Introduction
The CEM DT-6650 is a rugged Multifunction Installation Tester equipped with a 3.5-inch TFT color LCD display. It is designed to provide comprehensive testing capabilities for insulation resistance, earth resistance, loop impedance, voltage, RCD (Residual Current Device), PFG (Prospective Fault Current), and PSC (Prospective Short Circuit Current). This device features a sophisticated software system to ensure the safety and correct installation of electrical systems in domestic, commercial, and industrial environments. The 6650 series offers fast sampling, a dual display, clear symbols, and an exceptionally wide viewing angle for easy and safe readings.
Key Features
- 3.5-inch TFT color LCD display with 320x240 pixels resolution.
- Fast high current loop test capability.
- Variable RCD current mode for customized settings.
- PASS/FAIL indication for RCD tests.
- Selectable voltage measurement between L-N, L-PE, and N-PE.
- Support for SD memory, USB, and wireless interface for data transfer.
- Internal Memory for data storage.
- Safe Earth Volt Touchpad detects raised earth voltages >50 V, indicating potential dangerous situations.
- Slim probes designed with integrated test buttons.
- Automatic compensation for test leads and mains cords for reliable and accurate measurements.
Package Contents
The standard package includes the following items:
- DT-6650 Multifunction Installation Tester
- Test leads (set of red, green, blue, and black leads with various connectors)
- 8 x 1.5V “AAA” batteries
- USB cable
- Software CD
- Gift box with carrying case
Optional accessories, such as additional resistance test kits (M-530, TL-533, TL-531), may be available separately.
Setup
-
Battery Installation: Open the battery compartment on the back of the device. Insert 8 x 1.5V “AAA” batteries, ensuring correct polarity. Close the compartment securely.
-
Connecting Test Leads: Connect the appropriate test leads to the input terminals on the DT-6650. Ensure a firm connection for accurate readings and safety. For specific tests like earth resistance, use the provided ground stakes and leads as shown in Figure 4.
Figure 4: Earth Resistance Measurement Setup. -
Power On: Turn the rotary dial to the desired measurement function to power on the device. The 3.5-inch TFT color LCD display will illuminate.
Operation
The DT-6650 features a rotary dial for selecting primary test functions and function buttons (F1-F4) for navigating sub-menus and settings. The large color LCD provides clear readings and graphical representations.
General Testing Procedure:
- Select Function: Rotate the main dial to the desired test function (e.g., INSULATION, LOOP, RCD, LOW OHM, VOLTAGE).
- Connect Leads: Connect the test leads to the circuit or component under test according to the specific test requirements. Ensure all connections are secure and safe.
- Configure Settings: Use the F1-F4 function buttons to adjust test parameters (e.g., test voltage for insulation, RCD current for RCD tests) as needed. The display will guide you through available options.
- Initiate Test: Press the 'TEST' button to begin the measurement.
- Read Results: Observe the results on the TFT color LCD display. For RCD tests, a PASS/FAIL indication will be provided.
Specific Test Functions:
-
Insulation Resistance: Select the INSULATION function. Choose the desired test voltage (125V, 250V, 500V, 1000V). Connect leads to the circuit and press TEST. The device measures resistance up to 4000MΩ.
-
Loop Impedance (L-PE Hi-Amp / No Trip): Select the LOOP function. The device supports fast high current loop tests and no-trip tests. Connect leads to L-PE and press TEST. The display will show impedance and other relevant parameters.
-
RCD Testing: Select the RCD function. Configure the RCD type and current multiplier (x1/2, x1, x2, x5) using the function buttons. Connect leads to the RCD circuit and press TEST. The device will indicate PASS/FAIL and trip time. See Figure 6 for an example.
Figure 6: RCD Test Results Display. -
Low OHM / Continuity: Select the LOW OHM function. Connect leads to the component. The device measures resistance and provides a continuity beeper for quick checks.
-
Voltage Measurement: Select the VOLTAGE function. The device can measure voltage between L-N, L-PE, and N-PE. Connect leads to the desired points. The Safe Earth Volt Touchpad can detect hazardous voltages >50V.
Figure 7: Testing an Electrical Panel.
The device supports data logging to SD memory and transfer via USB or wireless interface for further analysis.
Maintenance
- Cleaning: Wipe the device with a soft, damp cloth. Do not use abrasive cleaners or solvents. Ensure the device is dry before storage or next use.
- Battery Replacement: Replace batteries promptly when the low battery indicator appears to ensure accurate measurements. Always use 8 x 1.5V “AAA” batteries.
- Storage: Store the tester in its carrying case in a cool, dry place away from direct sunlight and extreme temperatures. Remove batteries if storing for extended periods to prevent leakage.
- Test Leads: Regularly inspect test leads for any signs of damage, such as cuts, cracks, or frayed insulation. Replace damaged leads immediately to ensure safety and accuracy.
Troubleshooting
- Device does not power on: Check if batteries are correctly installed and have sufficient charge. Replace batteries if necessary.
- Inaccurate readings: Ensure test leads are properly connected and undamaged. Verify that the correct test function and parameters are selected for the measurement. Clean the test points if they are dirty.
- Display issues: If the display is dim or flickering, check battery levels. If the issue persists, contact customer support.
- No RCD trip: Ensure the RCD is functional and correctly wired. Verify the test current and multiplier settings on the DT-6650.
Specifications
Dimensions: 220mm (H) x 96.5mm (W) x 60.5mm (D)
Weight: 631g
Insulation
| Terminal Voltage | Range | Max Resolution | Accuracy | Test Current | Short circuit current |
|---|---|---|---|---|---|
| 125V (0% ~ +10) | 0.125~4000MΩ | 0.001MΩ | ±(2%+10) | 1mA@load 125kΩ | ≤1mA |
| 250V (0% ~ +10) | 0.250~4000MΩ | 0.001MΩ | ±(2%+10) | 1mA@load 250kΩ | ≤1mA |
| 500V (0% ~ +10) | 0.500~4000MΩ | 0.001MΩ | ±(2%+10) | 1mA@load 500kΩ | ≤1mA |
| 1000V (0% ~ +10) | 1.000~4000MΩ | 0.001MΩ | ±(3%+10) | 1mA@load 1MΩ | ≤1mA |
Low OHM
| Range | Resolution | Accuracy | Max. open Circuit Voltage | Overload Protection |
|---|---|---|---|---|
| 4.000Ω | 0.001Ω | ±(1.5%+30) | 5.8V | 250Vrms |
| 40.00Ω | 0.01Ω | ±(1.5%+3) | 5.8V | 250Vrms |
| 400.0Ω | 0.1Ω | ±(1.5%+3) | 5.8V | 250Vrms |
Continuity Beeper
| Range | Resolution | Operation Resistance | Max. open Circuit Voltage | Overload Protection |
|---|---|---|---|---|
| Continuity | 0.01Ω | Resistance≤35Ω | 5.0V±1VDC | 250Vrms |
Short circuit current: ≥200mA
LOOP Resistance
L-PE (Hi-Amp)
| Range (Ω) | Max. Resolution (Ω) | Accuracy |
|---|---|---|
| 0.00~999 | 0.01 | ±(4% of reading+6 digits) |
L-PE (No Trip): Measuring Current:15mA / Range of the Voltage Used: 195V a.c.~260V a.c.(56,60Hz)
| Range (Ω) | Resolution (Ω) | Accuracy |
|---|---|---|
| 0.00~999 | 0.01 | ±(5% of reading+6 digits) |
L-N: Measuring Current:2.0A / Range of the Voltage Used:195V a.c.~260V a.c.(56,60Hz)
| Range (Ω) | Max. Resolution (Ω) | Accuracy |
|---|---|---|
| 0.00~999 | 0.01 | ±(4% of reading+4 digits) |
RCD Testing
| Test current | Accuracy |
|---|---|
| x1/2, x1, x2, x5 | 1.5%~ -9% |
Voltage and Frequency
| Measurement Range (V)/ AC-DC | Resolution | Accuracy |
|---|---|---|
| 80-500V/(45-400Hz) | 1V | ±(2% of reading+2 digits) |
User Tips
- Always ensure the device is set to the correct measurement function before connecting to a circuit to prevent damage to the tester or the circuit.
- For insulation tests, ensure the circuit is de-energized and safely isolated before proceeding.
- Utilize the data logging features (SD card, USB, wireless) to record measurements for compliance documentation or trend analysis.
- The Safe Earth Volt Touchpad is a critical safety feature; always be aware of its indications when working with potentially live circuits.
Warranty and Support
For warranty information, technical support, or service inquiries, please refer to the documentation provided with your purchase or contact the manufacturer directly. Keep your proof of purchase for warranty claims.
