L2275
Emax UL
71/132
Doc. N°
Mod.
RH0109002
Apparatus
Scale
Page N°
The protections work on the phase voltages. The threshold voltages indicated refer to the phase voltage.
Apart from normal timing and “Trip” operation, the voltage protections canbe in a state defined as “alarm” (“emergency” LED lit and display of alarm
message), only with an auxiliary power supply. In fact, in the case where the power circuit breaker is open and no current is determined, the timing
leads to the “alarm” state and not to “TRIP”. This is because the fault linked to the voltages can persist even with the power circuit breaker open
(VT always connected) and the unit would therefore always be under “timing”. When closing of the power circuit breaker or the passage of current
is determined, you pass immediately from the state of “alarm” to “TRIP” without timing (for warning see par. 15.3.2).
15.2.6.9.1 Protection “UV”
When the minimum phase voltage drops below the set threshold V
8
, the protection times for the time set t
8
and then opens.
15.2.6.9.2 Protection “OV”
When the voltage phase maximum exceeds the set threshold V
9
, the protection times for the time set t
9
and then opens.
15.2.6.9.3 Protection “RV”
When the residual voltage exceeds the set threshold V
10
, the protection times for the time set t
10
and then opens.
The residual voltage V
0
is calculated by vectorially summing the phase voltages. It is therefore defined by the following formula
3
2
1
0
V
V
V
V
+
+
=
.
The protection allows determination of voltage unbalances in the case of star systems with neutral grounded.
15.2.6.10 Protection against Reverse active power “RP”
The PR113 unit carries out excludable, with fixed adjustable time (t = k) protection against reverse active power, active both with self-supply and
with auxiliary supply.
When the total reverse active power (sum of the power of the 3 phases) exceeds the set threshold of reverse active power P
11
, the protection
times for the time set t
11
and then opens.
The minus sign (‘-’) in front of the threshold and the power indicates reverse power. The threshold is indicated in a percentage of “Pn”, where
“Pn” is the nominal power of the power circuit breaker ( 3 Vn*In).
15.2.6.11 Protection against instantaneous short circuit “Iinst”
This function has a single protection curve with fixed time.
When the protection trips, the power circuit breaker opens by means of the opening solenoid (SA).
15.2.6.11.1 Selection of the threshold value
For correct setting of protection Iinst, linked to the size of the power circuit breaker, work on the relative 10 dipswitches placed on the part above
the trip unit (see figure), consulting the label at the side of them.
The protection, which can only be set by ABB
personnel, cannot be excluded.
In the diagrams of the label, relative to the settings, the
position of the dipswitch is indicated by the white part.
Modification of the threshold set can lead to permanent damage of the power circuit breaker and of the installation itself
with consequent damage to the operator.
15.2.7 Warning functions
15.2.7.1
Warning Threshold
This function allows monitoring of a current threshold Iw which can be set inside the configuration menu (see par.15.4.2.1). The function can be
disabled by selecting [----] (value on “Off”).
When the maximum current (of phase or neutral) exceeds the set threshold, the “warning” LED is lit and the warning message is displayed.
The signaling can be combined with one of the internal relays or with those of the PR020/K unit.
The precision of the threshold is ±10%.
linst setting dip-switch
lins
t se
tting
lab
el
In the diagram at the side, the dipswitch
is set in the high position (Off)
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