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13 Frequency protections "UF", "OF"
The frequency protections record the mains frequency variations above adjustable threshold (f12, t12) below (f13, t13), generating alarm
or the opening the circuit-breaker. fact, the case where the circuit-breaker is
open and current detected, the timing leads the "alarm" state and not "TRIP".
The function active when auxiliary power supply power PR120/V module present (see par.
14.11.N.
The protections work the line voltages. 15. This because the fault linked the voltages can persist
even with the circuit-breaker open and the unit would therefore always under "timing".11.1.
Model 2234 Apparatus Scale
L2778
Doc. therefore defined the following formula:
U=U+U+U
14.9.
Thresholds LC1 and LC2 are expressed percentage I1(current threshold specified for protection while the "warning current" Iwis expressed
as absolute value.
14.B.
14.9.
The minus sign ('-') front the threshold and power indicates reverse power.2.2 Protection "OV"
When the maximum phase voltage exceeds the set threshold U9the protection counts down the preset time interval and then opens. tio fro (V12,V23,V31)
The percentage unbalance therefore calculated: lta ------------------------------------------------1-----—— 23— .2.11.3 Protection "RV"
When the residual voltage exceeds the set threshold U10the protection counts down the preset time interval t10 and then opens.
■ The monitored temperature not visible the display.30 10.
The residual voltage calculated vectorially summing the phase voltages.05xIn
Threshold LC1________________50% 100% step xI1
Threshold LC2_______________ 50% 100% step xI1
From the PR123/P you can associate each the PR120/K PR121/K contacts with configuration (NO NC), delay and any latch.4 Protection "
The disable-type, fixed-time protection trips when for time higher equal time set unbalance detected between two more line
voltages higher than the set threshold. 14.9.4). The threshold voltages indicated refer the line voltage.
A
D isabling the Trip control the protection means that the PR123/P unit could ork, ith the circuit-breaker closed, range
o tem peratures here correct operation the electronics not guaranteed.2).
m (V12,V23, V31)
1 tio rse ctive "
The PR123/P unit provides protection (which can disabled) with adjustable fixed time k), against reverse active power, active both with
self-powering and auxiliary supply.
The protection always active, both with auxiliary supply and self-powering.2.2.00 step 0.9.3.
The current thresholds are lower than those available with the protection that the load control can used prevent tripping due overloads.Na 2
Page No.
When the total reverse active power (sum the power the phases) exceeds the set reverse active power threshold P11the protection counts
down the preset time interval t11 and then opens.
14.9. Range: 90% steps.1 Protection "UV"
When the minimum phase voltage drops below the set threshold U8the protection counts down the preset time interval and then opens.2.
The operating logic involves the activation three contacts when the preset thresholds LC1, LC2 and are exceeded.:
■ the event Warning and Alarm, the display momentarily turned off, preserve its functionality.9.2. This done contactors switch-disconnectors (wired outside the release), controlled the PR123/P means contacts the PR120/
K module the PR021/K external unit.11.2.
Apart from the normal timing and "TRIP" operation, the voltage protections can state defined "alarm" (with the "emergency" led and
an alarm message displayed) providing there auxiliary PR120/V module power supply. The allowable values are given the following table:
Warning current 0. When the circuit-breaker closed the passage of
a current detected, you pass immediately from the state "alarm" "TRIP" without timing (see par.11 Voltage protections "UV", "OV", "RV", "
The PR123/P unit provides voltage protections, which can disabled, with fixed adjustable time k), active both with self-powering and
with auxiliary supply:
- Undervoltage "UV"
- Overvoltage "OV"
- Residual voltage "RV"
- Unbalance line voltage "U".
14.9.10 Load control function
Single loads can enabled/disabled the load side before the overload protection intervenes and trips the circuit-breaker the supply
side.
84/158
. The threshold indicated percentage "Pn", where "Pn"
is the nominal power the circuit-breaker Vn*In).
, ax.
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