F&F PF-421 TRMS User manual
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PF-421 TRMS
Automatic phase switch with
the adjustable lower and upper
voltage threshold
The PF-421 automatic phase switch is used to maintain the con-
tinuity of the power supply of a single-phase receiver in case of
phase failure or when the phase exceeds preset parameters. The
compact size of the device allows you to save space in the elec-
trical cabinet.
By measuring the RMS value of the voltage (True RMS),
the switch guarantees the correct operation even when
operating with a severely disturbed power supply net-
work.
A three-phase voltage (3×230 V+N) is connected to the input ter-
minals of the device. A single-phase voltage (230 V) of one of the
phases appears at the output of the relay. The electronic circuit
of the switch controls the voltage values of the supplied phases
so that the output voltage is not lower or higher than the set
Purpose
Functioning
F&F Filipowski sp. j.
Konstantynowska 79/81, 95-200 Pabianice, POLAND
phone/fax (+48 42) 215 23 83 / (+48 42) 227 09 71
www.fif.com.pl; e-mail: biuro@fif.com.pl
Do not dispose of this device in the trash along with other waste!
According to the Law on Waste, electro coming from households free of charge and can
give any amount to up to that end point of collec� on, as well as to store the occasion of
the purchase of new equipment (in accordance with the principle of old-for-new, regar-
dless of brand). Electro thrown in the trash or abandoned in nature, pose a threat to the
environment and human health.
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values. The phase with the correct parameters is directed to the
output Switch. The device measures the RMS value (True RMS)
of the voltage, so it is perfect for modern automation systems,
where the supply voltage is often distorted due to the operation
of nearby devices with pulse power supplies. The corresponding
green LED light indicates that the phase is connected to the out-
put of the switch. Depending on the set mode of operation, pha-
se L1 is the priority phase, or the system operates without phase
priority (Tret set to ∞ ).
Operating with the priority phase
In this mode, the L1 phase is the priority phase and if its pa-
rameters are correct for the time set by the Tret knob, it will be
connected to the output. If the L1 phase exceeds the upper or
lower settings level (its voltage value will be incorrect), then the
voltage of the L2 phase (if it has the correct parameters) will be
connected to the output, or the L3 phase, if the L2 phase was
also incorrect. If phase L3 is connected to the output and phase
L2 returns to the correct parameters, and will be correct for the
time set by the Tret knob, then it will be switched to the output
(priority of phases from highest to lowest is L1, L2, L3). If the
output phase voltage is 10 V below the set value or 10 V above
it, the switchover will occur with a 10-second delay. If the phase
value goes beyond this range, it will be disconnected immediate-
ly (about 200 ms).
Operating without the priority phase (Tret set tos ∞ ).
In this mode, all phases have the same priority, which means
that the first of the correct phases will be connected to the out-
put (when the power is switched on, the check starts from phase
L1). The output phase will be changed only when the voltage at
the output exceeds the range set by the Vmin and Vmax knobs.
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If the output phase voltage is 10 V below the set value or 10
V above it, the switchover will occur with a 10-second delay. If
the phase value goes beyond this range, it will be disconnected
immediately (about 200 ms).
In both cases, when the voltage of either phase is not in the cor-
rect range, the output load is disconnected. Switching the out-
put to a phase with incorrect parameters is not possible.
The operating voltage range for all three phases is set using the
Vmax and Vmin knobs. The Vmax knob determines the maxi-
mum allowable output voltage, while Vmin determines the min-
imum voltage. If the phase voltage value is between the Vmin
and Vmax thresholds, it is considered normal.
Incorrect connection of the input wires (N connected
in the wrong place) will switch the leads at the output,
which means that in the place where the N potential
should appear the phase voltage connected to the N
input terminal will appear. The N potential will appear
where the potential of the selected phase should ap-
pear. If the voltage of the phase connected to the N
terminal is incorrect, the output will be completely dis-
connected, but the potential of the incorrectly connect-
ed phase will still be present at the output!
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Time courses
Without the priority phase
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With the priority phase
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1.Turn off the power supply.
2.Connect the input voltages to terminals 1, 2, 3 and the neutral
wire to terminal 4.
3.Connect the powered single-phase circuit to terminal 5 or 6
(phase) and 7 or 8 (neutral wire).
4.Turn on the power supply and check the continuity of the pow-
er supply to the connected single-phase circuit by successively
turning off the voltage in phases L1 and then L2.
Front description
Mounting
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1 power supply input – phase L1
2 power supply input – phase L2
3 power supply input – phase L3
4 power supply input – neutral wire
5/6 power supply output – phase L’
7/8 power supply output – neutral wire
Wiring diagram
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Outputs 5-6 and 7-8 are connected in parallel, which
means that the output signal is available on each output.
power supply voltage 3×230 V+N
minimum operating voltage
(with power from a single phase) 85 V
maximum phase voltage 420 V
frequency 45÷55 Hz
cooperation with power generators no
maximum load current (AC-1) 16 A
mechanical strength of contacts 1×10⁷
electrical strength of contacts (16 A/AC-1) 1×10⁵
TrueRMS measurement yes
sampling frequency of the signal 4 kHz
actuator 3× relay
return hysteresis 10 V
setting range Vmin 160÷220 V
setting range Vmax 240÷280 V
voltage measurement error ±1%
switching time max 200 ms
return time 5÷300 s
indication of the output voltage 3×LED
power consumption 1.5 W
terminal 4.0 mm² screw terminals
tightening torque 0.5 Nm
working temperature -25÷50°C
dimensions 2 modules (35 mm)
mounting on TH-35 rail
ingress protection IP20
Technical data
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F&F products are covered by a 24-month warranty from the date
of purchase. The warranty is only valid with proof of purchase.
Contact your dealer or contact us directly.
F&F Filipowski sp. j. declares that the device is in conformity
with the essential requirements of The Low Voltage Directive
(LVD) 2014/35/EU and the Electromagnetic Compatibility (EMC)
Directive 2014/30/UE.
The CE Declaration of Conformity, along with the references to
the standards in relation to which conformity is declared, can be
found www.fif.com.pl on the product subpage.
Warranty
CE declaration
E221010
Table of contents
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