MEWOI MEWOI1200 User manual

H/L Voltage Clamp Meter
MEWOI1200,MEWOI1200C

CONTENT
Warning................................................................................................ 1
Ⅰ. Brief Introduction............................................................................... 3
II. Electrical Symbols............................................................................ 4
III．Series Model.................................................................................. 5
IV．Technical Specification.................................................................. 5
V. Structure........................................................................................... 7
VI．LCD Display .................................................................................. 8
VII．Operation.................................................................................... 10
A. Tester Operation........................................................................... 10
1. Power On/Off.............................................................................. 10
2. General Test ................................................................................11
3. PEAK Test................................................................................... 13
4. Data Maintenance ...................................................................... 14
5. Data Memory.............................................................................. 14
6. Data Reference........................................................................... 14
7. Data Deletion.............................................................................. 14
*8. Data Transmission .................................................................... 14
B .Operation of Receiver.................................................................. 15
1. Power On/Off........................................................................... 15
2. Data Reception........................................................................... 15
3. Data Maintenance ...................................................................... 15
4. Data Memory.............................................................................. 16
5. Data Reference........................................................................... 16
6. Data Deletion.............................................................................. 16

VIII. Replacing Batteries.................................................................. 16
IX. Accessories................................................................................... 17

1
Warning
Thanks for your purchase of MEWOI1200 H/L Voltage Clamp
Current Meter of our company. In order to make better use of this
product, please make sure to:
——Read this manual in detail and the operator must
totally understand this manual and be in proficient in
operation of this meter before making test on spot.
——Strictly comply with the security rules and notice
items listed on this manual.
In any case, it should pay special attention to safety in use of
this meter, particularly in measurement of circuitry with more than
AC100V and above voltages.
If the voltage of tested circuitry has exceeded 600V, it must
be used by connecting with an insulation rod.
As it is very dangerous of high voltage transmission line, the
operator must get strict training and the relevant certification on
high-pressure operation of the state before using this meter and
making a field test.
It is forbidden to use the meter test voltage more than 35 kV
convergence of bare wire or bus
Please pay attention to marked words and symbols on panel
or backboard of this meter.
Please do not put or store this meter in the place of high
temperature, with moisture, with frozen dew or with direct
daylight irradiation for a long time.
Please note the battery polarity when replacing battery, and
remove the battery if you expect not to use this meter for a long
time.
It must be operated by qualified staff that has the
authorization on tearing down or repairing this meter.
Please do not use it when there is any damage on the
transducer clamp or other parts of this meter.

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To avoid the impact of transducer clamp, it needs to maintain
this meter regularly. Do not use corrosive or coarse materials to
clean, but use soft cloth (such as glasses cloth), dipping clean
anti-rust desiccant lubricant (such as WD-40), and making a
gentle wiping.
For the reason of this meter, in case that any danger may
occur if continue to use it, stop using it immediately and seal it
up for keeping at once, which shall be dealt with by qualified
authorization agency.
The danger symbol “ “on the meter and the manual, the
user must make safe operation according to the indication.
The extremely dangerous symbol “ ”, the user must make
safe operation according to the indication.
It suggests that this meter shall be made insulation intensity
test at least once annually. (AC 100kV/rms 5 sections insulating
rod all connections, between both ends)
As to the part with “*”mark in this manual, it is only limited to
MEWOI1200C (wireless Transmission data ).

3
Ⅰ. Brief Introduction
MEWOI1200 Series H/L Voltage Clamp Current Meter has
broken through the traditional structure, which is specially
well-designed for measuring high voltage current, adopt latest CT
technology and integrated mask digital technology, composed of
special clamp current meter and high voltage insulation rods.
Without insulation rods, it can used as high-precision low-voltage
clamp meter and leakage current meter, can accurately measure
the current or leakage current of 0.01mA.
MEWOI1200 Series H/L Voltage Clamp Current Meter adopt
hook type structure of innovation, which can hook the line to test,
save the physical power of user, to ensure the high precision ,
high stability and high reliability of perennial uninterrupted
measurement.
MEWOI1200 Series H/L Voltage Clamp Current Meter
connected with insulation rod, can be used to measure the high
voltage current of the cable under 60KV (with an insulating). or
bare wire cable（≤35kV ）. on-line current measurement, also
having peak maintenance, data preservation, data storage,
wireless transmission and other functions. and its special Clamp
Leaker can make it easier for clamping or evacuating the tested
wire through pressing or pulling back the insulation rod,
time-saving and fast, widely used in transformer substation,
power plant, industrial and mining enterprises as well as the

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inspection station and electrician maintenance departments for
electrical current detection and field electrical operations. It can
also replace the H/L voltage transforming ratio tester, that is, to
detect the high and low current for primary circuit and secondary
circuit separately, and then calculate to conclude the change of
high and low pressure. The insulation rod is light and convenient,
with the advantages of anti-moisture, high temperature resistance,
anti-impact, bending resistance, high insulation, flexibility and
other characteristics.
II. Electrical Symbols
Extremely Dangerous! The operator must strictly abide by
the safety rules. Otherwise, there is electric injury danger,
causing personal damage or casualty accident.
Dangerous! The operator must strictly abide by the safety
rules. Otherwise, there is electric injury danger, causing
personal damage or casualty accident.
Warning! It must strictly abide by the safety rules.
Otherwise, it may cause personal damage or casualty
accident.
Alternating Current (AC)
Direct Current (DC)

5
III．Series Model
Model
Range of
measurement
Accuracy
Jaw
Specification
Description
MEWOI1200
0.00mA-1000
A
0.01mA
Φ68mm
Base
MEWOI1200C
Wireless
IV．Technical Specification
Function
High voltage AC current measurement, low
voltageAC current, leakage current
measurement, on-line AC current supervision.
Power Supply
DC6V Alkaline Dry Battery (1.5V AAA X 4)
Test Method
Clamp CT, Integral Method
*Transmission
Method
MEWOI1200C 433MHz Wireless
Transmission
*transmission
distance
30m
Clamp size
φ68mm
Range of
measurement
0.00mA~1000A(50Hz/60Hz
Auto Identification)
Resolution
0.01mA
Shift
0.00mA~1000A Automatic Shift
Test Accuracy
(23℃±5℃,≤
80%RH)
0.00mA~299mA: ±1%±3dgt
300mA~49.9A: ±1.5%±5dgt
50.0A~199.9A: ±2%±5dgt
200A~600A: ±3%±5dgt
601A~1000A: ±4%±5dgt
Sampling Speed
About 2 times/second
Display Mode
4 digital LCD display
LCD Dimension
Tester LCD：35mm×21.5mm

6
Receiver LCD：47mm×28.5mm
Meter Dimension
Tester: 218mm×135mm×60mm
Receiver: 170mm×75mm×30mm
Data Storage
99 Groups, during storage, the symbol “MEM”
gives indication, “FULL” mark will flash to
indicate the memory has been full.
Peak
Maintenance
Automatically maintain the height of the tes
t value，usually in the test mode press PE
AK key，LCD top right corner will display “PE”，
that is, to keep open the PEAK function, th
en press PEAK key to cancel this function
Circuit Voltage
Test insulating sheath wires（≤60kV ）or bare
wire t（≤35kV ）(operated with insulation rod)
Data
Preservation
Under general test mode, press HOLD button
to preserve data, “DH” symbol display. then
press HOLD Key to cancel (“HOLD”symbol
display)
Data Access
“MR ” symbol indicates, it can read the stored
data by turning upwards and downwards.
Overflow Display
Exceed measurement range overflow function:
“OL A” symbol display
* No signal
Indication
When the receiver has not received transmit
signal, it will display “no- -”symbol
Auto Shut Down
About 15 minutes after booting, the meter will
shut down automatically, in order to decrease
the battery consumption.
Battery Voltage
When the battery voltage is below 4.8V, the
symbol of battery voltage“ ”will show to
remind to replace battery.
Weight
Tester：About 620g (Including battery)

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receiver：About 220g (Including battery)
Total quality of meter: about 2.3kg(including
insulation rod and battery)
Work
Temperature and
Humidity
-10℃~40℃；≤80%Rh
Storage
Temperature and
Humidity
-10℃~ 60℃; ≤70%Rh
Interference
Avoid same frequency interfere(315MHz &
433MHz)
Insulated Rod
Dimension
φ32mm, 1m/ Section（5 Sections）
Insulation
Intension
Tester/receiver:AC 2kV/rms(Between core and
shell)
Insulating rod: AC 100kV/rms (5 sections
insulating rod all connections, between both
ends)
Structure
Anti-Dripping Type II
V. Structure
1. Insulating rod connecting head
2. clamp (boot sector)
3. LCDdisplay
4. PEAK key(start LCD display“PE”)
5. HOLDkey
6. POWER key
7. POWER light
8. Insulating rod (5 sections)

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test test(wireless) receiver
VI．LCD Display
1．Explanation for Special Symbols
⑴.Low battery symbol, when the voltage of battery is
lower than 4.8V, this symbol display, please replace battery
in time.
⑵.“OL A” This symbol indicates that the current on test has
exceeded the maximum measurement limit of the meter.
⑶.“MEM” Memory mode, it will display during the data storage

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process.
⑷.“Full” symbol, when the storage memory has been filled
with 99 groups of data, it will display “FULL” symbol by
flash, which means it cannot continue to store data.
⑸.“MR” data access symbol, which is displayed during looking
up data, meanwhile, it will display the serial number of data
in storage.
⑹.“End” exit symbol, it will display during the exit.
⑺.“dEL” data delete symbol, it will display when deleting data.
*⑻.“no- -”None received signal instructions, dynamic display, it
may not in test mode, or adjust the location and distance
from receiver.
(9). “PE”symbol, press “PEAK”display, Indicates start PEAK
test.
⑽．“HOLD”, “DH”symbol，press “HOLD”display，lock the data.
2．Display Demonstration
⑴. ——The current on test
is 0.002A (2mA)
⑵. ——Locked display Data
——The data is automatic
stored as group 3
——The current on test is: 160.5A
⑶.——The current on test is: 571A
——Low battery symbol
please replace.

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⑷.——Look up data of group 3 in storage
——The current on test is: 160.5A
⑸.—— “FULL” flash display:
Storage is full of 99 groups
——It can’t store more unless
delete storage
⑹.——“dEL” Indication of data delete
⑺.—— “End” Indication of exit
*⑻.——“no- -”Dynamic display: none
received signal
VII．Operation
Please check all parts of the meter carefully before
usage, to see whether there is any damage. And
make sure no damage before usage.
According to manual instructions to install the
battery
A. Tester Operation
1. Power On/Off
Press POWER button to power on, the instrument will displays the
LCD screen, entering normal testing mode. If LCD display is
relatively dark after power on, it is possible that battery voltage is a
bit lower. Please replace battery. 15 minutes after powering on the
meter, if it remains idle, an auto-power off procedure starts to
preserve the battery life and LCD will continue flash until the
complete switch off takes place after 30 seconds. In case of LCD

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continuous flash, press POWER button, then the meter will
continue to work.
Under HOLD mode, press POWER button for power off.
Under general test mode, press POWER button to power off.
Under PEAK testing mode，press POWE button to power off.
Under data reference mode, firstly press POWER button for more
than 3 seconds to exit from data reference mode, returning to
normal test mode, then press POWER button to power off. During
the exit from data access, it will display “End” symbol.
2. General Test
High voltage, extremely dangerous! It must be operated
by qualified staff that has acquired authority. The operator
must strictly abide by the safety rules. Otherwise, there is
electric injury danger, causing personal damage or
casualty accident.
Dangerous! It is forbidden to use the meter test
voltage more than 35 kV convergence of bare wire or
bus.Otherwise, there is electric injury danger, causing
personal damage or equipment damage.
Dangerous! It cannot be used to measure the circuit over
600A voltage. Otherwise, there is electric injury danger,
causing personal damage or equipment damage.
General Test: In the process of test, LCD will display the tested
current value real time, and LCD data will vary with the current
change. When the tester is removed away from the lead on test, it
does not preserve the test result, LCD display will return to zero.
In normal testing mode, it is suitable for close distance
measurement, convenient for circuit test by direct read of LCD
data.

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Before test, firstly to connect insulation rod, which
must be connected in right position, and then to
connect tester, avoiding the impact of meter to ground
surface.
Make sure to use specially equipped insulation rod to
connect with the meter.
After test, it should incline the insulation rod
accordingly on drawing in. Firstly to tear down the
tester and then the insulation rod, avoiding the impact
of meter to ground surface.
After normal boot, place the lead in the middle of clamp transducer
domain,The drop-down instrument clamped conductor to be
tested，showing the result on LCD display. If showing "OL A", it
means the lead current on test has exceeded the maximum
volume on the level. Please select a higher gear level or a meter
with greater measurement limit. Push the instrument can be
evacuated before conductor to be tested

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Under HOLD mode, press HOLD button to cancel HOLD function,
and return to normal testing mode.
Under data reference mode, press POWER button for more than 3
seconds to exit from data reference mode, returning to normal
testing mode.
Under PEAK testing mode, press POWER button to exit from
PEAK testing mode, returning to normal testing mode.
After data deletion, it will return to normal testing mode
automatically.
Attention! For the sake of safety, when test has been
finished, please remove the meter away from the
lead on test
3. PEAK Test
PEAK test: the maximum current test. the meter will make
automatic comparison on the changes in measured current,
indicating the maximum value and maintain it, when the meter is
removed away from the lead on test, the test result will be kept
consistently, suitable for the circuit test on those LCD data hard to

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be read directly
Under the normal testing mode, press PEAK button, LCD display
“PE”, enter PEAK testing mode. That means the meter will display
and automatically keep the maximum value in the test.
Under any other mode, it must be returned to normal testing mode,
and then make PEAK testing according to the above operation.
Press POWER button to exit from PEAK testing mode, returning to
normal testing mode.
4. Data Maintenance
Under normal testing mode, press HOLD button to keep LCD
display. Press HOLD button again to release data lock, returning to
normal testing mode.
5. Data Memory
Under normal testing mode, press HOLD to storage data, at the
same time, Meter will automatically form serial numbers, and
memory the current preserved data. This meter can memory 99
groups of data, in case of full storage, “FULL” symbol will display
by flash continuously, and it cannot continue to memory until
cleaning out the previous memory.
6. Data Reference
Under normal testing mode, press PEAK + POWER button to
enter data reference mode, meanwhile, it will automatically display
data saved in the group 01. Then press PEAK or POWER button
to read the stored data by turning upwards or downwards in cycle.
It will return to the group 1’s data automatically after reaching the
last group’s data in storage.
Press HOLD button to exit from data reference mode, returning to
normal testing mode. During the exit, it will display “End” symbol.
7. Data Deletion
Under data reference mode, press PEAK + POWER button to
delete all the data in storage, and return to normal testing mode.
During the deletion of data, it will display “dEL” symbol.
*8. Data Transmission
MEWOI1200C: has the function of wireless data transmission.
When the Meter under testing mode, the test result will be

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transferred to receiver by wireless transmission and the receiver
will display test result real time, being clear at a glance.
Only under testing mode, the meter will transmit, If the receiver has
not received emission signals, it will display “no - -” symbol
dynamically.
B Type: Transferred
MEWOI1200C: Wireless transmission test data, a straight-line
distance of about 30 meters, can penetrate the floor to receive
data.
B .Operation of Receiver
(Note: For MEWOI1200C only)
1. Power On/Off
Press POWER button to power on, the instrument will displays the
LCD screen, entering normal testing mode. If LCD display is
relatively dark after power on, it is possible that battery voltage is a
bit lower. Please replace battery. 15 minutes after powering on the
meter, if it remains idle, an auto-power off procedure starts to
preserve the battery life and LCD will continue flash until the
complete switch off takes place after 30 seconds. In case of LCD
continuous flash, press POWER button, then the meter will
continue to work.
Under HOLD mode, press POWER to power off.
Under data reference, first, press POWER button( for 3 seconds )
to exit data reference mode, then come back to data receive mode,
press POWER button once again to power off. During exit from
data reference, it will display the symbol of “End”.
2. Data Reception
After normal power on, the receiver will under receiving mode. If
there are emission data, the receiver will display the test result real
time. If it has not received any signal, the receiver will search
signals constantly, and display “no- -”symbol dynamically.
3. Data Maintenance
Under Data Reception mod, press HOLD button, keep LCD
display, “HOLD” symbol indication. Press HOLD button once

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again to relieve data lock, return to data reception mode, “HOLD”
symbol display.
4. Data Memory
Under Date Reception mode, press HOLD button to maintain data,
meanwhile, the receiver will automatically form serial numbers,
and memory the current preserved data. During the storage,
“MEM”symbol will display once by flash. The receiver can memory
99 groups of data, in case of full storage, “FULL” symbol will
display by flash continuously, and it cannot continue to memory
until cleaning out the previous memory.
5. Data Reference
Under Data Reception mode, press HOLD+POWER button to
enter Data Reference mode, “MR” symbol display, meanwhile, it
will automatically display data saved in the group 1. Then press
HOLD button or POWER button to read the stored data by turning
upwards or downwards in cycle. It will return to the group 1’s data
automatically after reaching the last group’s data in storage.
Press POWER button for more than 3 seconds to exit from data
reference mode, returning to receiving data mode. During the exit,
it will show “End” symbol.
6. Data Deletion
Under data reference mode, press HOLD + POWER button to
delete all the data in storage, and return to Data Reception mode.
During the deletion of data, it will display “dEL” symbol.
VIII. Replacing Batteries
Warning! In case that the battery’s cover board is not
well closed, it is forbidden to make test. Otherwise, it is
dangerous.
Pay attention to the polarity of battery, in case of
damage to the meter.
Do not mix in the use of new and old batteries.
1. When the battery voltage is below 4.8V, the meter will display