MEWOI MEWOI400 User manual

1
Wireless H/L Hook Type Current Meter
MEWOI400,MEWOI400B
USER MANUAL
www.mewoi.com

Table of contents
Safety instructions........................................................................ 3
Ⅰ．Introduction..................................................................................... 4
Ⅱ．Type difference................................................................................. 5
Ⅲ．Technical specification .................................................................... 5
Ⅳ．Structure .......................................................................................... 8
Ⅴ. Operation ........................................................................................... 9
1．Basic operations.......................................................................... 9
2．Test............................................................................................. 10
Ⅵ．Battery management......................................................................11
Ⅶ．Packaging list................................................................................. 12

Safety instructions
●Danger of high voltage！Operators must receive strict training and obtain relevant
national high-voltage operation certification before using this instrument for field
tests.
●Operators must fully understand the manual instructions and master how to operate
this instrument before carrying out field tests.
●When the voltage on tested power line exceeds 600V, the instrument should be
connected to insulation rod before used,
●It is forbidden to use this instrument to test the bare conductor or bus rod with
a voltage over 35kV (it can test the bare conductor or bus rod with a voltage
under 35kV, or cable with safe insulation sheath with a voltage under 100kV).
●The maximum outer diameter of conductor or cable this instrument can test is
168mm, and the maximum size of bus this instrument can test is
168mm×245mm.
●Please use special insulation rod to connect this instrument.
●After the instrument is connected to stretching insulation rod, it should be placed and
fetched gently to avoid impact with the ground and damage.
●Please do not place and store the instrument in high-temperature, humid premises
with moisture condensation under direct sunlight for a long term.
●Please charge the battery regularly or take it out if the instrument is not used for

long.
●Please note the polarity when the battery is replaced. If it cannot be replaced, please
contact the manufacturer.
●Disassembly and repair of this instrument should be operated by staff with
authorized qualification, and this instrument should be maintained regularly.
●If this instrument and other components are damaged, please stop using this
instrument.
●If safety risk will be incurred by the continuous operation of this instrument, please
stop using this instrument right away and seal it immediately, and agency with
authorized qualification should deal with the safety risk.
●It is advised that at least one insulation intensity test should be carried out on the
insulation rod every year (AC between two ends after 110kV/rms insulation rod is
totally stretched.)
●Patrol inspection method on electricity leakage of multi-conductor cable: hook
the instrument onto the cable, and patrol inspect alongside the cable. If there
is a large current displayed on the receiver, which suddenly changes into a
small or zero current, this point on the cable is subject to electricity leakage.

Ⅰ. Introduction
MEWOI400(400B) wireless high-low voltage hook amperemeter consists
of large-aperture hook instrument, wireless receiver and extensible insulation rod.
The iron core of hook instrument is made by new materials: portable,
high-precision, wide measurement range and good linearity. When the instrument
is connected to extensible insulation rod, it can test the leakage current, current,
frequency and load of bare conductor or bus rod under 35kV, or cable with safe
insulation sheath under 110kV. Besides, it is especially suitable for electricity
leakage patrol inspection and transformer load detection of downhole and outdoor
multi-conductor thick cable. The straight wireless data reception distance is 150m,
and the current measurement can be selected between AC 0～6000A and 0～
20000A, the maximum outer diameter of conductor or cable which it can measure
is 168mm, and the maximum size of the busbar which it can measure is
168mm×245mm.
Hook instrument can be hanged onto the line to carry out tests, which saves
the physical efforts of operators. The receiver adopts 3.5-inch True Color LCD,
which provides intuitive and clear image interface display. The insulation rod is
portable and characteristic of moisture resistance, high-temperature resistance,
impact resistance, high insulation and extensibility. In addition, the instrument can

maintain and store the data. Thus, it is widely applied in current detection and
outdoor electrician operations in substations, power generation plants, industrial
and mining enterprises, detection stations and electrician repair departments.
Ⅱ.Type difference
Ⅲ. Technical specification
Type
Current measurement range
Remark
MEWOI400
AC 0～6000A
/
MEWOI400B
AC 0～20.0kA
Wider current measurement
range
Function
High-low voltage AC leakage current, current and frequency
test; iron core grounding current and transformer load test;
electricity leakage patrol inspection of downhole and
outdoor multi-conductor think cable
Power Supply
DC 3.7V chargeable lithium battery, USB charging portal,
working continuously for 10h
Testing method
Hook CT, which can be hanged onto the line for testing
Transmission
433MHz wireless transmission

method
Transmission
distance
Straight transmission distance about 150m
Display mode
3.5-inch True Color LCD display, press upper and lower
arrow button to adjust the backlight luminance
Tested line
diameter
Ф168mm Conductor or cable, or 168mm×245mm bus bar
Measurement
range
Current: AC 0～6000A or AC 0～20.0kA (50/60Hz
automatic)
Frequency: 45Hz～75Hz
Resolution
10mA；0.1Hz
Current
Accuracy
(23℃±5 ℃，
below 80%RH)
0.00A～99.9A: ±2%±5dgt
100A～6000A: ±3%±5dgt
6.00kA～20.0kA: ±4%±5dgt
Frequency
Accuracy
±1Hz
Gear shift
Automatic gear shifting
Size of
insulation rod
About 5m long after extended; about 1m long after drawn
back (5 nodes)
Data storage
9999 sets
Sampling Rate
2 times/s
Instrument size
Hook instrument: length width thickness
310mm×270mm×52mm
Receiver: length width thickness 250mm×100mm×40mm

Line voltage
Test bare conductor under 35kV, cable with safe
insulation sheath under 110kV (operate with insulation
rod)
Data
maintenance
Press HOLD button under testing mode to maintain the data,
and then press HOLD button again to cancel the
maintenance
Exit function
Press ESC button to exit from current interface and return to
the upper directory
Position error
No position error in Area A; about 0.2% increase in Area B;
about 2% increase in Area C
Data reference
After entering data reference mode, press arrow button to
refer to all the stored data
Overflow
display
Current measurement range overflow function: displayed by
“OL” symbol
No-signal
indicator
When the receiver does not receive the transmission signal,
it dynamically displays “----” symbol
Automatic
shutdown
About 15mins after startup, the instrument will be
automatically shut down to reduce battery consumption
Battery voltage
When the battery voltage is lower than 3.2V, the low battery
voltage symbol will be displayed to promote charging the
battery
Weight
Hook instrument: 496g(including battery)
Receiver: 395g(including battery)
Insulation rod: 1.45kg
Total weight: 11.5kg(including instrument box)

Ⅳ. Structure
1: Hook instrument
2: Online detection of fixation hole
3: Connector of insulation rod
4: Antenna
5: Charging portal
6: LCD
7: POWER source button
8: Receiver
9: Type sticking position
Working
humidity and
temperature
-10℃～40℃; below 80%Rh
Storage
humidity and
temperature
-10℃～60℃; below 70%R
Interference
No interference from other 433MHz signals
Insulation
intensity
Insulation rod: AC 110kV/rms(between both ends after 5
nodes of insulation rod are totally extended)
Hook instrument: 2000V/rms(between the connector of
insulation rod and the top end of hook instrument)
Receiver: 2000V/rms(before the front and back end of outer
shell)
Structure
Anti-dripping Type II

10: Working indication light
11: ESC exit button
12: HOLD button
13: Arrow button and ENTER confirm button
14: Extensible insulation rod handle
Ⅴ. Operation
1．Basic operation
Receiver and hook instrument are opened or closed by pressing POWER
button.
After the instrument is initiated, LED indication light is turned on to enter
testing mode. If LED flashes slowly after initiation, the battery of instrument is
shock in power and needs to be charged. During charging process, LED flashes
quickly. LED keeps flashing slowly 15mins after initiation to promote that the
instrument will automatically shut down. Press POWER button so that the
instrument can keep working.
After receiver is initiated, LCD displays. Press upper or lower arrow buttons
to adjust LCD backlight luminance. LCD flashes 15mins after the receiver is
initiated to promote that the receiver will automatically shut down. Press POWER
button so that the receiver can keep working.
Press HOLD button to lock and store the data. HOLD symbol is indicated
when data are locked. The instrument cant store up to 9999 sets of data.
Press arrow button to move the cursor or refer to data, press right or left arrow
buttons to select stepping value as 5, 10, 100 and 1000. Press upper or lower arrow
buttons to refer to stored data.
Press ENTER button to confirm carrying out current operation.
Press ESC button to exit from current director and return to upper menu.

Enter into data deletion mode, and select “Yes” and press ENTER button to
confirm deleting all the stored data. The data cannot be restored after deleted.
Please be cautious of operation.
2．Test
High voltage, extreme danger! Must be operated by
staff who has received training and obtained authorized
qualification. The operators must strictly follow the
safety rules. Or otherwise, there will be electric shock
hazard, which will cause personal injuries or equipment
damages.
Danger! It is forbidden to test bare conductor or bus
rod over 35kV. Or otherwise, there will be electric
shock hazard, which will cause personal injuries or
equipment damages.
Hang the instrument onto the conductor and place the conductor into Area A
of the instrument as shown in following figure. No position error in Area A; about
0.2% increase in Area B; about 2% increase in Are C.
Patrol inspection method of electricity leakage of multi-conductor cable: hook
the instrument onto the cable, and patrol inspect alongside the cable. If there is a
large current displayed on the receiver, which suddenly changes into a small or
zero current, this point on the cable is subject to electricity leakage.

●Hook the null line and live line (2 lines) together and then measure single-phase
leakage current of electrical appliance.
●Hook the grounding line (1 line) and then measure the leakage current of this
equipment grounding line.
●Hook three-phase four lines (4 lines) together to test the total leakage current.
●Hook the main line (1 line) and then measure the current in this main line.
ⅥBattery management
●Charge the battery timely, and charge the instrument battery once every three
months if the instrument is not used for long.
● Warning! It is forbidden to test when the battery coverplate is placed. Or
otherwise, safety risks will be incurred.
● Please note the battery polarity during battery replacement. Or otherwise, the
instrument might be damaged.
1. When the battery voltage is lower than 3.2V, please charge the battery timely. It
takes about 5h to charge the battery fully.
2. Before battery replacement, firstly confirm that the instrument is at shutdown
status, loosen the screw of battery coverplate, open the battery coverplate and
replace with new battery, Note the battery specification and polarity, place the
battery coverplate and tighten the screws.

3. Press POWER button to see if the instrument can be initiated normally. If it
cannot, please operate according to Step 2.
4. If the user cannot replace the battery, please contact with the manufacturer.
ⅦPackaging list
The contents of this user manual cannot serve as reasons for using the product for
special purposes.
Our company reserves the right to alter the contents of user manual. If it is altered,
no separate notice will be issued.
Hook instrument
1 set
Receiver
1 set
Antenna
2 pieces
Extensible insulation rod
1 piece
Instrument box
1 set
USB charging portal
1 piece
USB charging wire
1 piece
Lithium battery
2 batteries(inside the instrument)
User manual, repair guarantee card and qualification
license
1 set

Your Testing Specialist