ANENG MH15 Digital Ohmmeter Insulation Resistance Meter User Manual

1. Introduction

This instrument is an insulation resistance tester powered by batteries, which can be used to measure AC/DC voltage, resistance, audible continuity, diode, and insulation resistance. When measuring insulation resistance, there are four test voltages to choose from: 100V, 250V, 500V, and 1000V. This instrument has functions such as polarity indication, over range indication, data hold, and automatic hold. Easy to use, it is a precise measuring instrument.

2. Safety Information

WARNING: To avoid possible electric shock or personal injury, and to avoid possible damage to the Meter or to the equipment under test, adhere to the following rules:

• Before using the Meter, inspect the case. Do not use the Meter if it is damaged or the case (or part of the case) is removed. Look for cracks or missing plastic. Pay attention to the insulation around the connectors.
• Inspect the test leads for damaged insulation or exposed metal. Check the test leads for continuity.
• Do not apply more than the rated voltage, as marked on the Meter, between the terminals or between any terminal and grounding.
• The rotary switch should be placed in the right position and no any changeover of range shall be made during measurement is conducted to prevent damage of the Meter.
• When the Meter is working at an effective voltage over 60V in DC or 30V rms in AC, special care should be taken for there is danger of electric shock.
• Do not use or store the Meter in an environment of high temperature, humidity, explosive, inflammable and strong magnetic field. The performance of the Meter may deteriorate after dampened.
• When using the test leads, keep your fingers behind the finger guards.
• Disconnect circuit power and discharge all high-voltage capacitors before testing resistance, continuity or diodes.
• Replace the battery as soon as the battery indicator appears. With a low battery, the Meter might produce false readings that can lead to electric shock and personal injury.
• Remove the connection between the testing leads and the circuit being tested, and turn the Meter power off before opening the Meter case.
• When servicing the Meter, use only the same model number or identical electrical specifications replacement parts.
• The internal circuit of the Meter shall not be altered at will to avoid damage of the Meter and any accident.
• Soft cloth and mild detergent should be used to clean the surface of the Meter when servicing. No abrasive and solvent should be used to prevent the surface of the Meter from corrosion, damage and accident.
• The Meter is suitable for indoor use.
• Turn the Meter power off when it is not in use and take out the battery when not using for a long time. Constantly check the battery as it may leak when it has been using for some time, replace the battery as soon as leaking appears. A leaking battery will damage the Meter.

3. Product Overview and Panel Description

The ANENG MH15 features a clear LCD display and intuitive controls. Below is a diagram of the device with numbered components and their descriptions.

1. Display: LCD display screen with analog segments.
2. VΩ+ terminal: The connection terminal for the red probe for other measurements, except for insulation resistance measurement.
3. COM terminal: The connection terminal for the black probe for other measurements, except for insulation resistance measurement.
4. INS+ terminal: Insulation resistance measurement, red lead connection.
5. INS- terminal: Insulation resistance measurement, black lead connection.
6. BL button: Screen backlight on/off button.
7. RANGE button: Manually select the range.
8. LOCK key: Used to lock or unlock the insulation resistance measurement function. If the "LOCK" button is pressed first and then the "TEST" button is pressed again, the instrument will continue to measure the insulation resistance until the "LOCK" button is pressed again.
9. HOLD key: Press this key to hold or release data hold.
10. SELECT key: This key is used for selecting multifunctional measurement.
11. TEST key: Hold down this key to start or perform insulation resistance measurement, release this key to stop measurement, and maintain the final value.
12. Function/range switch: Used to select the desired function and turn on or off the instrument power.

4. Setup

4.1 Battery Installation

The ANENG MH15 requires six 1.5V AA batteries for power. To install, open the battery compartment cover on the back of the device. Insert the batteries, ensuring correct polarity. Close the cover securely.

4.2 Test Lead Connection

Connect the black test lead to the 'COM' jack and the red test lead to the 'VΩ+' jack for most measurements. For insulation resistance, connect the black probe to 'INS-' and the red probe to 'INS+'. Ensure alligator clips are securely attached to the test pens when needed.

5. Operating Instructions

5.1 General Operation

• Power On/Off: Turn the function/range switch (12) to the desired measurement function to power on the instrument. Turn to 'OFF' to power off.
• Backlight: Press the 'BL' button (6) to turn the screen backlight on or off.
• Range Selection: Press the 'RANGE' button (7) to manually select the measurement range. Hold for 2 seconds to return to auto-ranging.
• Data Hold: Press the 'HOLD' button (9) to freeze the current reading on the display. Press again to release.
• Auto Power Off: The instrument will automatically shut off after approximately 15 minutes of inactivity. Press any button to turn it back on. To disable auto-shutdown, hold 'SELECT' and turn the function switch from 'OFF' to any function.

5.2 Insulation Resistance Measurement

WARNING: Only measure non-charged objects. Disconnect power and discharge all capacitors before testing.

1. Connect the black probe to the 'INS-' terminal and the red probe to the 'INS+' terminal.
2. Set the function switch to the desired test voltage (100V, 250V, 500V, or 1000V). The screen will display '----'.
3. Connect the probes to the circuit under test.
4. Hold down the 'TEST' button (11) to start measurement. The screen will display ' ' and 'TEST' indicating high voltage output and ongoing measurement.
5. To continuously measure, press 'LOCK' (8) then 'TEST'. The measurement will continue until 'LOCK' is pressed again.
6. Read the resistance value on the screen.
7. Release 'TEST' to stop measurement. The measured object will be discharged through the instrument. Do not disconnect probes until fully discharged.

5.3 AC/DC Voltage Measurement

1. Connect the BLACK test lead to the 'COM' jack and the RED to the 'VΩ+' jack.
2. Set the function rotary to V~ (AC) or V- (DC) range.
3. Connect the test leads across the source or load to be measured.
4. Read the LCD display. The polarity of the RED lead connection will be indicated when making a DC measurement.

5.4 Resistance Measurement

1. Connect the BLACK test lead to the 'COM' jack and the RED to the 'VΩ+' jack.
2. Set the function rotary to Ω range.
3. Connect the test leads across the load to be measured.
4. Read the reading on the display. Note: When the resistance value of the resistor is greater than 1MΩ, the reading may take several seconds to stabilize, which is normal for high resistance measurements.

5.5 Diode Test

1. Connect the BLACK test lead to the 'COM' jack and the RED to the 'VΩ+' jack.
2. Set the function rotary to diode test range.
3. Press the 'SELECT' button to select diode test mode, and the ' ' symbol will appear as an indicator.
4. Connect the red test lead to the anode of the diode to be tested and the black test lead to the cathode. The Meter will show the approximate forward voltage of the diode. If the connections are reversed, 'OL' will be shown on the display.

5.6 Continuity Test

1. Connect the BLACK test lead to the 'COM' jack and the RED to the 'VΩ+' jack.
2. Set the function rotary to continuity test range.
3. Press the 'SELECT' button to select continuity test mode, and the '•)))' symbol will appear as an indicator.
4. Connect the test leads across the load to be measured. If the circuit resistance is lower than about 30Ω, the built-in buzzer will sound.

5.7 Capacitance Measurement

1. Connect the BLACK test lead to the 'COM' jack and the RED to the 'VΩ+' jack.
2. Set the function rotary to capacitance range.
3. Connect the test leads across the capacitor, observing polarity. Remember to short-circuit the capacitor to discharge it before testing.
4. Read the capacitance value on the display.

6. Specifications

6.1 General Characteristics

• Display: 3 5/6 LCD, 6000 counts, updates 2~3/sec
• LCD size: 65 x 37mm
• Polarity Indication: "-" displayed automatically
• Over-range Indication: "OL" displayed
• Low Battery Indication: "" displayed
• Range select: Auto or manual
• Operation temperature: 0°C to 40°C, ≤75%RH
• Storage temperature: -10°C to 50°C, ≤80%RH
• Battery type: size AAA 1.5V x 6 battery
• Dimension (H×W×D): 174 x 130 x 54mm
• Weight: Approx 580g (including battery)

6.2 Measurement Ranges and Accuracy

7. Maintenance

• Cleaning: Use a soft cloth and mild detergent to clean the surface of the Meter. Do not use abrasive cleaners or solvents.
• Battery Replacement: Replace batteries as soon as the low battery indicator appears to ensure accurate readings. For prolonged storage, remove the batteries to prevent leakage.
• Storage: Store the Meter in a dry environment, away from extreme temperatures, humidity, and strong magnetic fields.
• Service: Only use identical replacement parts for servicing. Do not alter the internal circuit of the Meter.

8. Troubleshooting

• "OL" Display: Indicates an over-range condition. This means the measured value exceeds the instrument's current range. Select a higher range or check for an open circuit.
• "Lo" Display: During insulation resistance measurement, this indicates the measured resistance is less than or equal to 0.1MΩ.
• Low Battery Indicator: If the battery symbol appears, replace the six 1.5V AA batteries immediately to avoid false readings.
• No Buzzer Sound in Continuity Test: If the item is unobstructed but no sound is heard, check if the resistance is above 30Ω.
• "OL" During Diode Test: This typically means the test leads are connected in reverse polarity to the diode.

9. User Tips

• For accurate capacitance measurements, always remember to short-circuit the capacitor to discharge it completely before connecting the test leads.
• When measuring high resistance values (above 1MΩ), allow a few seconds for the reading to stabilize for the most accurate result.
• Always verify the meter is functioning correctly by testing a known voltage or resistance before performing critical measurements.

10. Warranty and Support

For warranty information and technical support, please contact your retailer or the manufacturer directly. Refer to the official ANENG website for further assistance and updated documentation. A user manual in PDF format is available for download: ANENG MH15 User Manual (PDF).