Mastech MS5201 User manual

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DIGITAL INSULATION TESTER
OPERATOR’S MANUAL

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CONTENTS
1. SAFETY INFORMATION ……………1
1.1 PRELIMINARY ……………2
1.2 DURING USE ……………3
1.3 SYMBOLS ……………4
1.4 MAINTENANCE ……………5
2. DESCRIPTION ……………6
2.1 NAMES OF COMPONENTS ……………9
2.2 SWITCH AND BUTTONS ELUCIDATE ……………10
3. SPECIFICATIONS ……………11
3.1 GENERAL SPECIFICATIONS ……………11
3.2 ELECTRICAL SPECIFICATIONS ……………12
4. OPERATING INSTRUCTION ……………16

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4.1 SWITCH DISLOCATION ALARM ……………16
4.2 SOUND AND FLASH ALARM ……………16
4.3 READ HOLD ……………17
4.4 HAND OPERATING AND TIME MEASURING ……………17
4.5 PREPARATION FOR MEASUREMENT ……………18
4.6 MEASURING INSULATION RESISTANCE ……………19
4.7 MEASURING AC VOLTAGE ……………22
4.8 MEASURING DC VOLTAGE ……………24
4.9 MEASURING RESISTANCE ……………26
4.10 CONTINUITY TEST ……………27
5. MAINTENANCE ……………29
5.1 BATTERY REPLACEMENT ……………29
5.2 TEST LEADS AND TEST CLIPS REPLACEMENT ……………30
6. ACCESSORIES ……………31

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1. SAFETY INFORMATION
This meter has been designed in general to comply with IEC 348 and
according to IEC-1010 concerning about electronic measuring instruments
with an overvoltage category 1000V CAT ΙΙ, 600V CAT Шand pollution 2.
Follow all safety and operating instructions to ensure that the meter is used
safely and is kept in good operating condition.
Pay attention to cautions and warnings, which will inform you of potentially
dangerous procedures.
WARNING
To ensure safe operation, please follow the directions in this section
carefully.
Electricity can cause severe injuries even with low voltages or currents.
Therefore it is extremely important that you read the following information
before using this Insulation Tester.

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1.1 PRELIMINARY
1.1.1 When using the meter, the user must observe all normal safety rules
concerning:
•Protection against the dangers of electrical current
•Protection of the meter against misuse
1.1.2 When the meter is delivered, check that it has not been damaged in
transit.
1.1.3 When poor condition under harsh preservation or shipping conditions
caused, inspect and confirm this meter without delay.
1.1.4 test leads or test clips must be in good condition. Before using verify
that the insulation on test leads or test clips is not damaged and/or the
leads wire is not exposed.
1.1.5 Full compliance with safety standards can be guaranteed only if used
with test leads or test clips supplied. If necessary, they must be

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replaced with the same model or same electric ratings.
1.1.6 This meter must only be used by a competent trained person and in
strict accordance with the operator’s manual.
1.2 DURING USE
1.2.1 Never exceed the protection limit values indicated in specifications for
each range of measurement.
1.2.2 When the meter is linked to a measurement circuit, do not touch
unused terminals.
1.2.3 Do not measure voltage if the voltage on the terminals exceeds 1000V
above earth ground.
1.2.4 Always be careful when working with voltages above 60V DC or 30V
AC rms, keep fingers behind the probe barriers while measuring.
1.2.5 Never connect the meter leads across on live circuits while the function
switch is in the insulation resistance, resistance or continuity mode.

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1.2.6 Ensure all circuits are de-energized before measuring.
1.2.7 Before rotating the range switch to change ranges, disconnect test
leads from the circuit under test.
1.2.8 If any faults or abnormalities are observed, the meter can not be used
any more and it has to be checked out.
1.2.9 Never use the meter unless the rear case is in place and fastened fully.
1.2.10 Please do not store or use meter in areas exposed to direct sunlight,
high temperature, humidity or condensation.
1.3 SYMBOLS
Important safety information, refer to the operating manual.
Double insulationProtection classΙΙ.
Earth ground
Low Battery
~ AC (alternating current)

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DC (direct current)
Continuity Buzzer
1.4 MAINTENANCE
1.4.1 Please do not attempt to adjust or repair the meter by removing the rear
case while voltage is being applied. A technician who fully understands
danger involved should only carry out such actions.
1.4.2 Before opening the battery cover of the meter, always disconnect test
leads or test clips from all sources of electric current.
1.4.3 Always set the function switch to the OFF position when the meter is
not in use.
1.4.4 If the meter is to be stored for a long period of time, the batteries should
be removed to prevent damage to the unit.
1.4.5 Do not use abrasives or solvents on the meter, use a damp cloth and
mild detergent only.

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2. DESCRIPTION
- This meter has the function of
sound and flash alarm. If the
function switch and range
switch is out of place, you will
hear a humming sound per
two seconds from the inside
alarming system. This
protection provides for meter
to avoid damage by operation
improperly.
- In measurement, the test
button is pressed, the meter’s

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alarming system will give out a humming sound (per two seconds), and the
red high voltage output indicator is flashing, which warns the operator to
pay attention to the high output voltage, and avoid getting electric shock.
- Overload protection and low battery indication is provided.
- This meter is a portable professional measuring instrument with large LCD.
- This meter has function of data hold.
- When using, it can show ranges engineering unit enunciators measuring
results.
- A double rotary switch is used to select functions and ranges.
- Test button with lock function.
- Releasing the test button automatically will discharge the capacitance of a
circuit under test.

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2.1 NAMES OF COMPONENTS (See Fig 3)
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High Voltage Output Indicator
2
LCD Display
3
Panel
4
Test Button
5
Data Hold Switch (D-H)
6
Function Switch
7
Range Switch
8
HIGH Jack
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LOW Jack
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Battery Cover
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Case

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2.2 SWITCH AND BUTTONS ELUCIDATE
•Function Switch
This switch is used to select measure mode and the switch of power.
•Range Switch
This switch is used to select desired ranges.
•Test Button
This Button is used to the insulation resistance measurements.
•Data Hold Switch
This switch is used to the switch of data hold

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3 SPECIFICATIONS
Accuracy is specified for a period of year after calibration and at 18to 28
64°F to 82°Fwith relative humidity to 75%.
3.1 GENERAL SPECIFICATIONS
3.1.1 Max. Voltage Between Terminals And Earth Ground: 1000V DC or AC
3.1.2 Measuring method: Dual-slope integration A/D converter
3.1.3 Sampling Time: approx. 0.4 second
3.1.4 Display: 22mm LCD
3.1.5 Max. Show Value: 1999 (3 1/2)
3.1.6 Polarity Indication: ‘-’indicates negative polarity.
3.1.7 Overrange Indication: Display ‘1’ or ‘-1’
3.1.8 Unit showing: showing of function and electrical capacity.
3.1.9 Power Supply: 1.5V ×6 (size AA) batter (recommended to use the
alkaline or heavy duty battery.)

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3.1.10 Power Consumption:
Approx. 5mADC1000VAC750V200Ω
Approx. 30mA200MΩ/250V
Approx. 50mA200MΩ/500V
Approx. 100mA2000MΩ/1000V
3.1.11 Low Battery Indication: ‘ ’ displayed
3.1.12 Operating Temperature: 0to 4032°F to 104°F
3.1.13 Operating Humidity: ≤85%RH
3.1.14 Storage Temperature: -10to 5010°F to 122°F
3.1.15 Dimension: 192×122×55 mm
3.1.16 Weight: Approx. 545gincluding battery
3.2 ELECTRICAL SPECIFICATIONS
Circumstance Temperature: 23±5Relative Humidity:<75%

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3.2.1 Insulation Resistance
Range 200MΩ/250V 200MΩ/500V 2000MΩ/1000V
Test Voltage DC 250V±10% DC 500V±10% DC 1000V±10%
0 ~ 2000MΩMeasuring Ranges 0 ~ 200MΩ0 ~ 200MΩ
0 ~ 1000MΩ1000 MΩ~ 2000MΩ
Accuracy ±3.0% rdg ±5 digits ±5.0% rdg ±5 digits
Range 200MΩ/250V 200MΩ/500V 2000MΩ/1000V
Output Voltage on Open Circuit 250V ±10% 500V ±10% 1000V ±10%
Minimum Output Voltage 225V at 0.25MΩ450V at 0.5MΩ900V at 1MΩ
Test Current (approx.) 1mA at 0.25MΩ1mA at 0.5MΩ1mA at 1MΩ
Output Short Circuit Current ≤2.5mA

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3.2.2 AC Voltage
Range Resolution Accuracy
700V 1V ±1.2% of rdg + 5 digits
- Input Impedance: 10MΩ
- Maximum Input Voltage: 700V rms AC or 1000V DC
- Frequency Range: 40 to 400Hz
- Response: Average, calibrated in rms of sine wave
3.2.3 DC Voltage
Range Resolution Accuracy
1000V 1V ±0.8% of rdg + 3 digits
- Input Impedance: 10MΩ
- Max. Input Voltage: 1000V DC or 700V rms AC

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3.2.4 Resistance
Range Resolution Accuracy
200Ω0.1Ω±1.0% of rdg + 3 digits
- Open circuit voltage approximate 2.5V
- Overload Protection: 250V DC or rms AC
3.2.5 Continuity
Range Function
Built-in buzzer will sound, if resistance is lower than 50Ω.
- Open circuit voltage approximate 2.5V
- Overload Protection: 250V DC or rms AC

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4. OPERATING INSTRUCTION
4.1 SWITCH DISLOCATION ALARM
When using for measuring AC voltage, DC voltage, resistance and continuity
test, you must rotate the function switch to “200Ω,1000V , 700V~” ,
rotate the range switch to “ 200Ω700V~ 1000V ” ; measuring
insulation resistance, you must rotate the function switch to “MAUN.LOCK
1min.LOCK 2min. LOCK 4min” . Otherwise, the inside alarm system will
give out a humming sound per two seconds. The indicator shows random
reading.
4.2 SOUND AND FLASH ALARM
In insulation range, the test button is pressed, the inside alarming system will
send out a humming sound per two seconds, also the right red high voltage
output indicator of the LCD flashes.

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4.3 READ HOLD
If you need data hold when measuring, you can put on “HOLD”, it will hold
the reading and the showing of the LCD will be locked. If you put the switch
again, data hold is not continuing.
4.4 HAND OPERATING AND TIME MEASURING
In insulation range, the function switch is rotated to “MAUN.”, the meter will
be operated by hand. Once press the test button, the measurement begins; If
there is a long-time measurement, you can press the test button and rotate it
counter clockwise to lock position. The function switch is rotated to “LOCK
1min., LOCK 2min., LOCK 4min.”, then press the green test button, which will
measure timely for one minute, two minutes and four minutes. In this course,
if you want to stop measurement, you can rotate the function switch to