I. Introduction
HZJD-470A digital grounding resistance tester is designed and manufactured according to the new lightning protection grounding resistance detection standard. The short-circuit test current can reach 20mA. The precision 3-wire method or simple 2-wire method can be used to measure the grounding resistance, and FFT (fast Fourier transform) is introduced. Technology, using digital filtering algorithm, has unique anti-interference ability and environmental adaptability, and has strong consistency in repeated tests. It is widely used in grounding resistance and grounding voltage measurement of electric power, telecommunications, meteorology, oil field, construction, lightning protection and industrial electrical equipment, etc.
The instrument has a unique line resistance calibration function, which is more accurate in the measurement of low-value grounding resistance on site, and can avoid errors caused by changes in line resistance caused by long-term use of the test line; it can avoid errors caused by the test line not being fully inserted into the instrument interface or poor contact. Error; it can avoid the error caused by the user changing or lengthening the test line.
The instrument is composed of host, test line, auxiliary ground rod, data software, communication line and so on. The host adopts an integrated hand-held design, which has low density, light weight, superior strength, rigidity, hardness, wear resistance, heat resistance and insulation performance, ensuring high precision, high stability and high reliability of various environmental tests . The main unit has a large LCD display with backlight and bar graph instructions, which are clear at a glance, and can store 300 sets of data. Through the data software, functions such as reading, consulting, saving, reporting, and printing of historical data can be realized.
II. Technical Specifications
Function | Ground resistance, ground voltage, low value resistance measurement |
Power supply | DC 14.8V 2600mAh rechargeable lithium battery , the battery is fully Charged at about 16.8V |
Backlight | Controllable white screen backlight, suitable for use in dark places |
Measurement method | Precise three-wire method and simple two-wire method to measure grounding resistance |
Measurement methods | Earth resistance measurement: Rated current changing pole method |
Voltage to ground: average value rectification (between PE interfaces) | |
Range | Ground resistance: 0.000Ω~200KΩ |
Ground voltage: AC 0.000V~600V (50Hz/60Hz) | |
Resolution | 0.001Ω ; 0.005V |
Precision | Ground resistance: ±2%rdg±5dgt Note: 1. Auxiliary connection Rc: 500Ω~1000Ω error≤±5dgt 2. Auxiliary connection Rp: 500Ω~10KΩ error≤±3dgt 3. When the interference voltage is 5V, the additional error is ≤±5%rdg± 5dgt |
Ground voltage: ±2%rdg±3dgt (50Hz/60Hz) | |
Test voltage waveform | Sine wave |
Test frequency | 700Hz |
Test current | 0.000Ω~100.0Ω range: about 20mA constant current 100Ω~200.0KΩ range: about 0.1mA constant current |
Open circuit test voltage | AC 40Vmax |
Display mode | Large LCD display |
Measurement indication | LED flashing indication during measurement, LCD countdown display |
LCD size | 128mm×75mm |
LCD display field | 124mm×67mm |
Product Size | Meter size: length, width and height 258mm×21 5 mm×83mm |
Package size: 27 0mm *16 0mm *25 0mm | |
Test line | 3 pieces: red 15m, yellow 10m, green 5m each |
Simple test line | 2 pieces: 1 piece of red 1.6m and 1 piece of green 1.6m |
Auxiliary ground rod | 2 pieces: φ 10mm× 20 0mm |
Measure time | Ground voltage: about 2 times/second; ground resistance: about 5 seconds/time |
Measurement times | More than 5000 times (short circuit test, test once, stop for 30 seconds and test again) |
Line voltage | Measured below AC 600V |
Communication Interface | With USB interface |
Communication line | 1 USB communication line |
Data retention | HOLD ” symbol indicates when data is held |
Data storage | 300 groups, " HOLD " storage indication, " FULL " symbol is displayed when the storage is full |
Data review | READ " symbol indicates when looking up the data |
Overflow display | OL " symbol indication when over-range overflow |
Interference test | Automatic identification of interference signals; when measuring, the voltage of interference signals between PEs is higher than 5 volts, and the LCD displays NOISE symbols |
Alarm function | When the measured value exceeds the alarm setting value, "beep-beep-beep--" alarm prompt |
Battery voltage | When the battery power is lower than 25%, the low battery voltage symbol is always displayed, reminding that it needs to be charged in time; when the battery power is lower than 10%, the LCD screen continues to flash, and the instrument will automatically shut down after about 5 seconds |
Automatic shut-down | When there is no operation, it will automatically shut down after about 15 minutes |
Power consumption | Backlight: 25mA Max (power consumption of backlight alone) |
Standby: 35mA Max (backlight off after power on) | |
Measurement: 150mA Max (backlight off) | |
Quality | Meter: 1.55kg (including battery) |
Total mass: 3.45kg (including packaging) | |
Working temperature and humidity | -10℃~40℃; below 80%rh |
Storage temperature and humidity | -20℃~60℃; below 70%rh |
Overvoltage protection | AC 75V between CE ports AC 600V between PE ports AC 600V between PC ports |
Insulation resistance | >500MΩ between test line and case |
Withstand voltage | AC10.0kV 50Hz between the test line and the case for 1min |
Electromagnetic properties | IEC61326(EMC) |
Suitable for safety regulations | IEC61010-1 (CAT Ⅲ 300V, CAT IV 150V, pollution degree 2); IEC61010-031; IEC61557-1 (grounding resistance); JJG 366-2004 (grounding resistance meter). |