MEWOI 7800 User manual

MEWOI 7800
HIGH ACCURACY CLAMP LEAKER
USER MANUAL
www.mewoi.com

CONTENT
Warning...................................................................................................1
I Introduction...........................................................................................3
II Electrical Signs....................................................................................4
III Technical Specifications....................................................................5
IV Structure of the Leaker.....................................................................7
V Operating Method ..............................................................................8
1.Start-up, Shutdown........................................................................8
2.Leaker Measurement .....................................................................8
3. Peak Holding ..............................................................................11
4. Hold, Storage andAccess Reading.............................................11
VI Function Quick Look Up.................................................................12
VII Display Example and Meaning....................................................13
VIII How to Change Battery................................................................14
IX Accessories......................................................................................15

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Warning
Thank you for purchasing our company's High Accuracy Clamp
Leaker, for better use of this product, please:
——Read carefully the user's manual.
——Follow strictly safety rules and notes listed in this manual.
Under any circumstances, please pay special attention to your safety in
the course of using this leaker.
Give heed to label texts and symbols on panel and back plate of this
leaker.
Please don't place and store this leaker in hot and humid condition,
locations with moisture condensation and under direct sunlight for a long
time.
In case voltage of battery was low , please replace batteries.
If you expect not to use the leaker for a long time, please take out
batteries.
When changing batteries, please pay attention to the polarity of battery.
Use, disassembly and maintenance of this leaker shall be operated by
authorized personnel.

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In case dangers would occur if continue to use a faulty leaker, please stop
to use it and seal it for safekeeping immediately; and then, send it for
disposal of authorized agency.
Users shall carry out operation based on danger signs “ ” on leaker
and manual.
Users shall carry out safety operation based on instructions listed in this
manual, e.g. “ ” and danger signs on this manual.
Please use mA to test leakage current (test by clamping grounding line,
single-phase line together).

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I Introduction
MEWOI7800 High Accuracy Clamp Leaker is specially designed for
measurement of AC leakage current; by adopting up-to-date CT technology
and digital integration technology, it is a product with relatively small size,
large clamp, high accuracy and perfect function compared with similar
leakers in the world. The leaker could be widely applied in those fields as
electricity, communications, meteorology, railroad, oilfield, construction,
measurement, scientific & research teaching institutes, industrial and mining
establishments. Clamp core of this High Accuracy Clamp Leaker adopts
special alloy; in addition, with utilization of magnetic shielding technology, it
is almost free from influences of external magnetic field so as to ensure high
precision, high stability and high reliability of perennial continuous
measurement.
This High Accuracy Clamp Leaker obtains one USB interface. With the
help of the software that we provide, many functions are available. For
example, on-line monitoring, historical data inquiry，active curve drawing,

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indication of max, min and average value and indication. There are also
functions like saving to documents and printing when connected to PC. It is
an essential tool for electrician safety testing.
II Electrical Signs
Extremely dangerous! Operators shall strictly keep to
safety rules; otherwise there would be dangers of electric
shock to cause personal injuries or casualties.
Dangerous！Operators shall strictly keep to safety rules;
otherwise there would be dangers of electric shock to
cause personal injuries or casualties.
Warning！Operators shall strictly keep to safety rules;
otherwise personal injuries or equipment damages might
be caused.
Double insulation
AC
DC

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III Technical Specifications
Function
Measurement of AC leakage current, AC
current and on-line measurement
Power
Zn-Mn dry battery,6F22,9V
Size of jaw
Φ68mm
Test Mode
Clip-on CT，integral mode
Display Mode
Four digits LCD display
Dimension
Width ×Height×Thickness：
175mm×70mm×38mm
LCD Dimension
35mm×21.5mm；display domain：32mm×15mm
Sampling Rate
about 2 times/s
Frequency
50/60Hz Automatically
Range Shift
Automatically
Accuracy
（23℃±3℃,
below 70%RH）
0.00~59.9A: ±1.5%±5dgt
60.00A~199.9A: ±2%±5dgt
200.0A~599A: ±3%±5dgt
600A~1200A: ±4%±5dgt
Voltage Range
AC600V
USB Interface
Data stored in the memory of the meter via
USB upload to PC, or on-line monitoring

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USB line
1.5m
Storage
99units，all used when display FULL
Peak Hold
Push HOLD without release, the meter will
show the peak value during the pushing period
Reading Hold
DH indicating the reading is hold
Out of Range
OL indicating the current is out of range
Auto Power-off
5 Minutes after power on, it will power off
automatically to lower the power consumption
Battery Voltage
Indicating the battery voltage is lower then
7.2V.Then the battery have to be changed
Weight
120g（including the battery）
Consumption
About 15mW
Temperature
and Humidity
Working: 0℃~ 40℃,below 80%rh
Storage: -10℃~60℃,below 70%rh
Insulating
Strength
AC2kV/rms (between the alloy of the clamp
and the housing)
Applicable
Safety Rules
IEC1010-1、IEC1010-2-032、pollution, etc 2、

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CAT Ⅲ(600V)
IV Structure of the Leaker
1. Double Input Totpid
2. Upper Cover
3. Totoid Opening Lever
4. HOLD Key
5. POWER key
6. LCD
7. USB Interface
8. Back cover
9. Screw of up/down cover
10. Battery cover
11. Screw of battery cover

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V Operating Method
1. Start-up, Shutdown
Press POWER key to start up, LCD will begin to display; Press the
POWER key again, the leaker will shut down. After starting up for 5
minutes, LCD will flick notes that the leaker will shut down
automatically; after flickering for 30s, it will shut down formally to
reduce battery consumption. In case you have pressed POWER key
when LCD was flickering, the leaker will continue to work for 5 minutes.
If LCD was very dark after starting up, it might be caused by
low-voltage battery, in this case, please change battery immediately.
2. Leaker Measurement
High voltage, extremely dangerous! Operators shall
strictly observe safety rules; otherwise there would be
risk of electric shock to cause personal injuries or
casualties.
Dangerous！Please don’t use it to measure current
higher than 300A; otherwise there would be risk of
electric shock to cause personal injuries or equipment
damages.
1）Power on.
2）Press down trigger to open clamp head and clamp to-be-measured

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Conductors (Be attention that clamp heads must be totally closed)
Clamp live wire and null line together is to measure
leakage current of electrical equipment. (Note: 2
lines)
Clamp earth wire is to measure grounding line
leakage current of electrical equipment.
(Note: single line)
Clamp main line is to measure total current of that
main line.（Note: single line）
Clamp 3 phase 3 wire together is measure the
leakage current of 3 phase 3 wire(Note: three line)
Clamp 3 phase 4 wire together is measure is
measure the leakage current of 3 phase 4 wire(Note:
four line)

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Attention! For your safety, when measuring heavy
current, after confirmed the completion of correct
operating test, please move the leaker away from
measured conductor.

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3）Read LCD display data. In case OL mA symbol was displayed, it
means that current of measured line is beyond the maximum limit of
this leaker; with this case, please shift gear with much higher range
limit.
In locations with difficulty to read out data, please
use the data holding function. If [DH] symbol
displayed, please discharge data holding state
first, and then do the test.
3. Peak Holding
Pressing HOLD key continually in the course of measurement (More
than 3 seconds), the leaker will capture current peak values of lines in
this period of time; release the key, it then will return to measuring state
4. Hold, Storage and Access Reading
1）Pressing HOLD key for a short time in the course of measurement
(less than 3 seconds), DH symbol will display, the leaker will hold current
measuring data and automatically stored in the memory with a unit ID;
press HOLD key again to release the hold state, and the leaker continues
its measuring; in case stored data reached to 99groups, press HOLD key
again, the “FULL” symbol will display, which means storage memory is
full; press HOLD key to cancel “FULL” flickering and return to
measuring mode.
2）Press HOLD+POWER keys to enter into data access mode and display

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Unit 1 storage data automatically; and then press HOLD key again to turn
the page of stored data; NULL will display when there is no data in stored
in the memory, press POWER key to exit data access mode.
3）After entering into data access mode, press HOLD key for more than 3
seconds will clean up all stored data; when the leaker displaying “dEL”
symbol, it means that it has finished cleanup process, and then return to
measuring state automatically.
5. Upload data to computer
Before use this meter please insert USB driver software and the upload
software of this meter
Connect the computer and the meter with the USB connecting line
allocate with the meter, turn on the meter, run the software, enter into
data access mode, and read, save, report forms, and print the historical
data, etc. The more data has saved the more time it will cost when the
data read. The historical data can save into TXT or Excel format.
VI Function Quick Look Up
POWER Key Short Press
Power on/shutdown/exit
HOLD Key Shot Press
Data Holding/release/storage
HOLD Key Pressing
for more than 3s
Peak Holding
(at measuring mode)

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HOLD Key Pressing Press
for 3s
Clear Data(at access data mode)
HOLD Key + POWER Key
Data access /turn pages
(HOLD key)
VII Display Example and Meaning
1.---Measured leakage current is
0.25mA.
2.---Low battery, please change.
3.--- Measured leakage current is
0.25mA is held and automatically
stored unit ID is NO.03.
4. ---Access the unit 3 of the stored
Data

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VIII How to Change Battery
Warning! It is dangerous to carry out test when the
battery cover plate was not on its position.
Please pay attention to the polarity of battery to
avoid damaging the leaker.
Chang the low battery in time
If you expect not to use the meter for a long time,
please get off the battery to storage.
1）“ ” symbol means the battery is undercharge and need to be
replaced.
2）Press POWER key to shut down the leaker; before opening the battery
cover, please confirm the leaker is in off position, and then replace
with qualified new battery; special attention shall be paid to the
polarity of battery; at last, cover battery cover plate.

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IX Accessories
Clamp tester
1 pc
USB Com cable
1 pc
Software
1 disk
Battery（6F22 9V）
1 pc
User Manual
1 copy
Warranty card / Certification
1 copy

Your Testing Specialist