Operating Instruction for CEM DT-398H AC TRMS Leakage Clamp Meter

1. Introduction

The CEM DT-398H is a handheld AC TRMS Leakage Clamp Meter designed for accurate and efficient electrical measurements. It features a negative display LCD, turntable, key, and knob with backlight indication, making it easy to operate even in dark conditions. This instrument is suitable for various applications in family, school, lab, and other environments where high current measurement is required.

This manual provides essential information for the safe and effective use of your DT-398H Clamp Meter. Please read it thoroughly before operation.

2. Safety Information

2.1. International Safety Symbols

• ⚠ This symbol, adjacent to another symbol or terminal, indicates the user must refer to the manual for further information.
• ⚠ This symbol, adjacent to a terminal, indicates that, under normal use, hazardous voltages may be present.
• □ Double Insulation
• ⚡ Application around and removal from uninsulated hazardous live conductors is permitted.
• CE The CE marking indicates conformity with European directives, in particular LVD and EMC.
• ♻ The rubbish bin with a line through it indicates that, in the European Union, the product must undergo selective disposal in compliance with Directive WEEE 2002/96/EC. This equipment must not be treated as household waste.

2.2. Safety Notes

WARNINGS:

• Do not exceed the maximum allowable input range of any function.
• Set the function switch OFF when the meter is not in use.
• Remove the battery if the meter is to be stored for longer than 60 days.
• Set the function switch to the appropriate position before measuring.
• Avoid contact with exposed metal parts, unused measuring terminals, circuits, etc.

CAUTIONS:

• Improper use of this meter can cause damage, shock, injury or death.
• Read and understand this user manual before operating the meter.
• Inspect the condition of the test leads and the meter itself for any damage before operating the meter; repair or replace any damage before use.
• Use great care when making measurements if the voltages are greater than 25VAC rms or 35VDC, as these voltages are considered a shock hazard.
• If no measurement is made, avoid contact with the test circuit.
• If the equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be impaired.
• Designed for use in environments with a pollution level of 2, this instrument can be used for current measurement and for devices using CAT III 300V.

2.3. Input Limits

3. Features

• Auto Power OFF
• TRMS measure
• 1µA high resolution
• LPF Mode eliminates noise interference
• Peak Hold value measure
• Data Hold and Flash Light
• Negative LCD display
• Turntable, Key and Knob with backlight indication

4. Meter Description and Setup

4.1. Meter Components

Familiarize yourself with the different parts of the DT-398H Clamp Meter:

Image: CEM DT-398H Clamp Meter showing its main components and usage scenarios, including measuring current in an electrical panel and using the flashlight function.

1. Leakage Clamp
2. Clamp Trigger
3. LCD Display
4. Backlight Button
5. Rotary Indicator Light
6. Rotary Function Switch
7. Knob Light Indicator
8. LPF Button
9. PEAK Button
10. HOLD/Flashlight Button
11. Flashlight
12. Battery Cover

4.2. Symbols Used on LCD Display

The LCD display uses various symbols to indicate the meter's status and measurement modes:

Image: The CEM DT-398H Clamp Meter's digital display, illustrating the 'mA' unit and other indicators.

1. Auto Power Off
2. milli (Current)
3. Amperes (Current)
4. Measurement Display Digits
5. Low Pass Filter (LPF)
6. Data Hold
7. PEAK Hold
8. Auto Range mode
9. Low Battery
10. Alternating Current

5. Operating Instructions

5.1. AC Current Measurement

WARNING:

Ensure that the test leads are disconnected from the meter before making current clamp measurements.

1. Set the Function switch to the 100A Range. If the approximate range of the measurement is not known, select the highest range then move to the lower ranges if necessary.
2. Use the Rotary Function switch to select AC 6mA/60mA/600mA/6A/60A/100A Range.
3. Use the LPF Button to select Low Pass Filter mode.
4. Select AC Current Test, press the PEAK Button to turn Peak Hold test. The LCD will display "P & H".
5. Press the trigger to open the jaw, fully enclose only one conductor. For optimum results, center the conductor in the jaw.
6. The clamp meter LCD will display the reading.

Image: Correct method of measuring AC current with the clamp meter, showing a single conductor enclosed in the jaw.

Correct Measurement

Image: Incorrect method of measuring AC current, showing multiple conductors enclosed, which will lead to inaccurate readings.

Incorrect Measurement

5.2. Leakage Current Measurement

The leakage current can be measured using direct or indirect methods in single-phase and three-phase systems.

5.2.1. Single-Phase System (Direct Method)

The leakage current is measured directly by enclosing both the Neutral (N) and Live (L) conductors in the clamp.

Image: Diagram illustrating the direct method of leakage current measurement in a single-phase system, with the clamp meter enclosing both N and L conductors.

5.2.2. Three-Phase System (Direct Method)

For a three-phase system, the direct method involves clamping all three live conductors (L1, L2, L3) and the Neutral (N) conductor simultaneously.

Image: Diagram illustrating the direct method of leakage current measurement in a three-phase system, with the clamp meter enclosing L1, L2, L3, and N conductors.

5.2.3. Three-Phase System (Indirect Method)

The indirect method for three-phase systems involves clamping only the three live conductors (L1, L2, L3).

Image: Diagram illustrating the indirect method of leakage current measurement in a three-phase system, with the clamp meter enclosing only L1, L2, and L3 conductors.

5.3. Function Buttons

• LPF (Low Pass Filter): Press and hold the LPF Button to activate LPF TEST; the LCD will display "50-60Hz". Holding the LPF Button to turn the system on will cancel the auto power off function.
• HOLD/Flashlight: Press to freeze the LCD reading (HOLD icon appears). Press again to return to normal operation. This button also controls the flashlight: press once to turn on, press again to turn off. The backlight is also controlled by this button for better visibility.
• PEAK: In AC current test mode, press the PEAK Button to measure peak maximum and peak minimum values.
• Backlight: Press the turntable, key, and knob Backlight Button to turn the backlight on. Press again to turn it off.
• Automatic Power OFF: To conserve battery life, the meter automatically turns off after approximately 15 minutes. To turn it back on, move the function switch to the OFF position and then to the desired function. Holding the LPF Button during power-on will disable auto power off.

6. Maintenance

WARNING:

To avoid electrical shock, disconnect the meter from any circuit, remove the test leads from the input terminals, and turn OFF the meter before opening the case. Do not operate the meter with an open case.

6.1. Cleaning and Storage

• Periodically wipe the case with a damp cloth and mild detergent.
• Do not use abrasives or solvents.
• If the meter is not to be used for 60 days or more, remove the battery and store it separately.

6.2. Battery Replacement

1. Contrarotate the Battery Door Lock 180 degrees to open the battery door.
2. Replace with 3x1.5V AAA batteries.
3. Secure the battery compartment.

7. Troubleshooting

If you encounter issues with your CEM DT-398H Clamp Meter, please refer to the following common troubleshooting steps:

• No Display/Power On: Check if the batteries are correctly installed and have sufficient charge. Replace batteries if necessary. Ensure the function switch is not in the OFF position.
• Inaccurate Readings: Verify that the correct measurement function and range are selected. Ensure the clamp is properly closed around a single conductor for current measurements. Check for external electromagnetic interference.
• "OL" Display: This indicates an over-range condition. Select a higher measurement range or ensure the input is within the meter's capabilities.
• "Low Battery" Indicator: Replace the AAA batteries as soon as possible to ensure accurate measurements and proper operation.
• Backlight/Flashlight Not Working: Check battery level. If the issue persists after battery replacement, contact customer support.

For persistent issues, please refer to the Warranty and Support section.

8. Specifications

8.1. Technical Specifications

Maximum input: 120A

Accuracy specified from 5% to 100% of the measuring range.

Frequency Response: 0.000mA-10A (50 to 1kHz); 10A-60A (50 to 400Hz); 60A-100A (50 to 60Hz).

AC Bandwidth: 50 to 1000Hz (Sine); 50/60Hz (All wave).

PEAK Current Maximum Input: 120A 40ms.

Over range protection: Maximum input 120A.

Accuracy Specified from 5% to 100% of the measuring range.

PEAK Current Maximum Input: 120A 40ms.

Low Pass Filter Frequency: <100Hz.

8.2. General Specifications

9. User Tips

Based on the provided customer feedback and Q&A, there are no specific user tips related to the operation or features of the CEM DT-398H Clamp Meter. The available Q&A primarily addresses payment security, which is outside the scope of product usage tips.

Always ensure the meter is clean and stored properly to maintain its accuracy and longevity.

10. Warranty and Support

For warranty information, technical support, or service inquiries, please contact the manufacturer or your authorized dealer. Keep your purchase receipt as proof of purchase.

Refer to the official CEM website or product packaging for the most up-to-date warranty terms and contact details.

11. Company Information

SHENZHEN EVERBEST MACHINERY INDUSTRY CO.,LTD (Brand :CEM) was established in 1991. It is a high-tech enterprise specialized in R&D, production and marketing of various professional measuring instruments.

CEM is located in Shenzhen, China, with more than 1,000 employees, over 100 engineers, 13 production plants, 32 production lines, and advanced production equipment.

Main products include thermal imagers, infrared thermometers, body thermometers, digital multimeters, clamp meters, insulation testers, electrical testers, coating thickness testers, video borescopes, laser distance meters, dataloggers, temperature & humidity meters, moisture meters, light meters, sound level meters, anemometers, gas detectors, particle counters, automotive digital multimeters, and testers, etc.

Quality and Safety Certifications: The company's management and regulations strictly follow ISO9001 standards, and products are in full compliance with international quality certification standards CE, UL, RoHS.

Video: An introduction to CEM, highlighting their commitment to precision measurement, innovation, quality, and their wide range of products across various industries.