HT4011 Clamp Meter User Manual

1. Precautions and Safety Measures

The instrument is designed in compliance with directive IEC/EN61010-1 for electronic measuring instruments. For your safety and to prevent instrument damage, carefully follow the procedures in this manual and pay close attention to notes preceded by the ⚠️ symbol.

Before and after measurements, observe the following:

• Do not perform voltage or current measurements in humid environments.
• Do not perform measurements in the presence of gas, explosive materials, flammables, or in dusty environments.
• Avoid contact with the circuit being measured if no measurements are being carried out.
• Avoid contact with exposed metal parts, unused measuring probes, or circuits.
• Do not perform measurements if anomalies like deformation, breaks, substance leaks, or absence of display are found.
• Pay special attention when measuring voltages higher than 20V due to the risk of electrical shock (⚡).

Symbols used in this manual and on the instrument:

• ⚠️: Warning - observe instructions; improper use can damage the instrument or its components.
• ⚡: High voltage danger - electrical shock hazard.
• [Double-insulated]: Double-insulated meter.
• ~: AC voltage or current.
• =: DC voltage.
• ⏚: Connection to earth.

1.1. Preliminary Instructions

• Designed for environments of pollution degree 2.
• Suitable for CURRENT and VOLTAGE measurements on installations with measurement category CAT III 600V (see § 1.4 for definition).
• Follow standard safety rules to protect the user and the instrument.
• Use only supplied leads; ensure they are in good condition and replaced with identical models if necessary.
• Do not test circuits exceeding specified current and voltage limits.
• Check that the battery is correctly inserted.
• Before connecting test leads, ensure the switch is correctly set.
• Verify that the LCD display and the switch indicate the same function.

1.2. During Use

Please read the following recommendations and instructions carefully:

CAUTION: Failure to comply with caution notes may damage the instrument, its components, or endanger the operator.

• Before activating the switch, remove the conductor from the clamp jaw or disconnect test leads from the circuit under test.
• When connected to the circuit, do not touch any unused terminal.
• Avoid measuring resistance if external voltages are present; excessive voltage can cause malfunction.
• When measuring current with clamp jaws, first remove test leads from input jacks.
• During current measurement, nearby currents may affect precision.
• For accurate current measurement, position the conductor as close to the middle of the clamp jaw as possible.
• If the measured value or sign remains unchanged, check if the HOLD function is enabled.

1.3. After Use

• When measurement is complete, switch OFF the instrument.
• If the instrument will not be used for a long period, remove the battery.

1.4. Definition of Measurement (Overvoltage) Category

Standard "IEC/EN61010-1" defines measurement categories. Circuits are divided as follows:

• Measurement category IV: Measurements at the source of the low-voltage installation (e.g., electricity meters, primary overcurrent protection devices).
• Measurement category III: Measurements on installations inside buildings (e.g., distribution boards, circuit breakers, wiring, junction boxes, switches, socket-outlets, industrial equipment).
• Measurement category II: Measurements on circuits directly connected to the low-voltage installation (e.g., household appliances).
• Measurement category I: Measurements on circuits not directly connected to MAINS (e.g., specially protected MAINS-derived circuits). Transient stresses can be variable.

2. General Description

The instrument performs the following measurements:

• DC and AC voltage up to 600V
• AC current up to 400A
• Resistance and continuity test with buzzer
• Capacitance
• Frequency with leads
• Duty Cycle
• Diode test
• Temperature with K probe
• Detection of AC voltage presence (contact and non-contact) with built-in sensor.

Functions are selected via an 8-position rotary switch (including OFF). The instrument also features HOLD, MODE, Hz%, and REL keys. Refer to § 4.2 for their use. The LCD display shows the selected quantity, unit, and enabled functions.

2.1. Measuring Average Values and TRMS Values

Alternating quantity measuring instruments are divided into two families:

• AVERAGE-VALUE meters: Measure the wave value at fundamental frequency (50/60 Hz).
• TRMS (True Root Mean Square) VALUE meters: Measure the TRMS value of the quantity.

For sinusoidal waves, both families yield identical results. For distorted waves, TRMS meters provide higher values as they measure the entire wave including harmonics, while average-value meters measure only the fundamental wave.

2.2. Definition of True Root Mean Square Value and Crest Factor

The root mean square (RMS) value of current is defined as the equivalent DC current that dissipates the same energy in a resistor over a period.

The Crest Factor (CF) is the ratio between the Peak Value and the RMS value of a signal. For a pure sinusoidal wave, CF = √2 ≈ 1.41. Distortion increases the Crest Factor.

3. Preparation for Use

3.1. Initial Checks

The instrument is checked for electrical and mechanical integrity before shipping. While precautions are taken to prevent damage, it is recommended to check for damage incurred during transport. Contact the forwarding agent if anomalies are found. Verify that all components listed in § 6.3 are present; contact the dealer for discrepancies. For returns, follow instructions in § 7.

3.2. Instrument Power Supply

The instrument is powered by two 1.5V AAA LR03 batteries (included). The ? symbol on the display indicates a low battery. Replace batteries following § 5.2. The instrument features an Auto Power OFF function that switches it off approximately 30 minutes after the last operation (cannot be disabled).

3.3. Calibration

The instrument's performance is guaranteed for 12 months, based on the technical specifications in this manual.

3.4. Storage

To ensure measurement precision after long storage under extreme environmental conditions, allow the instrument to return to normal conditions (see § 6.2.1).

4. Operating Instructions

4.1. Instrument Description

4.1.1. Description of the Controls

Fig. 1: Instrument description

• 1. Inductive clamp jaw
• 2. AC voltage detector (non-contact)
• 3. Rotary selector switch
• 4. Jaw trigger
• 5. HOLD key
• 6. MODE key
• 7. REL key
• 8. Hz% key
• 9. LCD display
• 10. Input terminal COM
• 11. Input terminal V ⏚ CAP Hz% Temp

4.2. Description of Function Keys

4.2.1. HOLD Key

Pressing the HOLD key freezes the measured value on the display, showing "HOLD". This mode is deactivated by pressing the HOLD key again or operating the switch.

4.2.2. REL Key

When the switch is set to V, V, or AC current positions, the REL key zeros the displayed value for relative measurements. The first press saves the value as an offset, indicated by "REL". Subsequent readings show the current value minus the offset. This function is inactive for resistance, continuity, temperature, capacitance, duty cycle, and diode tests. Press REL again or turn the switch to exit.

4.2.3. Hz% Key

With the rotary switch set to V, V, or Hz, the Hz% key toggles between frequency (Hz) and duty cycle (%) measurements.

4.2.4. MODE Key

The MODE key selects resistance, continuity test (with buzzer), and diode test when the rotary switch is set to Ω. It also selects AC and DC voltage measurements when the switch is set to V, V, or Hz.

4.3. Description of Rotary Switch Functions

4.3.1. DC Voltage Measurement

CAUTION: Maximum input DC voltage is 600Vrms. Exceeding limits can cause electrical shock and instrument damage.

Fig. 2: Use of the clamp for DC voltage measurement

1. Select the V position.
2. Insert the red cable into input terminal V ⏚ CAP Hz% Temp and the black cable into input terminal COM (Fig. 2).
3. Position test leads at the desired points in the circuit. The display shows the voltage value.
4. The "O.L" symbol indicates overload status.
5. Refer to § 4.2 for HOLD and REL functions.

CAUTION:

• Due to high input impedance, the display may take time to zero.
• Changing values on an open display are normal and not an instrument fault.

4.3.2. AC Voltage Measurement

CAUTION: Maximum input AC voltage is 600V. Exceeding limits can cause electrical shock and instrument damage.

Fig. 3: Use of the clamp for AC voltage measurement

1. Switch on the instrument near an AC source. The red LED at the clamp's base (Fig. 1 – Part 2) should light up, indicating AC source presence.
2. Select the V, V, Hz position.
3. Insert the red cable into input terminal V ⏚ CAP Hz% Temp and the black cable into input terminal COM (Fig. 3).
4. Position test leads in the circuit. The display shows the voltage value.
5. The "O.L" symbol indicates overload status.
6. Refer to § 4.2 for HOLD and REL functions.

CAUTION:

• Due to high input impedance, the display may take time to zero.
• Changing values on an open display are normal and not an instrument fault.

4.3.3. Frequency and Duty Cycle Measurement

CAUTION:

• When measuring frequency with leads, maximum input AC voltage is 600Vrms. Exceeding limits can cause electrical shock and instrument damage.
• When measuring frequency with the clamp, ensure all instrument input terminals are disconnected.

Fig. 4: Use of the clamp for frequency measurement and duty cycle

1. Select position V, V, Hz for frequency measurement with leads.
2. Press the Hz% key to cycle through "Hz" for frequency or "%" for duty cycle measurement.
3. Insert the red cable into input terminal V ⏚ CAP Hz% Temp and the black cable into input terminal COM (Fig. 4 – left side). The display shows frequency (Hz) or duty cycle (%).
4. The "O.L" symbol indicates overload status.
5. Refer to § 4.2 for the HOLD function.

4.3.4. Resistance Measurement

CAUTION: Before measuring resistance, remove power from the circuit and discharge all capacitors.

Fig. 5: Use of the clamp for Resistance measurement

1. Select the Ω position.
2. Insert the red cable into input terminal V ⏚ CAP Hz% Temp and the black cable into input terminal COM.
3. Position test leads in the circuit (Fig. 5). The display shows the resistance value.
4. The "O.L" symbol indicates overload status.
5. Refer to § 4.2 for the HOLD function.

4.3.5. Capacitance Measurement

CAUTION: Before measuring capacitance, cut off power supply and discharge all capacitance in the circuit or capacitor.

Fig. 6: Use of the clamp for capacitance measurement

1. Select the CAP position.
2. Press the MODE key to cycle until "nF" is displayed.
3. Insert the red cable into input terminal V ⏚ CAP Hz% Temp and the black cable into input terminal COM.
4. Position test leads in the circuit (Fig. 6). The display shows the capacitance value. The analog graphic bar is deactivated during capacitance measurement.
5. The "O.L" symbol indicates overload status.
6. Refer to § 4.2 for HOLD and REL functions.

4.3.6. Continuity Test and Diode Test

CAUTION: Before measuring resistance, remove power from the circuit and discharge all capacitors.

Fig. 7: Use of the clamp for continuity test and diode test

1. Select the Ω position.
2. Press the MODE key to cycle until the "))" symbol is displayed for continuity test.
3. Insert the red cable into input terminal V ⏚ CAP Hz% Temp and the black cable into input terminal COM. Perform continuity test (Fig. 7 – left side). A buzzer sounds if resistance is below 30Ω.
4. Press the MODE key to select diode test. The "+" symbol appears.
5. For direct polarization, connect the red lead to the anode and the black lead to the cathode of the diode (Fig. 7 – right side). For reverse polarization, invert the leads.
6. Display values between 0.4V and 0.7V (direct) or "OL" (reverse) indicate correct connection. "0mV" indicates a short circuit, while "OL" in both directions indicates an interrupted device.

4.3.7. Temperature Measurement in °C and °F

CAUTION: Do not touch live surfaces with the temperature probe. Voltages higher than 30Vrms or 60VDC imply electrical shock hazard (⚡).

Fig. 8: Use of the clamp for temperature measurement

1. Select the Temp°C or Temp°F position.
2. Insert the K wire probe into input terminals V ⏚ CAP Hz% Temp and COM using the adapter, respecting polarity (Fig. 8). The display shows the temperature value.
3. Refer to § 4.2 for the HOLD function.

4.3.8. AC Current Measurement

CAUTION: Before any measurement, disconnect all test leads from the circuit and meter input terminals.

Fig. 9: Use of the clamp for AC current measurement

1. Select position 40A or 400A.
2. Insert the cable into the middle of the clamp jaws for accurate measurements. The display shows the AC current value.
3. The "O.L" symbol indicates overload status. Switch to a higher range if this occurs.
4. Refer to § 4.2 for HOLD and PEAK functions.

CAUTION: Displayed values when the instrument is not in measuring mode are normal and not an instrument fault.

5. Maintenance

5.1. General Information

1. The instrument is a precision device. Observe manual recommendations during use and storage to prevent damage or danger.
2. Do not use in high humidity or high temperatures. Avoid direct sunlight.
3. Always switch off the instrument after use. If not used for a long time, remove the battery to prevent leaks that could damage internal circuits.

5.2. Replacing the Battery

When the LCD displays the ? symbol, replace the battery.

CAUTION: Only expert technicians should perform this. Ensure all cables are removed from terminals or the tested cable from the clamp jaw before proceeding.

1. Turn the rotary switch to OFF.
2. Disconnect cables from terminals and the tested cable from the clamp jaw.
3. Loosen the battery cover screw and remove the cover.
4. Disconnect the battery from the connector.
5. Connect new batteries, observing polarity (see § 6.1.2).
6. Replace and fasten the battery cover.
7. Dispose of old batteries properly in designated containers.

5.3. Cleaning the Instrument

Use a soft, dry cloth. Never use wet cloths, solvents, or water.

5.4. End of Life

CAUTION: The ♻️ symbol indicates that the appliance, accessories, and battery must be collected and disposed of separately and correctly.

6. Technical Specifications

6.1. Technical Characteristics

Accuracy is calculated as ± [% reading + (number of digits x resolution)]. Specifications are valid at 18°C ÷ 28°C with relative humidity <75% RH.

AC Voltage (Autorange)

Integrated sensor for AC voltage detection: LED on for phase-earth voltage > 100V, 50/60Hz.

DC Voltage (Autorange)

AC Current

Resistance and Continuity Test (Autorange)

Continuity test current: < 0.5mA

Capacitance (Autorange)

Diode Test

Frequency with Leads (Autorange)

100μs ≤ Pulse width ≤ 100ms ; Pulse frequency: 100Hz ÷ 150kHz; Sensitivity >10Vrms

Duty Cycle (Autorange)

Temperature with K probe (Autorange)

(*) Accuracy of K-probe not considered

6.1.1. Reference Standards

• Safety: IEC/EN61010-1
• Insulation: Double insulation
• Pollution level: 2
• Max operating altitude: 2000m (6562 ft)
• Overvoltage category: CAT III 600V to ground

6.1.2. General Characteristics

• Mechanical characteristics: Size (L x W x H): 200 x 66 x 37mm; (8 x 3 x 1in). Weight (battery included): 205g (7 ounces). Max. cable diameter: 30mm (1in).
• Power supply: Battery type: 2 batteries x 1.5V AAA. Low battery indication: The display shows the ? symbol when battery voltage is too low. AutoPowerOff: after 30 minutes (may not be disabled).
• Display: Characteristics: 4 digit LCD max 4000 point, sign and decimal point. Sampling rate: 2 measurements per second. Conversion type: Mean value.

6.2. Environment

6.2.1. Environmental Conditions for Use

• Reference temperature: 18°C ÷ 28°C; (64°F ÷ 82°F)
• Operating temperature: 5 ÷ 40 °C ; (41°F ÷ 104°F)
• Allowable relative humidity: <80%RH
• Storage temperature: -20 ÷ 60 °C ; (-4°F ÷ 140°F)
• Storage humidity: <80%RH

This instrument satisfies the requirements of Low Voltage Directive 2006/95/EC (LVD) and of EMC Directive 2004/108/EC.

6.3. Accessories Provided

• Pair of 2mm test leads
• Adapter + K-type wire probe
• Carrying bag
• Batteries (not fitted)
• User manual

6.4. Optional Accessories

7. Service

7.1. Warranty Conditions

This instrument is warranted against material or manufacturing defects under general sales conditions. Defective parts may be replaced during the warranty period; the manufacturer reserves the right to repair or replace the product. Return transport to After-sales Service or Dealer is at the customer's charge, but shipment must be agreed in advance. Include a report stating the reason for return. Use original packaging; damage from non-original packaging is charged to the customer. The manufacturer is not responsible for injury to people or damage to property.

The warranty does not cover:

• Repair/replacement of accessories and batteries.
• Repairs due to incorrect use or use with non-compatible appliances.
• Repairs due to improper packaging.
• Repairs by unauthorized personnel.
• Modifications without manufacturer's explicit authorization.
• Use outside specifications or the instruction manual.

Manual content cannot be reproduced without authorization. Products are patented and trademarks registered. Manufacturer reserves the right to change specifications and prices due to technological improvements.

7.2. Service

If the instrument malfunctions, check battery and cable conditions first. If issues persist, ensure the product is operated according to this manual. For returns, transport is at the customer's charge, and shipment must be agreed in advance. Include a report stating the reason for return. Use original packaging; damage from non-original packaging is charged to the customer.