N-A
50-100-150-200%
50-100-150%
50-100%
E3S-A
50-100-150-200%
50-100-150%
50-100%
E3H-A
50-100-150-200%
50-100-150%
50-100%
E3V-A
50-100-150-200%
50-100-150%
50-100%
E4S-A
50-100%
50%
50%
E4H-A
50-100%
50%
50%
E4V-A
50-100%
50%
50%
E6H-A
50-100%
50%
50%
E6V-A
50-100%
50%
50%
Adjustments which can be set for the Neutral protection
Adjustments of the threshold I1 (protection against overload)
15.4.2.2
Modification of protection functions
The basic configuration of the unit must be carried out in EDIT mode.
This paragraph allows the user to program the PR113 unit protection functions implemented. Here only the methods for data programming and
which values can be set are given. For all the other information relative to the technical characteristics of these protection functions, see par.15.2.6.
Following the instructions given in par. 15.2.11.2 and 15.4.1, show the pages for setting the protection functions on the display:
Not respecting the limits at settings of “I
1
” and “Neutral sel.” can damage the power circuit breaker with consequent risks
for the operator as well.
Heading: all the protections, excluding L, T and Iinst, are disabled. For protections S and G, it is also
possible to select the type of curve (t=k or t=k/ti^2).
Select which threshold value to set. The value of this, expressed in Amperes, will also be displayed
automatically at the side of the threshold selection.
Select which trip curve t1 (trip time at 3 x I1) to set.
Select whether to enable or disable operation of protection L with thermal memory.
Set the type of curve (t=k or t=k/I
2
) and the state of the protection (On, Off).
Select which threshold value to set (with I2>I1). The value of this, expressed in Amperes, will also be
displayed automatically at the side of the threshold selection.
Select which trip curve to set.
Select whether to enable or disable operation of protection S with thermal memory (only with curve
type t = k/I
2
).
For protections S, D and G, it is possible to enable or disable operation of the protection with zone
selectivity (only with curve type t = k). At the side, it is also possible to set the selectivity trip time for the
protection.
For protections S, D, I and G, it is possible to select which threshold value of start-up to set (only with cur ve type t=k and
locally at the protection considered). The value of this, expressed in Amperes, will also be displayed automatically at the
side of the threshold selection.
Select the value of the desired curve, according to IEC60255-3 (trip time at 3 x I1)
NB: as alternative to curve t=k/I
2
.
Size power
circuit breaker
