AEMC 4500 20kohm 4 Point Ground Resistance Tester
Description
The Digital Ground Resistance Tester Model 4500 is designed for measuring very low resistance on large grounding systems, such as ground grids and ground mats. It rejects high levels of interference voltages at DC or 60Hz and its harmonics, and can be used under difficult conditions such as high stray currents or excessive auxiliary electrode resistance without substantially affecting accuracy.
Features
- Measures soil resistivity (4-Point)
- Measure ground resistance (2- and 3-Point) Fall-of-Potential Method
- Step voltage tests and touch potential measurements
- Selectable: three test currents and five resistance ranges
- Measures very low resistance on large grounding systems and grids
- High test current also enables geological surveys
- Large easy-to-read LCD
- Display includes indicators for excess stray current and voltage, high auxiliary rod resistance and fault connection
- Battery (rechargeable) powered or external 12VDC
- Rugged dustproof and rainproof field case
- Can be used for continuity tests on bonding
- Includes power cord, 12V NiCD battery, hex key, spare fuse and user manual
AEMC 4500 Applications
- Three-point measurement of large grounding grids, counterpoises, ground mats and grounded equipment.
- Soil resistivity tests (4-Point measurement), commonly performed by utilities at proposed construction sites. Using soil resistivity analysis, the size and complexity of grounding system construction can be evaluated.
- The Ground Resistance Tester Model 4500 will measure the resistivity of epoxies, cement, ground enhancement materials and many other substances.
- Step or touch potential levels under true fault conditions can be deter- mined by using the Model 4500 to inject a simulated low-level fault into an electrical system. When used in this fashion, the Model 4500 will display readings in volts per fault ampere.
- Two-point tests for continuity tests on bonding or on pre-established grounds.
Specifications
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ELECTRICAL |
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Ranges |
2Ω |
20Ω |
200Ω |
2000Ω |
20kΩ |
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Resolution |
1mΩ |
10mΩ |
0.1Ω |
1Ω |
10Ω |
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Resistance Measurement Frequency |
128Hz square wave |
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Test Current |
2mA, 10mA, 50mA |
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Accuracy |
±2% of Reading ± 1ct from 10% to 100% of range |
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Auxiliary Electrode Resistance |
Ry: 50kΩ on 20Ω, 200Ω, 2000Ω & 20kΩ ranges; 5kΩ on 2Ω range Rz: 2mA range: 15kΩ; 10mA range: 3000Ω; 50mA range: 400Ω |
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Interference |
The unit is designed to reject high levels of interference voltages at DC, or 50/60 Hz and their harmonics |
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Noise Influence on Accuracy |
0.5% of range (max) to 20V peak |
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Power Source |
Built-in rechargeable 12V, one Ah NiCD battery, or external 12 VDC; low battery indication. Battery can be recharged with built-in dual voltage charging unit: 94 to 127V or 187 to 253V (47 to 450Hz) |
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Charging Time |
14 hours typical |
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Charging Supply Voltage |
Internally selectable 110/220V, 45 to 450Hz |
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Battery Life |
Four hrs on 50mA test current (800 15 sec measurements), Seven hrs on 2mA and 10mA test currents (1500 15 sec. measurements) |
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Fuse Protection |
500Vrms measurement circuit |
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MECHANICAL |
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Display |
7-segment LCD, 0.71″ (18mm) high (31/2 digit); 2000-count |
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Connection |
Terminals accept spade lugs with min. gap of 6mm or standard 4mm banana jacks |
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Operating Temperature |
14° to 122°F (-10° to 50°C) |
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Dimensions |
15.75 x 10.2 x 9.8″ (400 x 260 x 250mm) |
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Weight |
14 lbs (6.5kg) approximate |
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Case |
Heavy-duty plastic, with detachable cover and carrying handle |
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Colors |
Case: safety yellow; Front panel: brown |
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Dielectric Test |
2000Vrms, 50/60Hz between 4 interconnected measuring terminals and any external metal ground; 2000Vrms, 50/60Hz between line input and measuring terminals on front panel |
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Environmental |
O-ring sealed faceplate against water and dust; sealed cover when closed; IEC529, DIN 0470-T1 |
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SAFETY |
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Rating |
EN 61010 |
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Double Insulation |
Yes |
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Impact Resistance |
Shock and vibration according to MIL-T-28800D class 3 |
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CE Mark |
Yes |
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