Huazheng HZ-3100A User manual

HZ-3100A
Transformer DC resistance Tester
User Manual
Huazheng Electric Manufacturing (Baoding) Co., Ltd

Dear use r:
Thank you for cho os in g HZ-3 10 0A Transfor mer DC resistance Tester.
We hop e that thi s in st rument can make your work eas ier and mo re
enjo yabl e, so that yo u can get the feeling of office aut om at ion in the test
and an al ysis work.
Be fore us ing the instrument, pl ea se read this man ua l, and operate an d
maintain the instrum ent accordi ng to the manual to pr olong its service life.
"Just a light press, the test will be compl eted automati cally" is th e
oper at ing cha racteristics of this instrument.
If you ar e sat isfied with this instrum ent, please tell your co lleagues;
if you are no t satis fied with thi s in st ru ment, please ca ll [phone] to
te ll you to ser ve you at al l tim es -Bao di ng Hu az he ng Elect ri c Manufacturing
Co. , Lt d., our company will de finite ly make you satisfied !

Contents
I.Overview.......................................................................................................................................... 1
II.Main Technical index....................................................................................................................2
III.Main functions and features....................................................................................................... 3
IV. Panel structure............................................................................................................................ 3
V. system introduction..................................................................................................................... 4
VI.Method of operation.................................................................................................................... 5
VII.Matters needing attention........................................................................................................10
VIII. Packing List............................................................................................................................. 11

1
I.Overview
Transformer DC resistance is a must-test item in transformer manufacturing for
semi-finished products, finished products, factory test, installation, overhaul, after tap
changer change, handover test, and preventive test in the power sector. You can check
the welding quality of the winding joints and whether the windings have inter-turn short
circuits. You can check whether the contact of each position of the voltage tap changer is
good, whether the actual position of the tap changer matches the indicated position,
whether the lead wire is broken, and multiple strands of wire are wound Whether there is
any stock breakage, etc. In order to meet the needs of rapid measurement of transformer
DC resistance, the HZ-3100A DC resistance tester developed by our company. The
instrument adopts a brand-new power supply technology, which has the characteristics of
small size, light weight, large output current, good repeatability, strong anti-interference
ability, and complete protection functions. The whole machine is controlled by a
high-speed single-chip microcomputer, with a high degree of automation, with automatic
discharge and discharge alarm functions. The instrument has high test accuracy and
simple operation, which can realize the rapid measurement of transformer direct
resistance.

2
II.Main Technical index
Item
Technical indicators and parameters
Note
Test current
5A、10A、20A 、50A、100A
Measuring range
50μΩ～100mΩ （100A）
100μΩ～400mΩ （50A）
200μΩ～1Ω （20A）
500μΩ～2Ω （10A）
1mΩ～4Ω （5A）
Min resolution
0.1μΩ
Accuracy
±(0.2%+2 reading)
Display
LCD Monitor
Resistance display effective
digits are 4 digits
Data storage
1000 sets
Working
environment
Ambient temperature:0℃～40℃
Relative humidity: <90%RH
No condensation
Power supply
AC 220V±10V，50Hz±1 Hz
Insurance tube 10A
Max power
consumption
1000W
Overall
dimensions
440×245×395（mm）
Weight
Instrument: 19.8Kg Wire box:
7.5Kg

3
III.Main functions and features
1. The whole machine is controlled by high-speed single-chip microcomputer, with high
degree of automation and easy operation.
2. The instrument adopts brand-new power supply technology, with multiple current gears
and wide measurement range, suitable for DC resistance measurement of large and
medium-sized transformers.
3. The protection function is perfect, which can reliably protect the impact of the back
EMF to the instrument, and the performance is more reliable.
4. With sound discharge alarm, discharge indication is clear, reduce misoperation.
5. Fast response speed.
6. Intelligent power management technology, the instrument always works in the
minimum power state, which effectively saves energy and reduces heat generation.
7. 320X240 dot matrix ultra-small pixels 65K true color LCD,
8. The instrument comes with a perpetual calendar clock and power-down storage, which
can store 1000 sets of test data, which can be consulted at any time
9. The instrument is equipped with RS232 and USB interfaces, which can communicate
with computers and store in U disk
10.Comes with a panel-type micro printer, which can print the measurement results in
Chinese
IV. Panel structure

4
AC220 switch: the working power of the instrument, AC 220V.
Grounding post: grounding point of the whole instrument for safety protection
Reset button: press this button, the machine is in the initial state, and the output current
can be preset.
Cycle key: press this key to scroll the cursor in the main menu
Selection key: After the unit is reset, press this key to perform current preset.
Start key: Press this key after the output current is selected, and the microcomputer
control realizes the whole test process.
I+, I-: output current binding posts, I+ is the output current is positive, I- is the output
current is negative.
V+, V-: Voltage sampling terminal, V+ is the positive terminal of the voltage line, and V- is
the negative terminal of the voltage line.
RS232: Universal serial interface, the instrument can be controlled by a computer.
USB: can output test results to U disk.
V. system introduction
The panel of the instrument is shown below
AC220 switch: the working power of the instrument, AC 220V.
Grounding post: grounding point of the whole instrument for safety protection
Reset button: press this button, the machine is in the initial state, and the output current

5
can be preset.
Cycle key: press this key to scroll the cursor in the main menu
Selection key: After the unit is reset, press this key to perform current preset.
Start key: Press this key after the output current is selected, and the microcomputer
control realizes the whole test process.
I+, I-: output current binding posts, I+ is the output current is positive, I- is the output
current is negative.
V+, V-: Voltage sampling terminal, V+ is the positive terminal of the voltage line, and V- is
the negative terminal of the voltage line.
RS232: Universal serial interface, the instrument can be controlled by a computer.
USB: can output test results to U disk.
VI.Method of operation
1. The boot interface is shown in Figure 1:
Figure 1
Figure 2
Press the cycle key and the cursor can move among the options included in current
selection, phase tapping, winding temperature, conversion temperature, data query, host

6
parameters, clock modification, etc., press the selection key to cycle through the options
included in the above seven main menus select.
(1) When the cursor is in the current selection, press the selection key to select the current.
(2) When the cursor is on the phase tap, when the cursor is on the phase tap, press the
select key, and the phase can be selected from AB, BC, CA, AO, BO, CO, ab, bc, ca, ao,
bo, co Cycle display between. Press the start key to move the cursor to tap, press the
select key to change the number between 0-9 (ten's place), press the start key to move
the cursor to the ones place, press the select key to change the number between 0-9.
(3) When the cursor is at the winding temperature, press the start key to scroll the cursor
among the three data bits, and the select key can make the data of each data bit cyclically
display between 0-9.
(4) When the cursor is at the conversion temperature, press the select key, and the
conversion temperature can be displayed cyclically among 75℃, 85℃, 115℃, 125℃and
145℃.
(5) When the current option is any option except winding temperature, press the start key
to start the measurement.
2. After the current is selected, press the start button to start charging. After the LCD
displays "Charging" for a few seconds, it displays "Testing" at this time, indicating that the
charging is completed and the test state is entered. After a few seconds, the test result will
be displayed, as shown in Figure 3:
Figure 3
According to the prompt, press the select key for about two seconds to print the current
data, and press the cycle key for about two seconds to store the current data to the U disk.
3. Move the cursor to the data query menu in the boot interface, and then press the select

7
key to enter the data query, as shown in Figure 4:
Figure 4
In Figure 4, when the cursor is in the data query, press the select key to scroll up the data,
and press the start key to scroll down the data. Move the cursor to print, press the select
key to print the current display data according to the prompts, move the cursor to the U
disk for storage, and press the select key to store the current display data to the U disk
according to the prompts.
4. In Figure 2, press the cycle key to move the cursor to the clock modification, press the
select key to enter the clock modification interface,
Figure 5
Press the cycle key to move the cursor between each date data, press the select key to
decrease the data, and press the start key to increase the data.
5. Move the cursor to the host parameter in Figure 2 and press the select key to enter the
interface as shown in Figure 6:

8
Figure 6
Press the cycle key to move the cursor. When the cursor increases on the screen
brightness, press the select key to increase the screen brightness. When the cursor is on
the screen brightness reduction, press the select key to decrease the screen brightness.
When the cursor is releasing the storage space, press the select key to clear the storage
data.
6.Test and operation method
A: Single-phase measurement method, see Figure 7 below:
Figure 7
B. The wiring of the assisted magnetic method is shown in Figure 8~10 (applicable to
Y(N)-d-11 connection group).When measuring the low-voltage side of a large-capacity
transformer, if the maximum current of the DC resistance tester is relatively small under
existing conditions, or in order to speed up the measurement, you can choose the
magnetic method to measure. In the figure below, Figure 8, Figure 9, and Figure 10 are

9
the wiring methods for measuring low voltage Rac, Rba, and Rbc respectively
Figures 8, 9, and 10 are the wiring methods for measuring low voltage Rac, Rba, and Rbc
respectively

10
VII.Matters needing attention
1. After measuring the inductive load, the test line cannot be directly removed, so as not to
endanger the safety of testers and equipment due to inductive discharge. The output
terminal of this machine is equipped with a discharge circuit. After the instrument is reset,
the inductance will discharge energy through the instrument. The test wire must be
removed after the discharge instruction is completed.
2. For no-load tap-changing transformers, it is not allowed to switch the tap switch during
the measurement process.
3. If the power supply is suddenly cut off during the measurement process, the machine
will automatically start to discharge. Please do not disassemble the wiring immediately.
Wait at least 30 seconds before disassembling the wiring.
4. During measurement, do not short-circuit the grounding of other untested windings,
otherwise it will slow down the magnetization process of the transformer, prolong the data
stabilization time or the value is incorrect.
5. Please check the power supply voltage before starting up: AC 220V±10%, 50Hz.
6. During the test, please confirm that the device under test has been powered off and
disconnected from other live devices.
7. The case must be grounded reliably during the test.
8. Irrelevant items are not allowed to be stacked on and around the equipment panel
during the test.
9. When replacing the fuse and accessories, please use the same model as this
instrument (see technical specifications for details)
10. Pay attention to moisture and oil pollution for this instrument.
11. When selecting the current, please refer to the range in the technical index column.
When the range is exceeded, the instrument is always in the "charging" state because the
current does not reach the preset value. At this time, press the reset button to reset the
instrument and select a smaller value. The current gear.

11
VIII. Packing List
No.
Name
Qty
1
main engine
1
2
Test line
1
3
Power line
1
4
Power line
2
5
Print paper
1
6
Ground lead
1
7
Data line
1
8
Test product
1