1. Introducció
This user manual provides comprehensive instructions for the safe and effective operation of the HT-Instruments COMBI 420 Multifunction VDE 0100 Tester. The COMBI 420 is an advanced and versatile instrument designed for quick and easy verification of electrical installations. It performs tests in accordance with VDE (EN61557) parts 2, 3, 4, 6, and 7, and includes single-phase network analysis capabilities. Please read this manual thoroughly before using the device to ensure proper functionality and user safety.
2. Informació de seguretat
Avís: Electrical testing can be hazardous. Always follow local safety regulations and procedures. Failure to do so may result in injury or damage to the equipment.
- Ensure the device is in good working condition before each use.
- Do not use the device if it appears damaged or if any part of the insulation is compromised.
- Always wear appropriate personal protective equipment (PPE) when performing electrical tests.
- Verify that the test leads and accessories are rated for the voltage and current levels being measured.
- The COMBI 420 is designed for safety according to IEC-1010-1, CAT III 415 V. Adhere to these ratings.
- Never attempt to open or repair the device yourself. Refer servicing to qualified personnel.
- Avoid making measurements in wet or damp condicions.
3. Producte acabatview
The HT-Instruments COMBI 420 is a robust and user-friendly multifunction tester. It features a large, clear LCD screen with backlight and a graphical help menu for intuitive operation.

Figure 3.1: HT-Instruments COMBI 420 Multifunction Tester. The device features a large LCD display, navigation buttons, and input terminals for various measurements.
3.1 Característiques clau
- Large, backlit LCD screen with graphical help menu.
- Connectivity for external test probe with remote control (start/stop function).
- Input for external current clamp (e.g., HT96U) from 1 mA to 3000 A.
- Ports for external probes for humidity, temperature, light (lux), and sound level measurements.
- Low-ohm measurement with >200 mA DC (VDE 0413 part 4, EN 61557-4).
- Insulation test with selectable voltages: 50, 100, 250, 500, or 1000 V DC (VDE 0413 part 2, EN 61557-2).
- Comprehensive FI (RCD) test and analysis function (VDE 0413 part 6, EN 61557-6).
- Loop and network impedance measurement (VDE 0413 part 3, EN 61557-3).
- Short-circuit current Ik display (VDE 0413 part 3, EN 61557-3).
- Loop resistance measurement without RCD tripping.
- Rotating field direction measurement (VDE 0413 part 7, EN 61557-7), possible with a single test probe.
- Power measurement: active, reactive, and apparent power, power factor.
- Harmonic analysis of voltage and current up to the 49th harmonic and THD in %.
- Integrated optical USB interface for data transfer.
- Internal memory for 600 measurement values.
- Automatic shutdown feature.
- Integrated rubber protective holster.
- Online connection assistance via display.
3.2 Contingut del paquet
The COMBI 420 package includes:
- HT-Instruments COMBI 420 Multifunction Tester
- A daltview software (incl. USB interface + cable)
- Bossa d'emmagatzematge
- Measurement cable with earthed plug
- 3 safety test leads with banana connectors
- 2 sondes de prova
- 3 pinces de cocodril
- 6 AA batteries (pre-installed or separate)
- Manual d'usuari
- ISO 9000 calibration protocol
4. Configuració
4.1 Instal·lació de la bateria
The COMBI 420 requires 6 AA alkaline batteries. These are typically included with the device. To install or replace batteries:
- Assegureu-vos que el dispositiu estigui apagat.
- Localitzeu el compartiment de la bateria a la part posterior del dispositiu.
- Obriu la coberta del compartiment.
- Introduïu 6 piles AA, observant la polaritat correcta (+/-) tal com s'indica a l'interior del compartiment.
- Tanqueu bé la tapa del compartiment de la bateria.
4.2 Connecting Test Leads and Accessories
Connect the appropriate test leads and accessories to the input terminals on the COMBI 420 based on the measurement you intend to perform. Always ensure connections are secure.
- Safety Test Leads: Use the provided safety test leads with banana connectors for most standard measurements.
- Earthed Plug Cable: For measurements requiring a connection to an earthed socket.
- External Test Probe: Connect to the designated port for remote start/stop functionality.
- External Current Clamp: Connect to the appropriate input for current measurements (e.g., HT96U).
- Sondes externes: Connect humidity, temperature, light, or sound level probes to their respective ports.
5. Instruccions de funcionament
5.1 Engegada/apagada
Premeu el botó PODER button to turn the device on. The device will perform a self-test and display the main menu. To turn off, press and hold the PODER button, or allow the automatic shutdown feature to activate after a period of inactivity.
5.2 Navigation and Display
Use the directional buttons and the ENTRAR button to navigate through the menus and select functions. The large LCD screen displays measurement results, settings, and the graphical help menu. Press ESC/MENU to return to the previous menu or access the main menu. The AJUDA button provides on-screen assistance for current functions.
5.3 Funcions de mesura
The COMBI 420 offers a wide range of measurement capabilities. Always refer to the on-screen help or specific sections of this manual for detailed connection diagrams and procedures for each test.
- Low-Ohm Measurement (Continuity):
Measures resistance with a test current of >200 mA DC, compliant with VDE 0413 part 4 (EN 61557-4). Used to verify the continuity of protective conductors and equipotential bonding.
- Prova d'aïllament:
Performs insulation resistance measurements at 50, 100, 250, 500, or 1000 V DC, compliant with VDE 0413 part 2 (EN 61557-2). Essential for checking the integrity of insulation in electrical systems.
- FI (RCD) Test and Analysis:
Comprehensive testing of Residual Current Devices (RCDs) according to VDE 0413 part 6 (EN 61557-6). Includes trip time, trip current, and contact voltage mesures.
- Loop and Network Impedance Measurement:
Measures loop impedance and network impedance, compliant with VDE 0413 part 3 (EN 61557-3). This is crucial for determining prospective fault current and ensuring proper circuit breaker operation.
- Short-Circuit Current Ik Display:
Displays the calculated prospective short-circuit current (Ik) based on impedance measurements, as per VDE 0413 part 3 (EN 61557-3).
- Loop Resistance without RCD Tripping:
Allows loop resistance measurement in circuits protected by RCDs without causing the RCD to trip, using a low test current.
- Rotating Field Direction Measurement:
Determines the phase sequence (rotating field direction) in three-phase systems, compliant with VDE 0413 part 7 (EN 61557-7). This can be performed even with a single test probe.
- Power Measurement and Harmonic Analysis:
Measures active, reactive, and apparent power, as well as power factor. Performs harmonic analysis of voltage and current up to the 49th harmonic and calculates Total Harmonic Distortion (THD) in percentage.
- External Probe Measurements:
When connected, the device can display readings from external humidity, temperature, light (lux), and sound level probes.
5.4 Emmagatzematge i transferència de dades
The COMBI 420 has an internal memory capable of storing up to 600 measurement values. Use the DESA button to store current measurement results. Data can be transferred to a PC using the integrated optical USB interface and the provided Topview programari.
6. Manteniment
6.1 Neteja
Clean the device regularly with a soft, dry cloth. Do not use abrasive cleaners or solvents. Ensure no moisture enters the device.
6.2 Substitució de la bateria
Replace batteries when the low battery indicator appears on the display. Refer to Section 4.1 for battery installation instructions. Always use new, high-quality AA alkaline batteries.
6.3 Calibració
For continued accuracy and compliance, periodic calibration by an authorized service center is recommended. The device is supplied with an ISO 9000 calibration protocol, indicating its initial calibration status.
7. Solució De Problemes
If you encounter issues with your COMBI 420, try the following basic troubleshooting steps:
- El dispositiu no s'encén: Comproveu la instal·lació de les piles i assegureu-vos que no estiguin esgotades. Substituïu-les si cal.
- Incorrect or erratic readings: Verify that test leads are correctly and securely connected. Ensure the correct measurement function is selected. Check for damaged test leads or probes.
- Problemes de visualització: If the display is dim, check battery level. If the display is frozen, try restarting the device.
- Problemes de transferència de dades: Ensure the USB cable is properly connected and the Topview software is correctly installed and running on your PC.
For more complex issues, utilize the device's built-in graphical help menu or contact HT-Instruments technical support.
8. Especificacions
| Característica | Especificació |
|---|---|
| Número de model | COMBI 420 |
| Fabricant | HT-Instruments |
| Dimensions del producte (L x A x A) | 24 x 17 x 8 cm (aprox. 9.45 x 6.69 x 3.15 polzades) |
| Pes | 3 kg (aprox. 6.6 lliures) |
| Font d'alimentació | Battery-Powered (6 AA batteries required, included) |
| Compliment de seguretat | IEC-1010-1, CAT III 415 V |
| Estàndards de mesura | VDE (EN61557) parts 2, 3, 4, 6, 7 |
| Memòria interna | 600 measurement values |
| Interfície | USB òptic |
| Components inclosos | A daltview software, USB cable, storage bag, measurement cable with earthed plug, 3 safety test leads, 2 test probes, 3 crocodile clips, batteries, user manual, ISO 9000 calibration protocol |
9. Garantia i Suport
HT-Instruments products are manufactured to high quality standards. For specific warranty information, please refer to the documentation included with your purchase or visit the official HT-Instruments website. For technical support, service, or inquiries regarding calibration, please contact your local HT-Instruments distributor or customer service department.
