WEG GRT7TH4 R2 User manual

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Motors | Automation | Energy | Transmission & Distribution | Coatings
Automatic Voltage Regulator
GRT7-TH4-R2
Regulador Automático de Tensión
GRT7-TH4-R2
Regulador Automático de Tensão
GRT7-TH4-R2
Installation, Operation and Maintenance Manual
Manual de Instalación, Operación y Mantenimiento
Manual de Instalação, Operação e Manutenção

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Installation, Operation and Maintenance Manual
Manual de Instalación, Operación y Mantenimiento
Manual de Instalação, Operação e Manutenção
Document # / Nº do documento: 10001284109
Models / Modelos: GRT7-TH4 R2
Language / Idioma: English / Español / Português
Revision / Revisión / Revisão: 05
February / Febrero / Fevereiro, 2014

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GENERAL INDEX / ÍNDICE GENERAL / ÍNDICE GERAL
Installation, Operation a
nd Maintenance Manual
Page 7 - 30
Manual de Instalación, Operación y Mantenimiento
Páginas 31 - 54
Manual de Instalação, Operação e Manutenção
Páginas 55 - 77
Português Español
Englsih

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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 absolutely necessary to follow the procedures contained in this manual for the warranty to be
valid.
2. The generator installation, operation and maintenance must be executed by qualified personnel.
NOTES
1. The total or partial reproduction of the information supplied in this manual is authorized, provided
that 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.
WEG EQUIPAMENTOS ELÉTRICOS S.A.

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INDEX
1SAFETY INFORMATION......................................................................................................................................11
2STORAGE AND TRANSPORT............................................................................................................................11
3INTRODUCTION ..................................................................................................................................................11
4TECHNICAL CHARACTERISTICS .....................................................................................................................12
4.1 NOMENCLATURE FOR REGULATORS..................................................................................................................13
4.2 PROTECTIONS – U/F OPERATION.........................................................................................................................14
4.3 BLOCK DIAGRAM....................................................................................................................................................15
4.4 PARALLEL OPERATION OF TWO OR MORE GENERATORS ..............................................................................16
4.5 ANALOG INPUT.......................................................................................................................................................16
5PROTECTION FUSE............................................................................................................................................17
6STANDARDS.......................................................................................................................................................17
7IDENTIFICATION TAG.........................................................................................................................................18
8TRIMPOT FUNCTIONS .......................................................................................................................................18
9CONNECTION DIAGRAMS.................................................................................................................................19
9.1 GENERATOR CONNECTION WITHOUT AUXILIARY COIL....................................................................................19
9.2 GENERATOR CONNECTION WITH AUXILIARY COIL...........................................................................................20
10 CONNECTION DIAGRAM FOR CROSSCURRENT TYPE PARALLEL OPERATION...................................22
11 INTERNAL CONNECTION DIAGRAM ..............................................................................................................23
12 DIMENSIONS.....................................................................................................................................................23
13 FIRST USE.........................................................................................................................................................24
13.1 DESCRIPTION OF THE CONNECTION TERMINALS...........................................................................24
13.2 STEPS FOR CONNECTION...................................................................................................................24
14 TURNING OFF...................................................................................................................................................25
15 REFERENCE OF THE PRINTED SYMBOLS ...................................................................................................25
16 DIAGRAMS FOR TESTING WITHOUT A GENERATOR.................................................................................26
17 TROUBLES, CAUSES AND CORRECTIVE ACTION ......................................................................................28
18 PREVENTIVE MAINTENANCE.........................................................................................................................28
19 WARRANTY.......................................................................................................................................................28

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1 SAFETY INFORMATION
Toguarantee 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.
Do not touch inlet and outlet connections, and always keep them isolated from the rest of the panel command circuit, except
when otherwise instructed.
Always disconnect the main power supply and wait for the generator 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 principal
command circuit of the generator.
The equipment’s electronic boards can have components that are sensitive to electrostatic discharges. Do not directly touch
components or connections. If this is absolutely necessary, then first touch the grounded metal body or use an appropriately
grounded bracelet.
2 STORAGE AND TRANSPORT
If the generator needs to be stored for a short period of time 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 so as 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 in order 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-TH4 R2 automatic analog voltage regulators are compact products featuring high reliability and low price, which were
designed with state-of-the-art technology for voltage regulation of brushless synchronous generators.
Their control and regulation circuits use semiconductors and integrated circuits duly tested following the most demanding quality
requirements. It doesn’t utilize mechanical components for field flashing since its system is completely static. It is encapsulated
in resin suitable for maritime environment and withstands vibrations up to 5Gs. It is fitted with internal voltage adjustment by
trimpot and external by potentiometer.
The stability of the system is controlled through trimpots that adjust proportional and integral gains, allowing a wide adjustment
range and permitting the operation of the regulator with several types of generators, covering a large number of dynamic
characteristics.
It features under frequency protection (U/F limiter which does not permit that the generator to be excited during the turn off
procedures or with a rotation decrease), whose intervention point is adjustable by trimpot, and the rated operation frequency
can be configured for 50Hz or 60Hz operation.

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4 TECHNICAL CHARACTERISTICS
Table 4.1 - Mechanical and electrical characteristics.
Models
Characteristics
GRT7-TH4 R2
5A AM/220M GRT7-TH4 R2 5A EM/220M GRT7-TH4 R2 5A GM/110M GRT7-TH4 R2 7A AM/220M GRT7-TH4 R2 7A EM/220M GRT7-TH4 R2 7A GM/110M
Nominal field current
5A 5A 5A 7A 7A 7A
Nominal current with
forced ventilation 7A 7A 7A 10A 10A 10A
Peak current (max.
1min) 7A 7A 7A 10A 10A 10A
Protection fuse for
power supply 3A 3A 3A 5A 5A 5A
Sensing (selected
via jumper cable)
(V
Ral
)
160-300 or
340-570 Vac 180-240 or 515-660 Vac 85-140 or 170-280 Vac 160-300 or 340-570 Vac 180-240 or 515-660 Vac 85-140 or 170-280 Vac
External voltage
control Through 5K/3W potentiometer.
Sensing power
supply Single Phase.
Power Supply
Range (V
al
) 170 to 300Vac 93 to 126 Vac 170 to 300Vac 93 to 126 Vac
Power supply
curren. Single Phase
Rectifier gain ratio
(K
c
) 0,45.
Maximum field
voltage (Vf) 76,5 Vdc (Val mín), 112,5 Vdc (Val máx).
41,8 Vdc (Val
mín),
56,7 Vdc (Val
máx).
76,5 Vdc (Val mín),
112,5 Vdc (Val máx).
41,8 Vdc (Val mín),
56,7 Vdc (Val
máx).
Field Resistance @
20ºC 6 up 50Ω.
Static Regulation 0,5%.
Adjustable dynamic
response 8 to 500ms.
Operation
Frequency (jumper
JHz ) 50 or 60Hz.
Sub frequency
protection (U/F) Adjustable via trimpot
Internal percent
adjustment of
voltage Adjustable via trimpot, for the complete range of Voltage VRal
External percent
adjustment of
voltage - 30% of VRal.
Temperature -40° to + 60ºC.
EMI Suppression EMI filter
Approximate Weight 480g
LED Indicators None
Protection for
Excitation Over
current Absentee
Analog Input +/-
9Vdc Optional
Analog Input 0 to
10Vdc Optional
Digital Input Optional
Parallel operation With optional transformer ratio (PAR/1 ratio 1A and PAR/5 ratio 5A

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4.1 NOMENCLATURE FOR REGULATORS
GRT7 - TH4 R2 10A AM/220M E10 D PAR/1
PAR/1: Transformer ratio 1A.
PAR/5: Transformer ratio 5A.
D: Digital input.
E10: Analog input 0 to 10 Vdc.
E9: Analog input +- 9Vdc.
M: Single Phase, T: Three Phase, O: Optional.
Rated supply voltage.
M: Single Phase, T: Three Phase, O: Optional.
Sensing Class
A= 160 to 300V or 320 to 600V.
E= 180 to 240V or 520 to 640V.
G= 85 to 140V or 170 to 280V.
Nominal field current.
Factory defined sequence.
Grameyer Voltage Regulators.

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4.2 PROTECTIONS – U/F OPERATION
Figure 4.2, shows the curves for voltage variation as a function of frequency variation. For nominal frequency operation, U/F is
disabled. When rotation decreases (for ex. when shutting down), excitation diminishes, reducing the output voltage of the
generator. The drop follows a straight line in order to arrive at 0V in 0Hertz. For the case shown on Figura 4.2, the adjustment of
U/F was done on the limit of the nominal frequency.
Figure 4.1 - U/F Curves
This mode of operation is determined by trimpot U/F, jumper JHz and associated components. The JHz jumper determines the
operation frequency, following the following logic:
JHz, position 1 and 2 = 50Hz
position 2 and 3 = 60Hz
The U/F trimpot determines the trigger point of the U/F mode, which can be the nominal frequency (Fn) down to 1/3 of Fn, and
leaves the factory adjusted to 10% below Fn. For operation in 60Hz it is adjusted to 54Hz and for operation in 50 Hz it is
adjusted to 45Hz (see Figure 4.2.2). These values can be altered according to the needs of each application.
Figure 4.2 - Actuation point for U/F protection
ATTENTION
1. Do not set the U/F protection below 20 % of the rated generator frequency. The configuration should be
done according to Figure 4.2.2 to avoid problems when shutting down.
2. The frequency limited by U/F is the frequency of the waveform that is at the power supply input of the
regulator and not at the sensing input (output voltage of the generator).

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4.3 BLOCK DIAGRAM
The structure of the regulator is shown on Figure 4.3.1.
Figure 4.3 - Block diagram of the GRT7-TH4 R2 voltage regulator
The principle of operation is based on the comparison of the RMS sensing voltage with the reference voltage, adjusted by the
sum of the values of Vad trimpot and the external trimpot. The error is processed by the sensing loop and its value determines
the firing angle of the thyristor, which can vary from 0 to 180°, thus controlling the output voltage of the generator. With zero
degree firing, the result is zero volts on the output side of the rectifier, and 180 degrees results in maximum output of the half
wave rectifier.
Generation starts through the generator residual voltage. After the voltage has reached approximately 10% of the nominal
value, the regulator controls the voltage of the generator, taking it through an initial ramp up of approximately 1 second until
reaching nominal voltage. From this point on, the sensing loop will maintain the output voltage of the generator constant within
the adjusted value.
Figure 4 shows the control diagram of the GRT7-TH4 R2 voltage regulator. The control it’s based in ST1A, shown by IEEE ,
and applied to systems where the rectifier is fed from the output of the generator (Type ST – Static Excitation Systems), directly
or through auxiliary coils or through a transformer.
Figure 4.4 - Control diagram GRT7-TH4 R2

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4.4 PARALLEL OPERATION OF TWO OR MORE GENERATORS
The reactive compensation method applied is called phasorial composition (see Figura 4.4.1). On this system, the generator
output voltage is taken and then the composition with the generator current is processed. The result of this interaction
introduces a sensing error in real voltage signal, causing an increase or a decrease in the generator voltage, so maintaining the
reactive between the generators within acceptable values. The adjustment of this compensation is made through trimpot Drp.
According to the diagram shown above, the sensing voltage suffers an influence caused by the current coming from phase S,
which is added to voltage of phases Rand T. The influence in module is small and is large in phase. This means that there is
good compensation for reactive loads and a small influence with active loads. The current transformer for reactive
compensation must be in phase S of the generator, and the voltage feedback must be in phases Rand T.
To make sure the compensation is in the correct sense, proceed as follows:
Operate the generator in stand alone mode (isolated from the system/grid) and apply a resistive load with about 20% of the
generator capacity;
Then rotate the trimpot Drp completely CW. Under this condition, the generator voltage should decrease.
Returning the trimpot completely CCW again, generator voltage should then increase; If this occur, the CT polarity is correct.
Otherwise the CT should be reverted. This procedure is required in each machine, when several machines are connected in
parallel so as to ensure that all CT’s are equally polarized. Some parallel CT characteristics are as follows:
Accuracy Class: 0,6C12,5;
Window or bar type;
Transformer current ratio will be In/5A or In/1A, where In/xA is the Current ratio primary/secondary for example: 100/5A,
150/5A, 100/1A;
Current of the secondary from 5A to regulator PAR/5 and 1A for regulator PAR/1;
The primary current of the CT must be 20% higher than the nominal current of the generator
The working frequency of the CT must be equal to the generator frequency;
The isolation voltage class of the CT must be higher than the output voltage of the generator;
Should withstand 1.2 x In load.
4.5 ANALOG INPUT
The analog inputs of the GRT7-TH4 R2 AVRs have the following characteristics:
Can be –9Vcc to +9Vcc (E9) or 0Vdc to 10Vdc (E10) according to the customer specification.
They are isolated by optocouplers.
Maximum current consumption: 10mA.
Figur
e
4.
5
-
Phasorial Composition of the generator

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5 PROTECTION FUSE
The fuse is used to limit the input current supply in order to extinguish the current in case of failure, avoiding major problems.
The GRT7-TH4 R2 regulator possesses a rectifier that controls the field voltage of the generator. For the maximum field voltage,
the supplied current at input “3” is half of the field current, and the maximum current of the fuse should be a little more than half
of the current supplied by the regulator. Listed below are some of the fuse characteristics:
Recommended manufacturer: LittelFuse
Characteristics: Fast action fuse.
Dimensions: 5x20 mm.
Current/Voltage: 3A/250V for 5A model or 5A/250V for 7A model (Table 4.1).
Time for opening (to blow):
Fuse opening time
% of maximum current
Opening time
110% 4 hours (minimum)
135% Max. 1 hour
200% Max. 1 second
6 STANDARDS
The GRT7-TH4 R2 voltage regulators comply with the following international standards:
Standard Level
Performance
Criterium
IEC 61000-4-5 – Surge immunity test Asymmetrical: 4kV Symmetrical: 4kV B
IEC 61000-4-4 - Electrical fast transient/burst immunity
test 5Khz repetitions, +/- 2kV peak voltage B
IEC 61000-4-3 – Radiated, radio-frequency,
electromagnetic field immunity test
10V/m field for a frequency range from 80MHz to 1GHz. A
10% maximum variation is allowed at the output voltage for a
radiated frequency between 160MHz and 280MHz. For all
other frequencies the equipment doesn’t present variations
A
IEC 61000-4-2 - Electrostatic discharge immunity test Contact: 4kV load;
Through the air: 8kV load. B
IEC 61000-4-11 - Voltage dips, short interruptions and
voltage variations immunity tests Dip f 30db to 95db dips C and B
IEC 61000-4-6 - Immunity to conducted disturbances,
induced by radio-frequency fields 10V amplitude, 150kHz to 80Mhz A

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7 IDENTIFICATION TAG
The above example shows the main characteristics described in the nameplate/ID tag that needs to be checked before installation.
NOTE
1. The ID tag is affixed on the backside of the regulator, and to the Installation Guide.
8 TRIMPOT FUNCTIONS
Vad: Voltage adjustments. Turning clockwise increases voltage;
Stb: Stability adjustments. Turning clockwise slows down stability response
U/F: U/F limiter. Turning clockwise increases the U/F range, counterclockwise it diminishes;
Drp: Droop adjustments. Turning clockwise increases the reactive compensation range;
NOTE
1. A potentiometer for fine adjustments of voltage (5k /3W) can be connected on terminals.
Model Id
Power Input
Field Voltage
Rated Current
Sensing Voltage
Frequency

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9 CONNECTION DIAGRAMS
9.1 GENERATOR CONNECTION WITHOUT AUXILIARY COIL
N
R
S
T
Paral
lelism T ratio In/x¹
Exciter
field
F- F+
Generator
Potentiometer for
external voltage
regulation¹ ² (
5k/3W)
GRT7-TH4 R2
F+
F-
E
E
3
S
S2
P1
P2
S1
S2
E
3/
4
JHz
A- A+
Analog Input
ON/OFF
key³ ³
DW CM UP
Digital Input
Generator Voltage
from 85 to 140 Vca
from 160 to 300 Vca
from 180 to 240 Vca (*)
Faster answer Slower answer
Decrease Increase
Reactives reactives
Frequency Frequenct
Decreases increases
Voltage Voltage
decreases increases

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9.2 GENERATOR CONNECTION WITH AUXILIARY COIL
N
R
S
T
Parallelism CT ratio In/x¹ x¹
Exciter
field
F- F+
Generator
Potentiometer for
external voltage
regulation¹ ² ( 5k/3W) /
GRT7-TH4 R2
F+
F-
E
E
3
Single/parallel switch¹
Open: parallel; Closed:
single
S
S
P1
P2
S1
S2
E
3/
JHz
A
-
A
Analog Input
ON/OFF
key³
DW
CM UP
Digital Input
Generator Voltage
from 170 to 280 Vca
from 320 to 600 Vca
from 520 to 640 Vca
(*)
Generator Voltage
from 85 to 140 Vca
from 160 to 300 Vca
from 180 to 240 Vca (*)
N
R
S
T
Parallelism CT ratio In/x¹
¹
Exciter
field
F- F+
Generator
Potentiometer for
external voltage
regulation¹ ² ( 5k/3W)
GRT7-TH4 R2
F+
F-
E
E
3
S
S
P1
P2
S1
S2
E
3/
4
JHz
A- A+
Analog Input
ON/OFF
key³³
DW CM
UP
Digital Input
Auxiliary
coil