PNI SVM-10K User manual

PNI SVM10K/ PNI SVT10K
Three-phase voltage stabilizer / Stabilizator de tensiune trifazat
EN User manual ......................................................... 3
RO Manual de utilizare ............................................. 13

3User manual
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Introduction
The voltage stabilizers PNI SVM-10K and PNI SVT-10K are designed to
stabilize the output voltage. When the input voltage from the electrical network
fluctuates, the voltage stabilizer will automatically adjust the voltage as close as
possible to the preset value.
These stabilizers have high capacity, high eciency, no waveform distortion
and automatic voltage regulation, so that the connected devices can work
correctly.
PNI servomotor voltagestabilizers havea widerangeofapplications.Depending
on their capacity, they can connect: electromechanical equipment, industrial
equipment, air conditioners, televisions, household appliances, electric tools,
refrigerators and, in general, electronics that need stable voltage.
Structure
The voltage stabilizer includes a phase compensation transformer,
a phase adjustment transformer, an isolation transformer, a
contact system with electric brush, housing and control panel.
The case is closed, with good heat dissipation. The control panel is easy to read
with precise indications.
Operating principle
Three-phase power compensation voltage stabilizers are composed of a three-
phase compensating transformer, three-phase regulating transformer, voltage
detection unit (TUV), servo motor control unit and protection circuit.
The electrical operation scheme is presented in Fig. 1.

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Fig 1. Electrical operation diagram of the voltage stabilizer with automatic
compensation:
The primary winding of the TUV regulation transformer is connected in the
form of a Y. It is connected to the output terminal of the voltage stabilizer. The
secondary winding is connected with the primary winding of the compensation
transformer (TB).
The operating principle of the compensation transformer TB can be found in
Fig 2.
Fig 2. Scheme of the single-phase compensation circuit:
The impedance drop of the compensation transformer is calculated as follows:
Uao= Uai+ Uac
Ui = A-phase Input voltage of the voltage stabilizer
Uao = A-phase Output voltage iof the voltage stabilizer
Uac = A-phase Compensation voltage of the voltage stabilizer
The principle is: When the voltage of phase A increases by ΔUai, ΔUac of the
compensation voltage Uac will change accordingly; and when Uac is equal to

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Uai, the output voltage in phase A Uao is kept constant. Phases B and C follow
the same principle.
Voltage stabilization procedure
When the unit that measures the input voltage detects a variation outside
the preset range, it will send a signal to the control unit that will activate the
servomotor. The secondary voltage transformer will change the polarity and
magnitude of the compensation voltage and control the output voltage within
the preset range.
Basic components
Compensation transformer
When the polarity and magnitude of the voltage increase on the primary coil,
the secondary coil, which is connected in series with the load loop, will produce
a compensating voltage with the necessary changes.
Regulation transformer
The regulating transformer is a three-phase transformer that will automatically
regulate the secondary voltage. It has three electric brushes that slide
symmetrically and automatically. Using a chain to drive the electric brush to
slide along the cylindrical solenoid of the transformer, the servo motor adjusts
the secondary voltage accordingly so that the compensation voltage is kept
constant.
Servo motor control circuit
The servomotor has two control modes: manual and automatic, which can be
selected using a switch.
In manual operation, press the voltage increase button if you want to increase
the output voltage and press the voltage decrease button if you want to reduce
the output voltage, so as to set the required output voltage. In the manual
version, the voltage stabilizer does not work automatically.

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When the automatic option is selected, the voltage increase/decrease can be
automatically detected by the detection unit and the required voltage will be
set.
Detection and adjustment unit of the three-phase voltage stabilizer
The control transformer detects the voltage from the output terminal of the
voltage stabilizer.
When the voltage is between the preset upper and lower limits, all the contacts
of the control relays are in the “OFF” position.
When the voltage exceeds the upper reference limit, the control relay and the
contact relay will activate.
The servo motor works to adjust the compensation voltage and to stabilize the
output voltage. In other words, when the output voltage exceeds the allowed
value (set voltage range), the voltage detection unit will send a command to
adjust the output voltage until it reaches the set value. The nominal voltage is
regulated by the stabilizer potentiometer.
Three-phase protection circuit
The QA automatic switch protects the circuit from overload and short circuit.
The limit switches OLSI and QLS2 form the current protection circuit. When
the electric brush touches the solenoid, the voltage regulation relay will be
disconnected from the power source, stopping the servo motor, thus protecting
the circuit.
The normally closed contact of the relay is closed while the over and under
voltage protection circuit is in normal operation. When the signal voltage
exceeds the set value or falls below the set value, the normally closed contact
of the relay will be activated, the circuit will be interrupted and the automatic
compensation system will not work. The set value of the overvoltage is
approximately 420V, and the set value of the undervoltage is 320V.
Phase sequence error protection circuit or lost phase
When one of the phases of the three-phase power supply is mismatched or the
phase is lost, the light indicator of the phase sequence protector will be o, and
the whole device will be in automatic protection state.

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The stabilizer has two control boards, named A and B. If there is a malfunction
on control board A during operation, the switch to control board B can be
activated manually, which will work instead of the board. A.
Single-phase voltage stabilizer detection and adjustment unit
The operating principle of the detection and adjustment unit of the single-
phase voltage stabilizer is the same as the three-phase voltage stabilizer.
The QA automatic switch protects the circuit from overvoltage and short
circuit. The automatic voltage compensation system is set with overcurrent
protection.
When the electric brush hits the limit switch, the normally closed contact will
be interrupted and the servo motor will stop.
When the overvoltage protection circuit is in normal working condition, the
normally closed contact of the control relay is closed. When the voltage
exceeds the set value, the normally closed contact of the control relay will be
interrupted and the control circuit together with the automatic compensation
system will stop working.
Operating conditions
Voltage stabilizers are only used indoors, taking into account the following
requirements:
• Operating temperature: -26°C ~ +80°C
• Altitude: < 1000 m above sea level
• Humidity: ≤ 90%
• There must be no gases, vapors, chemicals or explosive substances, excess
dust, excess humidity in the work space.
• The surface on which the stabilizer is installed must be flat, without
vibrations.
• For installation under special conditions, ask for specialist advice.

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Technical specifications
Model PNI SVM-10K PNI SVT-10K
AC input
Voltage range 277 V ~ 433 V
Frequency 50 / 60 Hz
Phase Three-phase + N + G
AC ouput
tension 380 V / 400V
Precision voltage
regulation ≤ ±3 %
Wave form Sine wave
Eciency ≥ 96%
Capacity 10KVA
Maximum load 8000W
Current 34.8A
Power factor 0.8
Distortion No wave form distortion
Overload protection 433 V ±5 V
Undervoltage
protection 316 V ±5 V
Other protections Start-up delay, mechanical error, overcurrent,
short circuit, overtemperature
Other
Working temperature -26°C ~ +80°C
Altitude < 1000 m above sea level
Humidity ≤ 90%
Dimensions 410 x 240 x 370 mm 310 x 345 x 720 mm
Maintenance
To ensure operation in optimal conditions for a long period of time, follow the
following instructions:

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• do not block the ventilation slots of the stabilizer
• periodically clean the stabilizer housing of dust
• check the input and output cables if they are correctly connected and if
they are in good condition
• check that the stabilizer does not have condensation on the housing.
Troubleshooting
In case of improper operation of the voltage stabilizer, before calling a specialized
service center, check the following:
• check the power cable of the stabilizer and the power cable of the device
connected to the stabilizer.
• check the starting power of the device connected to the stabilizer. It is
recommended that this does not exceed 80% of the nominal power of the
stabilizer. If it exceeds this threshold for a long time, it is recommended to
increase the ventilation capacity of the stabilizer.
• If there is a power failure while the stabilizer and the consumers are working,
after the power returns, gradually connect the consumers.
Installation and connection
The three-phase wires A, B and C of the power supply must be drawn from the
lower part of the case through the current transformer and connected to the
terminals of the air switch in the case.
Each connection terminal marked “output voltage” must be connected to the
load. The type of connection wire is at the user’s choice depending on the load.
In general, it should be the same as the input cables.
The gauge of the grounding wire must be according to the specifications of
the local power supply authority. The earthing cable must be connected to the
head of the pillar marked with “earthing cable”. The resistance of the earthing
cable should be less than 0.42.
Grounding examination
It is important that the troubleshooter carefully checks the connection wires,

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so as to ensure the reliable operation of the voltage stabilizer. The details are
as follows:
• Check the main loop connection wire to see if it is properly connected
and if the universal switch connection wires are in position. Tighten well if
it gets weak.
• Check the contact wires of all types of electrical devices behind the panel,
such as the voltmeter, ammeter, switch and see if they are connected
correctly. Tighten well if they get weak.
• Check the circuit board to see if the connecting wires of each point are
connected correctly. You should tighten them if they are loose.
• Check the servomotor on the voltage regulator and see if the connection
wire of the limit switch is in order. You should tighten it if it is weak.
• Check the control circuit board and power switch C45, which controls the
power supply to the electric motor in the control box, and see if they are
closed.
Electrical operation and troubleshooting
1. Move the “Manual/Automatic” switch to the “Manual” position.
2. Move the knife switch to the “Voltage Stabilization” position; the voltage
of the stabilizer is in the state of zero load.
3. Turn on the power supply, close the QA switch, and at this moment, the
light indicator of the three-phase power source on the panel will light up.
The input voltage is displayed.
4. Press the “Voltage Stabilization” button, and after 5-15 seconds, the delay
relay will be closed, which causes the output contactor to be electrified
and closed. The green light for “Voltage Stabilization” is on. Then, press
the “Voltage Step-up” or “Voltage Step-down” button, and the output
voltmeter indicator will increase or decrease accordingly; thus completing
the manual voltage adjustment test.
Note:
If the voltage stabilizer cannot start and the indicator LEDs of the phase
sequence protector are not lit after pressing the “Voltage stabilization” button,
it means that the phase sequence is connected incorrectly. To fix this problem,
you must first turn o the power supply and then change either of the two
wires.
After pressing the “Voltage stabilization” button, the voltage stabilizer will have