Atec AEMC-4500 User Manual

Model 4500 (pdf) Rev. 04 11/04

Technical Assistance [phone] www.aemc.com 1 of 5

Digital Ground Resistance Tester
Model 4500

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.

The Model 4500 has three selectable
test current ranges (2, 10, 50mA) and
five selectable resistance testing
ranges (2Ω, 20Ω, 200Ω, 2000Ω and
20kΩ). It is capable of direct readings
with a resolution as low as 1mΩ.

With such a wide resistance capability,
the Model 4500 is capable of measuring
the resistivities of soil and other materials
from below 10mΩ-cm to over 1MΩ-cm.

Readings are displayed on a large
(0.71"), 3

1

/2digit LCD. The LCD blinks
and a pointer on the display lights to
warn of excess stray current or auxiliary
electrode resistance, or when there is a
lack of continuity between leads and
electrodes. Abeeper will notify the user
if voltage greater than 20 volts peak is
present between terminals X (C1) and
Y (P2) or X and Z (C2) when the
ground leads are connected.

The instrument is fuse protected up
to 500A

AC to protect the instrument

against voltage into the test leads.

Power is supplied by a rechargeable
12V battery; the tester may also be
operated from an external 12V

DC supply.

Abattery charge indicator and low
battery indicator appear on the LCD
and a dual-voltage charging unit is built
into the instrument.

The heavy-duty, safety yellow case
is dust and water resistant to ensure
reliable field use. The cover may be
detached while the meter is in use,
if desired. Optional test kits are
available for ground resistance and
soil resistivity tests.

Model 4500 (pdf) Rev. 04 11/04

Technical Assistance [phone] www.aemc.com 2 of 5

Specifications

ELECTRICAL

Ranges 2Ω 20Ω 200Ω 2000Ω 20kΩ
Resolution 1mΩ 10mΩ 0.1Ω 1Ω 10Ω
Resistance Measurement

Frequency

128Hz square wave

Test Current 2mA, 10mA, 50mA
Accuracy ±2% of Reading ± 1ct from 10% to 100% of range
Auxiliary Electrode Ry: 50kΩ on 20Ω, 200Ω, 2000Ω & 20kΩ ranges; 5kΩ on 2Ω range

Resistance Rz: 2mA range: 15kΩ; 10mA range: 3000Ω; 50mA range: 400Ω
Interference The unit is designed to reject high levels of interference voltages

at DC, or 50/60 Hz and their harmonics

Noise Influence

0.5% of range (max) to 20V peak

on Accuracy
Power Source Built-in rechargeable 12V, one Ah NiCD battery, or external 12 V

DC; low battery indication.

Battery can be recharged with built-in dual voltage charging unit:

94 to 127V or 187 to 253V (47 to 450Hz)

Charging Time 14 hours typical
Charging Supply Voltage Internally selectable 110/220V, 45 to 450Hz
Battery Life Four hrs on 50mA test current (800 15 sec measurements),

Seven hrs on 2mA and 10mA test currents (1500 15 sec. measurements)

Fuse Protection 500Vrms measurement circuit

MECHANICAL

Display 7-segment LCD, 0.71" (18mm) high (31/2digit); 2000-count
Connection Terminals accept spade lugs with min. gap of 6mm or

standard 4mm banana jacks

Operating Temperature 14° to 122°F (-10° to 50°C)
Dimensions 15.75 x 10.2 x 9.8" (400 x 260 x 250mm)
Weight 14 lbs (6.5kg) approximate
Case Heavy-duty plastic, with detachable cover and carrying handle
Colors Case: safety yellow; Front panel: brown
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

Environmental O-ring sealed faceplate against water and dust; sealed cover

when closed; IEC529, DIN 0470-T1

SAFETY

Rating EN 61010
Double Insulation Yes
Impact Resistance Shock and vibration according to MIL-T-28800D class 3
CE Mark Yes

Features

• Measures soil resistivvity (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 12V

DC

• 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

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 deter­mined 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.