WEG GRT7-TH4E User manual

Motors | Automation | Energy | Transmission & Distribution | Coatings
Automatic Voltage Regulator
Regulador Automático de Tensión
Regulador Automático de Tensão
GRT7-TH4E
GRT7-TH4PE
Installation, Operation and Maintenance Manual
Manual de Instalación, Operación y Mantenimiento
Manual de Instalação, Operação e Manutenção

Installation, Operation and Maintenance Manual
Manual de Instalación, Operación y Mantenimiento
Manual de Instalação, Operação e Manutenção
Document # / Nº do documento: MGML07-00136
Models / Modelos: GRT7-TH4E, GRT7-TH4PE
Language / Idioma: English / Español / Português
Revision / Revisión / Revisão: 08
December / Diciembre / Dezembro, 2022

GENERAL INDEX / ÍNDICE GENERAL / ÍNDICE GERAL
Installation, Operation and Maintenance Manual
Pages 7 - 18
Manual de Instalación, Operación y Mantenimiento
Páginas 19 - 29
Manual de Instalação, Operação e Manutenção
Páginas 30 - 41
Português Español English
Apendix A / Apéndice A / Apêndice A
Pages / Páginas 42 - 48

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Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE l 7
FOREWORD
This manual may in no way be reproduced, filed, or transmitted through any type of media, whether
it be electronically, by printing, phonographically or any other audiovisual means without prior
consent from WEG. Infringement is subject to prosecution under the law.
Due to the continuous improvement of WEG products, the present manual may be modified and/or
updated without prior notice which may result in new revisions of the installation and maintenance
manuals for the same product.
WEG reserves itself the right not to update automatically the information included in this manual.
However, customers may at any time request any updated version of the manual, which will be
supplied to them free of charge.
If requested, WEG can supply an extra copy of this manual. The equipment serial number and model
should be informed by the customer, when making the request.
ATTENTION
1. It is necessary to follow the procedures contained in this manual for the warranty to be valid.
2. Qualified personnel must execute the alternator installation, operation, and maintenance.
NOTES
1. The total or partial reproduction of the information supplied in this manual is authorized, if reference is
made to its source;
2. If this manual is lost, an electronic PDF file is available from our website www.weg.net or another
printed copy can be requested.

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Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE l 9
INDEX
1SAFETY INFORMATION ............................................................................................11
2STORAGE INFORMATION.........................................................................................11
3INTRODUCTION .........................................................................................................11
4TECHNICAL CHARACTERISTICS.............................................................................12
5REGULATOR NAMEPLATE.......................................................................................12
6BLOCK DIAGRAM......................................................................................................13
7TRIMPOTS FUNCTION...............................................................................................13
8TRIMPOTS ADJUSTMENT.........................................................................................13
9OPERATION ...............................................................................................................14
9.1 VOLTAGE REGULATOR..................................................................................................................14
9.2 POWER CIRCUIT CONNECTION ....................................................................................................14
9.3 FIELD FLASHING .............................................................................................................................14
9.4 U/F OPERATION ..............................................................................................................................14
9.5 PARALLEL OPERATION FOR TWO OR MORE ALTERNATORS...................................................15
10 CONNECTION DIAGRAMS ........................................................................................16
11 DIMENSIONAL DRAWINGS.......................................................................................16
12 IDENTIFICATION OF CONNECTION TERMINALS ...................................................17
13 DIAGRAM FOR TEST WITHOUT ALTERNATOR......................................................17
14 PROBLEMS, CAUSES AND CORRECTIVE ACTIONS .............................................18
15 PREVENTIVE MAINTENANCE...................................................................................18
16 WARRANTY................................................................................................................18

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Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE l 11
1 SAFETY INFORMATION
To guarantee the safety of the operators, the correct installation and proper operation of the equipment, the following
precautions must be taken:
▪Installation and maintenance services should be performed only by qualified personnel, using appropriate equipment;
▪The product instruction manual and specific product documentation must always be consulted before proceeding with its
installation, handling and parameter setting;
▪Adequate precautions should be taken to avoid drops, knocks and/or risks to the operators and the equipment.
Always disconnect the main power supply and wait for the alternator to come to a complete stop, before touching any
electrical component associated with the equipment including the control connectors. Do not touch the input and output
connectors since high voltages may be present even after the power has been switched off and keep them isolated from
the rest of the main command circuit of the alternator.
2 STORAGE INFORMATION
If the alternator needs to be stored for a brief period before its installation and/or start-up, the following measures should
be taken:
▪The regulator must remain in its original package or in a similar package which provides the same safety conditions
against mechanical damages, excessive temperature, and humidity to avoid rusting of contacts and metallic parts,
damages to integrated circuits or any other damage arising from improper storage;
▪Properly packaged, the regulator must be kept in a dry and well-ventilated area away from direct sunlight, rain, wind, and
other adverse weather conditions to ensure the preservation of its operational functions.
Failure to comply with the above-mentioned recommendations could exempt the supplier of the equipment from any
responsibilities and liabilities from any resulting damages as well as voiding the warranty on the equipment or damaged
part.
3 INTRODUCTION
The GRT7-TH4E/PE automatic analog voltage regulators are compact while featuring high reliability and low cost. They
were designed with state-of-the-art technology for voltage regulation of brushless synchronous alternators.
Their control and regulation circuits use semiconductors and integrated circuits duly evaluated following the most
demanding quality requirements. Mechanical components for field flashing are not required, and its system is completely
solid state and encapsulated in epoxy resin suitable for maritime environments and able to withstand vibrations of up to 30
mm/s. It is fitted with internal voltage adjustment by trimpot and external by potentiometer allowing an alternator voltage
adjustment.
The PID control system is adjusted with two trimpots that adjust the proportional-integral (PI) and deferential (D) gains
allowing a wide adjustment range while allowing operation of the regulator with several types of alternators, and with a
high number of dynamic characteristics. The under-frequency protection set point is adjustable by trimpot, and the nominal
operating frequency can be set to 50Hz or 60Hz by jumper.

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12 l Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE
4 TECHNICAL CHARACTERISTICS
Model
Characteristics
GRT7-TH4E 5A
GRT7-TH4PE 7A
Nominal operating current
5A
7A
Peak Current
7A
10A
Analog input ±10Vdc
±10Vdc (±15%Vsen)
Droop adjustment for parallel operation
Yes
UL certification
Yes
Sensing Input
160-300 Vac or 320-600 Vac (Vsen)
Power supply
160-300 Vac (1or 2)
Rectifier gain ratio
0,45
Output voltage¹
72-135 Vdc
Field resistance @ 20ºC
6 up to 50Ω
Static regulation
0,5%
Adjustable dynamic response
8 up to 500ms
Operating frequency
50Hz or 60Hz
Under Frequency protection (U/F)
Adjustable
Internal voltage adjustment
Adjustable via trimpot, for the entire voltage range
External voltage adjustment
-30% (Vsen) with potentiometer of 5 kΩ
Operating Temperature
-40° to +60ºC
EMI suppression
EMI Filter
Approximate weight
547 g ±5%
Table 4.1: Technical characteristics
5 REGULATOR NAMEPLATE
The example above shows the main characteristics to be followed before installation.
NOTE
The identification nameplate is attached to the bottom of the regulator frame.
¹For an input voltage of 160 Vac, the maximum output voltage obtained is 72 Vdc.
For 300 Vac of input voltage, the output voltage obtained is 135 Vdc, that is, the maximum dc output voltage is equal to
0.45 x the effective alternating voltage input.
Figure 5.1: Regulator Nameplate
Operating Frequency
Model
Power Supply
Excitation Voltage
Rated Current
Sensing Voltage

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Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE l 13
6 BLOCK DIAGRAM
Figure 6.1: Block diagram
7 TRIMPOTS FUNCTION
P1: Voltage adjustment
P2: Droop adjustment
P3: Stability 2 adjustment
P4: Stability 1 adjustment
P5: Under frequency adjustment
8 TRIMPOTS ADJUSTMENT
P1: Rotating CW, voltage increases.
P2: Rotating CW, reactive compensation range increases.
P3: Rotating CW, dynamic response will be slower.
P4: Rotating CW, dynamic response will be slower.
P5: Rotating CW, U/F range increases and rotating CCW, it decreases.
NOTE
* A potentiometer may be connected for fine voltage adjustment (5kΩ/3W) at terminals 6 and 7.
* The P3, P4 and P5 trimpots were set as default and sealed, but if adjustments are required, they can be
performed according to the procedures described in this manual.
Power stage
G
U/F
DROOP
+
+
-
+
Analog input
± 9 Vdc
Reference value
Excitation field
Automatic
field flashing
PID
Sensing

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14 l Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE
9 OPERATION
9.1 VOLTAGE REGULATOR
It compares the actual output voltage from the alternator with the theoretical adjusted value through the trimpot of voltage
adjustment P1, plus the external voltage adjustment (if any). The error is processed by the sensing loop whose value
determines the thyristor firing angle which may vary from 0 to 180°, thus controlling the output voltage of the alternator.
9.2 POWER CIRCUIT CONNECTION
The alternator voltage or the auxiliary winding voltage is connected to the terminals 3 and E3/4. This rectified voltage is
applied, in a controlled fashion, to the alternator exciter field.
9.3 FIELD FLASHING
Generation begins through the residual voltage of the alternator. Once the voltage has reached about 10% of the
nominal voltage, the regulator controls the alternator voltage causing it to rise through the initial ramp in approximately 3
seconds. When the alternator reaches its nominal value, the PID control loop will maintain the alternator output voltage
constant within the adjusted value.
9.4 U/F OPERATION
This operation is determined by trimpot P5, jumper J1 and associated components. The J1 jumper determines the
operating frequency (50 or 60 Hz), following the logic below:
▪J1 closed on 60 Hz = 60 Hz
▪J1 closed on 50 Hz = 50 Hz
Trimpot P5 determines the set point of the U/F mode, which can be from the nominal frequency (Fn) down to 1/3 of Fn,
the value of which comes out of the factory adjusted to 10% below Fn. For operation at 60 Hz it is adjusted to 54 Hz and
for operation at 50 Hz it is adjusted to 45 Hz (see Figure 9.1), the value of which can be changed based on each
application requirements.
Figure 9.1: U/F operation
Output voltage (Vac)
Frequency (Hz)
Output voltage (Vac)
Frequency (Hz)
45
U
n
U/f
50
54
U
n
U/f
60

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Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE l 15
9.5 PARALLEL OPERATION FOR TWO OR MORE ALTERNATORS
The reactive compensation method applied is called a phasor diagram (see Figure 9.2), however, its use depends on each
application. Through this diagram, the alternator output voltage signal is measured and compared with the alternator
current voltage. The result of this interaction introduces a sensing error of the actual voltage signal, causing an increase
or a decrease in the alternator voltage, thus maintaining the reactive between the alternators within acceptable values.
The adjustment of this compensation is made through trimpot P2.
In addition to this operating mode in parallel with other alternators, it is also possible to adjust the reactive by varying the
analog input when this signal comes from a controller capable of, through a control loop, controlling the voltage value at
the analog input and thus varying the armature voltage in order to change the reactive to be shared and compensated in
the network of connected alternators.
Figure 9.2: Phasorial diagram
According to the phasor diagram, the sensing voltage is influenced by the current coming from phase S, which is added to
the voltage of phases R and T. The influence is small in module and large in phase, which means that there is good
compensation for reactive loads and a small influence with active loads.
The current transformer (CT) for reactive compensation must be in phase S of the alternator, and the voltage sensing
signal must be in phases R and T.
To make sure the compensation is in the proper direction, proceed as follows:
▪Operate the alternator by itself (isolated from the grid) and apply a resistive load with about 20% of the alternator capacity;
▪After completely rotating the P2 trimpot clockwise (CW), the alternator voltage should decrease.
Rotating back the trimpot completely CCW, alternator voltage should then increase; If this occurs, the CT polarity is correct.
Otherwise, the CT should be inverted.
When several alternators are connected in parallel, this procedure is required to ensure that all the CT’s are properly
polarized.
To ensure the correct polarization of TC, Inductive Resistive loads must be applied, and the system checked for good
response as below.
Resistive Loads: It will not present compensation with resistive load, keeping the excitation current and alternator voltage
constant in the value adjusted via trimpot Vad. In case of compensation, it indicates that TC is in the wrong phase.
Inductive Loads: With inductive load application, it shall present negative compensation, decreasing the excitation current
corresponding to the gain adjusted in the trimpot droop (0 to 15% voltage adjusted in the Vad). If the compensation is
positive, it indicates the TC is inverted.
Capacitive Loads: With application of capacitive loads, it will present a positive compensation, increasing the excitation
current corresponding to the gain adjusted in the trimpot droop (0 to 15% voltage adjusted in the Vad). If the compensation
is positive, it indicates the TC is inverted.
▪Accuracy class of 0,6C12,5;
▪Window or bar type;
▪Transformer ratio will be in/5A or In/1A, where In/xA is the ratio of the TC primary. Ex.: 100/5A, 150/5A, 100/1A;
▪The secondary current can be 5A or 1A, connecting correctly to terminals S2/5A or S2/1A, respectively. Ex: TC 200/1A,
connect the S1 of the CT to the S1 of the regulator and the S2 of the CT to the S2/1A of the regulator;
▪The current in TC primary must be 20% bigger than the nominal current of the alternator;
▪The CT operation frequency must be equal to the alternator frequency;
▪The CT isolation voltage class must be bigger than the alternator output voltage;
▪The CT must support 1.2 x In.
▪The TC is not supplied by WEG.
RT
R
T
IS
S

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16 l Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE
10 CONNECTION DIAGRAMS
The connection diagrams are attached (Appendix A) and must be followed according to the electrical connections of
alternator that is represented in this document. For different internal connections of alternator from the representation
below, consider the connection from alternator manufacturer. The connection pins are showed below:
Figure10.1: Connection pins’ identification
ATTENTION
1. Before connecting the regulator to the alternator, check installation manual and the nominal reference
voltage;
2. If the reference voltage is not equal to the alternator output voltage, do not make the connections
without first contacting the service department.
11 DIMENSIONAL DRAWINGS
Figure 11.1: Dimensional (mm)
Overview
Front view

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Automatic Voltage Regulator –GRT7-TH4E / GRT7-TH4PE l 17
12 IDENTIFICATION OF CONNECTION TERMINALS
E1: Sensing Voltage (160 up to 300Vac).
E2: Voltage (320 up to 600Vac).
3: Power supply.
E3/4: Sensing Voltage.
S1: Connection for pole S1 of the CT.
S2/5A: Connection for pole S2 of the CT, ratio In/5A.
S2/1A: Connection for pole S2 of the CT, ratio In/1A.
6 e 7: Connection for potentiometer 5kΩ/3W.
F+, F-: Connection for alternator field.
J1: Jumper 50 Hz or 60 Hz.
A+, A-: Analog input voltage ±10 Vdc.
13 DIAGRAM FOR TEST WITHOUT ALTERNATOR
Below is the diagram for regulator connection on the bench where the equipment operation may be verified before
connection to the alternator.
Material required:
- 1 Small screwdriver;
- 1 Incandescent lamp;
- 1 Lamp socket;
- 1 Bipolar breaker (5A recommended);
- 1 Extension cable;
- 1 Power Plug 220 Vac.
NOTE
1. After performance of such steps as per the procedure the equipment must be sent for evaluation by WEG
technical support.
1º. Assemble the circuit according to the diagram in figure 13.1;
2º. With small screwdriver, turn trimpots Vad and U/F counterclockwise until the end of stroke;
3º. Turn on circuit breaker:
4º. Turn slightly the trimpot Vad clockwise (the lamp must shine after certain position of trimpot)
5º. With lamp on, turn slightly the trimpot Vad counterclockwise (after certain position of trimpot, the lamp must turn off);
6º. Turn off the circuit breaker.
Figure 13.1: Test diagram

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14 PROBLEMS, CAUSES AND CORRECTIVE ACTIONS
Table 14.1
Problems
Causes
Corrective Actions
There is circulation of reactive power
between alternators when operating in
parallel.
▪Phases sequence (R-S-T) incorrectly
connected;
▪CT connections are inverted;
▪Droop adjustment excessively low.
▪Connect phase sequence correctly.
▪Correctly polarize the CT in the phase shown
below:
▪Increase droop adjustment, rotating trimpot
P2 clockwise (CW).
Generated voltage decreases when load is
applied, and it does not return.
▪Dropping speed of the driving machine;
▪Under frequency protection engaged.
▪Correct speed regulation.
▪Adjust Under frequency protection by rotating
trimpot P5 clockwise (CW).
Alternator voltage does not increase.
▪Residual voltage excessively low.
▪Inverted F+ and F- terminals.
▪Terminals F+ and F- are inverted.
▪With the regulator switched- on, use external
battery (12Vdc) to force excitation (*).
▪Invert F+ and F-.
▪Invert F (+) and F (-).
Generated voltage oscillates at no load.
▪Dynamic not well adjusted.
▪Alternator excitation voltage excessively
low.
▪Adjust trimpots P3 and P4;
▪Check the polarity of the F+ and F-
connection in relation to the generator field
cables.
▪Insert 10Ω/100W resistor in series with field.
Voltage oscillates at a specific load point.
▪Third harmonic of the auxiliary coil is
high.
▪Eliminate auxiliary coil and proceed with the
connections according to the diagrams of
pages 44, 45 or 46.
Voltage surges.
▪Lack of sensing.
▪Faulty electronic circuit.
▪Sensing voltage incompatible with
regulator.
▪Check if alternator phases are present in the
sensing.
▪If the regulator is encapsulated, replace it.
(*) For battery diesel generator where the alternator neutral is grounded battery should always be used independently.
15 PREVENTIVE MAINTENANCE
Periodical inspections of the equipment are required to ensure they are clean, dust and moisture free. It is essential that
all terminal and connections are kept free from corrosion.
16 WARRANTY
See Installation and Maintenance Manual for WEG Alternators.
WEG Group - Energy Business Unit
Jaraguá do Sul - SC - Brazil
Telefono: 55 (47) 3276-4000
[email protected]
www.weg.net
P1
P2
S1
S2
Alternator
Load

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Regulador Automático de Tensión –GRT7-TH4E / GRT7-TH4PE l 19
PREFACIO
Esta publicación no podrá en ninguna hipótesis ser reproducida, almacenada o transmitida a través de algún
tipo de medio, sea electrónico, impreso, fonográfico o cualquier otro posible medio audiovisual, sin la
autorización previa de WEG Industrias S.A. Los infractores estarán sujetos a las penas previstas en la ley.
Esta publicación podrá ser alterada y / o actualizada y podrán resultar en nuevas revisiones de los manuales
de instalación, operación y mantenimiento, teniendo en vista el continuo perfeccionamiento de los productos
WEG.
La WEG se reserva el derecho de la no-obligatoriedad de actualización automática de las informaciones
contenidas en estas nuevas revisiones. No obstante, eso, y en cualquier momento el cliente podrá solicitar
material actualizado que le será provisto sin cargos resultantes.
En caso de pérdida del manual de instrucciones, la WEG podrá proveer ejemplar separado y caso fuera
necesario, informaciones adicionáis sobre el producto. Las solicitaciones podrán ser atendidas, siempre que
sea informado el número de serie y modelo del equipo.
ATENCIÓN
1. Es imprescindible seguir los procedimientos contenidos en este manual para que la garantía tenga
validez;
2. Los procedimientos de instalación, operación y mantenimiento del alternador deberán hacerse por
personal calificado.
NOTAS
1. La reproducción de las informaciones de este manual, total o en partes, se permite desde que la fuente
sea citada;
2. Si se extraviar este manual, el archivo electrónico en formato PDF está disponible en el sitio
www.weg.net o podrá ser solicitada otra copia impresa.