MEWOI MEWOI68C User manual

Digital Insulation
Resistance Tester
USER MANUAL
1. Summary
The Digital Insulation Resistance Tester series have high performance, and safe
configuration and improved electro circuit. It is one new item which has more fully function,
higher precision, and easier operation. It’s also one quakeproof, dustproof and damp-proof
tester and can fit work environment of outdoor.
The output testing voltage can be changed between
100V/250V/500V/1000V/2500V/5000V for different item no. The resistance can reach
200GΩ; the tester also can measure alternating voltage.
This Tester apply for all kinds or electric equipment and insulation materials such as
transformer, electromotor, cable, switch, appliance, etc.
It is a perfect electrical testing meter.
2. Safety Notice
(1) Read this Operation Manual carefully before use it.
(2) This meter is designed in accordance with IEC publication 1010, pollution degree II and
installation category (over voltage category) II.
(3) Should not use it before close the back lid cause of the danger of electroshock.

(4) Check the insulation layer of the test pin lead.
(5) Don’t rotate switch when testing.
(6) When seeing “ ” on the LCD, means the battery voltage is low. Please replace the
battery or charge the battery by the battery charger to insure accurately testing.
3. Electric Symbols
Important hint
Care for high voltage
Double insulation
Low battery
VAC voltage
Ground (maximum permitted voltage between terminal
and ground).
4. Feature
(1) Low power consumed CMOS double integral A/D transforming IC, auto-checking to zero,
auto displaying polarity, displaying when low battery.
(2) LCD: 3 1/2 digits display with a max. reading of 1999
(3) Has function of holding data and displaying signal.
(4) LCD back light.
(5) Can use rotating switch when testing voltage.
(6) Voltage belowAC 750V can be tested.
(7) High voltage is on the rails when LED is on.
(8) Displaying when low battery.
(9) Drove by Battery not by hand.
(10) Auto switch the range when measuring resistance.
(11) With strong load, appox.1.0mA output short current.
(12) Perfect circuit protect, preventing damage by voltage shock effectively.
(13) Size of LCD: 68×55mm (Height of character is 35mm)
(14) Power: six battery 5# which is 1.5V (R6AA SUM-3)
(MEWOI68C, D, G)
(15) Size of shape: 218×122×75mm.
(16) Weight: 900g (contain battery).
(17) Environment:
Working temperature: 0～40°C,
relative humidity <80%.
Storage temperature: -10～50°C,
relative humidity <85%.
Temperature to ensure precision:
23 ±5°C, relative humidity <75%.
5. Technique Index
Accuracies are ±( % of reading + number in last digit ) for one year
Environment temperature: 23 ±5°C, Relative humidity <75%

Model
MEWOI68C
MEWOI68G
MEWOI68D
Voltage Max
5000V
2500V
1000V
Testing Rating
Voltage
500V/1000V/
2500V/5000V
250V/500V/
1000V/2500V
100V/250V/
500V/1000V
Output voltage
90～110% Testing Rating Voltage
Scale
1MΩ～
200GΩ
1MΩ～
20GΩ
1MΩ～
20GΩ
Accuracy
1MΩ～200MΩ: ±( 3.0%+5 )
200MΩ～10GΩ: ±( 5.0%+5 )
10GΩ～200GΩ: ±( 10.0%+5 )
Resolution
20MΩ: 10kΩ, 200MΩ: 100kΩ, 2000MΩ:
1MΩ, 20GΩ: 10MΩ, 200GΩ: 100MΩ
Scale of AC
voltage
1～750V
Accuracy
±( 2.0%+5 )
Resolution
1V
Frequency
response
40～400Hz
Note: When the measured resistance is less than 5MΩ in any rating test voltage, the
measuring time should not be more than 10 seconds.
Remark: Minimum measured resistance
Rating test voltage
Minimum measured
resistance
100V
1MΩ
250V
1MΩ
500V
1MΩ
1000V
2MΩ
2500V
2MΩ
5000V
8MΩ
Explaining: Minimum measured resistance means lower limit value of resistance which it
ensure the voltage of two extremity of measuring is less than 90% of rating test voltage.
6. Operation Sketch Map

(1) Mounting hole
(2) High voltage startup switch: TEST/STOP
(3) Data holding key: HOLD
(4) Rating voltage rotating switch
(5) Crust of meter
(6) Protective casing
(7) LCD
(8) Back light switch: LIGHT
(9) High voltage indicator light
(10) ACV measurement terminal COM
/ Shield input terminal for insulation
/ Battery charge negative pole
(11) EARTH input terminal (Insulation)
(12) ACV Input terminal
/ Battery charge positive pole
(13) LINE input terminal (Insulation)
7. Operating specification
(1) Safety notices
a. There is a possibility of causing an accident of electric shock. After the measurement of
insulation resistance is completed, be sure to discharge the high voltage charged in the
measuring object.
b. There is a risk of electric shock during the measurement. Be careful not to touch the
measuring terminal and measuring object during the measurement.
c. When the circuit is activated, make measurement after disconnecting the power
source.
d. Make measurement within the insulation resistance measuring range, and never
impress voltage from outside, or the tester will be destroyed.
e. Be sure to confirm the position of rotary switch and the connection of measuring lead
with the tester before starting the measurement.
f. When start the high voltage startup switch, there is a high voltage about 100V～5000V
between Land E, must not touch the bare part of meet and object be tested cause of the
danger of been shocked.
(2) AC voltage test
a. Don’t test up AC 750V voltage. It is Dangerous!
b. Connect the measuring Leads
Insert the red plug of lead with probe to measuring terminal “V”, and the black plug of
AC measuring lead to measuring terminal “COM”, respectively.
c. Connect to the measuring object
Using the rotary switch select the “750V” position. Connect the test pin of lead with
probe to the other side of measuring object, and the test pin of AC measuring lead to

another part of measuring object.
d. Then the digital display voltage is the AC voltage of the metrical object in fact.
(3) Insulation resistance testing
a. Connection of measuring lead
Insert the big plug of lead with probe to measuring terminal “L”, the plug of lead with clip to
measuring terminal “E”, and the black plug of AC measuring lead with a small clip to
measuring terminal “COM”, respectively.
b. Testing lead connected
The lead with the big measuring clip is the leads connected with the earth. The lead with the
high voltage’s probe is the highest-voltage leads. The lead with connecting in “COM” socket
is the shield leads meeting on the surface of the testing resource to preventing the surface
leak affecting testing resistance. Using the rotary switch select the “OFF”position, connect
the clip of lead to the other side of measuring object, and the AC measuring lead’s small clip
to the surface of measuring object.
c. Rating Voltage select
Select the Rating Voltage adapt to the insulation resistance you want to test .
Turn the rotating switch to the voltage segment needed.
d. Testing
Connect the probe to object, press the button “TEST/STOP”, “HV” indicator light, which
indicates measuring voltage happen.
After testing begins, the number displayed on LCD is the insulation value of object tested.
e. End
After the measurement completed, push down the switch of the “TEST/STOP” once
more .When the red LED off, means the output testing high voltage has been cut. Turn the
rotary switch to “OFF” position. If measure the contain nature load, please short the
residually electric of the testing resource first before move the testing leads.
(4) Data hold
On any range, press the “HOLD”key to lock display value, and the “HOLD”sign will
appear on the display, press it again to exit.
(5) Back light
On any range, press the “LIGHT”key to light the back light. The light can wink
automatically after approx. 10 seconds.
8. Battery replacement
1) When the battery voltage drop below proper operation range,
the “ ” symbol will appear on the LCD display and the
battery need to changed (or charge the battery by the charger).
2) Before changing the battery, set the selector switch to “OFF”position.
3) Open the cover of the battery cabinet by a screwdriver.
4) Replace the old battery with the same type battery.
5) Close the battery cabinet cover and fasten the screw.
Caution: Dispose the used batteries according to the rules, which are defined by each
community.
9. Maintenance
This is a precise instrument and needs careful maintenance.
a. Don’t open the back lid at will. Don’t use it if the back lib not fixed.
b. Put it in the place dry and airiness if the meter will be leave unused for long term.
c. Don’t change the inner circuit at will or the meter maybe out of use.
If there is any problem, contact with us please.
10. Accessories

a. The measuring lead of the insulation tester: 1 set
b. User’s manual: 1 piece
Above picture and content just for your reference. Please be subject to the actual
products if anything different or updated. Please pardon for not informing in
advance.
Your Testing Specialist