HVTest SGB-C Series User manual

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Dear Client
Thank you for Purchasing our SGB-C Digital Voltage Divider.
Please read the manual in detail prior to first use, which will help
you use the equipment skillfully.
Our aim is to improve and perfect the
company's products continually, so there may be
slight differences between your purchase equipment
and its instruction manual. You can find the changes
in the appendix. Sorry for the inconvenience. If you have further
questions, welcome to contact with our service department.
The input/output terminals and the test column
may bring voltage, when you plug/draw the test wire or
power outlet, they will cause electric spark. PLEASE
CAUTION RISK OF ELECTRICAL SHOCK!
Company Address:
T4，No. 41, High-tech 2 Road，East Lake High-tech Development Zone，
Wuhan
Sales Hotline: [phone]
After Service Hotline:[phone]
Fax: [phone]
E-mail: [email protected]
Website: www.hvtest.cc

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SERIOUS COMMITMENT
All products of our company carry one year limited warranty
from the date of shipment. If any such product proves defective
during this warranty period we will maintain it for free. Meanwhile
we implement lifetime service. Except otherwise agreed by
contract.
SAFETY REQUIREMENTS
Please read the following safety precautions carefully to avoid
body injury and prevent the product or other relevant subassembly
to damage. In order to avoid possible danger, this product can only
be used within the prescribed scope.
Only qualified technician can carry out maintenance or repair
work.
--To avoid fire and personal injury:
Use Proper Power Cord
Only use the power wire supplied by the product or meet the
specification of this produce.
Connect and Disconnect Correctly
When the test wire is connected to the live terminal, please do
not connect or disconnect the test wire.
Grounding
The product is grounded through the power wire; besides, the
ground pole of the shell must be grounded. To prevent electric

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shock, the grounding conductor must be connected to the ground.
Make sure the product has been grounded correctly before
connecting with the input/output port.
Pay Attention to the Ratings of All Terminals
To prevent the fire hazard or electric shock, please be care of
all ratings and labels/marks of this product. Before connecting,
please read the instruction manual to acquire information about the
ratings.
Do Not Operate without Covers
Do not operate this product when covers or panels removed.
Use Proper Fuse
Only use the fuse with type and rating specified for the product.
Avoid Touching Bare Circuit and Charged Metal
Do not touch the bare connection points and parts of energized
equipment.
Do Not Operate with Suspicious Failures
If you encounter operating failure, do not continue. Please
contact with our maintenance staff.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in Explosive Atmospheres.
Ensure Product Surfaces Clean and Dry.

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－Security Terms
Warning: indicates that death or severe personal injury may
result if proper precautions are not taken
Caution: indicates that property damage may result if proper
precautions are not taken.

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Contents
I. Product introduction.............................................................................. 6
II. Features................................................................................................. 6
III. Technique parameters....................................................................... 7
IV. Measuring principle............................................................................ 8
V. Panel layout.......................................................................................... 9
VI. Measurement preparation............................................................... 10
VII. Operation instruction.......................................................................10
VIII. Change battery................................................................................12
IX. Notes...................................................................................................12
X. Problems and Solutions....................................................................13

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I. Product introduction
This product is an idea device for HV measuring; mostly apply in power
system, electronic equipment factory to test frequency AC high voltage and DC
high voltage.
This product is composed by HV divider and LV display meter. The two
parts are connected by the supporting cable.
II. Features
1. High precision
Uses high precision HV thin-film capacitor and HV glass glaze resistor,
input impedance is high, lower the measured current, small power
consumption, improves the accuracy and stability of the device.
For signal processing, adopts high performance OP to amplify the signal,
uses the newest dual integrating A/D sampling technique, four and half LCD
display, the maximum resolution up to 0.001kV, it is the replacement products
for HV electrostatic voltmeter.
2. Good anti-jamming performance.
Adopts special shield technique. equipotential ball uses aluminum , effectively
improves the electric field distribution around the equipotential ball, prevents the point discharge,
improves the anti-jamming ability of the test results. LV display meter is full metal enclosed
instruction to shield, Coaxial cable connect the HV divider and LV display meter,
reduce the effects to indicating value by high voltage, then realize high stability,
high linearity.
3. Safe and reliable.
This device is composed by HV divider and LV display meter, the HV
divider uses America Dupont packing material, special technique to embed,
with smaller structure, lighter weight, lower the internal partial discharge to the
least, more reliable, do not leak oil. Coaxial cable connect the HV divider and
LV display meter when working, the HV and LV parts are far away from each

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other, safe and reliable.
4. Easy to operate.
Uses toggle switch to shift HV/LV, AC/DC, convenient and swift. Four and
half LCD directly display the test results, easy and clear. Bring great
convenience for field tests.
5. Convenient to carry.
Portable structure, the whole machine use aluminum alloy package as
case, can easily to disassemble. Small in volume, light in weight, convenient to
carry and use.
III. Technique parameters
1. Partial pressure ratio of voltage divider: 1000:1
2. Insulating medium: dupont dry dielectric
3. Ac measurement: true effective value measurement
4. Environmental conditions:
Temperature: 0 ~ 40℃
Wet degree: 85% RH or less
5. Specification parameters:
型号
电压等级
精度
量程
阻抗
（MΩ）
信号线
长度
外形尺寸
（mm3）
质量（kg）
SGB-50C
AC：
50kV,DC：
50kV
AC：
1.0%
DC：
0.5%
Low：
0-20kV,High：
0-50kV
600
3m
180*180*620
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SGB-100C
AC：
100kV,DC：
100kV
AC：
1.0%
DC：
0.5%
Low：
0-20kV,High：
0-100kV
1200
3m
180*180*900
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SGB-150C
AC：
150kV,DC：
150kV
AC：
1.0%
DC：
0.5%
Low：
0-20kV,High：
0-150kV
1800
4m
250*250*1100
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SGB-200C
AC：
200kV,DC：
200kV
AC：
1.0%
DC：
0.5%
Low：
0-20kV,High：
0-200kV
2400
4m
250*250*1330
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SGB-300C
AC：
300kV,DC：
300kV
AC：
1.5%
DC：
1.0%
Low：
0-20kV,High：
0-300kV
3600
5m
250*250*1900
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IV. Measuring principle
Figure 1 measuring principle
This device uses resistance-capacitance voltage division method to test
HV AC & DC, which as shown in figure 1. The left side is high voltage part,
uses resistance-capacitance division circuit, which composed by impedance
Z1 and Z2. High voltage Ui input from the upper equipotential ball, low voltage
sampling signal output from Z2; the right side is the LV display meter, which
used for processing the Uo. Uo is processed by rectifying filter amplifier and
displayed by LV display instrument. The relationship between Ui and Uo as
shown in formula (1)

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2
21
Z
ZZ
Ui
Uo


（1）
V. Panel layout
This product is composed by high voltage divider and low voltage display
meter.
1. High voltage divider
Figure 2 high voltage divider
①equipotential ball
②insulating cylinder of divider
③ground pole
④signal sampling
output
⑤base of divider

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2. Low voltage display meter
Figure 3 Low voltage display meter
①LCD
②signal sampling input
③Power switch
④DC/AC selection
⑤High/low gear switching
VI. Measurement preparation
1. This device is HV equipment, please make test in open field.
2. Service conditions:
Temperature :0~40℃, humidity≤85%RH.
3. Power on the LV display meter to check if the LCD display clearly, if not
clear or nothing display, please check the battery inside of the display meter.
VII. Operation instruction
1. Correct connection
Correctly connect as Figure 4 shown. High-voltage input connect to the
terminal at the top of equipotential ball, using earth lead connect ground
terminal to earth, HV divider and LV display meter should be connected with the
supporting coaxial cable. Completed connection, please check the connections
and confirm all is correct, then select the appropriate gear and range, you can

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start measuring.
Note: This instrument has auxiliary earth wire, and there are special earth
terminal at the base of high voltage divider, so before each use, earth terminal
must be firmly grounded. High-voltage test line must be use high voltage lead
and the test line must be elevated, cannot too close to ground. Keep HV divider
and LV display meter at least more than two meters distance. During test,
testers should keep more than two meters safe distance near high-voltage
divider.
Fig. 4 wiring diagram
①High-voltage input
②earth lead
③signal line（original supporting cable）
2. Power frequency HV measurement
After correct connection, press "power switch” of LV display meter, switch
the function switch to AC gear, select “high” gear, power frequency HV can be
measured, LCD display value is the measured power frequency HV value. If
measuring voltage is lower than 20kV, you can switch function switch to “low”
gear in order to obtain higher accuracy. After test, cut off high voltage, LV
display meter returns to zero, then you can enter the site. (Under AC test, the

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meter will slowly return to zero, but the high-voltage power supply may have no
electricity.)
3. DC high voltage measurement
After correct connection, press "power switch” of LV display meter, switch
the function switch to DC gear, select “high” gear, DC high voltage can be
measured, LCD display value is the measured DC high voltage value. If
measuring voltage is lower than 20kV, you can switch function switch to “low”
gear in order to obtain higher accuracy. After test, cut off high voltage, LV
display meter returns to zero, then you can enter the site. Note: When
measuring DC, because there are filter capacitor, you must firstly discharge
after completed measurement, then you can near the HV divider.
4. Use High-voltage divider singly
High-voltage divider can be used alone with the common multimeter
instead of LV display meter. The divider ratio of High-voltage divider is 1000:1;
the display value of multimeter multiplied by 1000 is equivalent to the measured
high voltage value. Changing the unit of the display value in multimeter to kV is
ok.
VIII. Change battery
Open the LV display meter, if you find vague LCD display or no response,
indicating that the instrument internal battery voltage is low, it needs to be
replaced. Specific steps are as follows:
1. Press “power switch” to turn off power supply of LV display meter.
2. Unscrewing four screws on the LV display panel, and remove the panel.
3. Unscrewing the screw on the battery box and open the battery cover,
then replace the 9V battery. (Note the positive and negative polarity of battery)
IX. Notes
1. When using this device, please make sure on sundries draw round it, so

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as not to affect measurement accuracy.
2. Please keep a safe operation distance to ensure operational safety.
3. Check whether all parts are firmly connected, especially ground
connection must be solid.
4. After completing the measurement, until the meter returns to zero, it is
allowable to enter the site.
5. Completed DC high voltage measurement, the instrument must
discharge.
6. Overvoltage use is strictly forbidden. Please keep the surface clean.
7. Handle with care, do not crash and extrude.
8. Do not use the equipment; it should be cased and placed in a cool dry
place.
9. Calibration: At least once a year at a superior metrology calibration
department, or return to factory calibration.
X. Problems and Solutions
Problem
Solution
After starting up, no respond and
LCD no display.
Replace the battery
Test results are too much
deviation.
Check whether the coaxial cable is well
connected.
There is more obvious discharge
sound when measuring.
Check whether the ground is good.
HV divider may be damp, PLEASE wipe
the shell with a dry cloth and then blow it
for five minutes with blower.