Aemc instruments 3730, 3710 User Manual

Clamp-On

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Model 3710

GROUN D TES TER

AEMC

I NS T R U M E NT S

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Model 3730

GROUN D TES TER

AEMC

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Ground Resistance Testers
Models 3710 and 3730

USER MANUAL

Owner’s Record

The serial number for the Model 3710 or Model 3730 is located inside
the battery compartment of the instrument. Please record this number
and purchase date for your records.

CLAMP-ON GROUND RESISTANCE TESTER MODEL 3710
CATALOG #1221.01
SERIAL #:
PURCHASE DATE:
DISTRIBUTOR:

CLAMP-ON GROUND RESISTANCE TESTER MODEL 3730
CATALOG #1221.02
SERIAL #:
PURCHASE DATE:
DISTRIBUTOR:

99-MAN-100061
5th Revision
Printed 03/98

AEMC®Instruments
by Chauvin Arnoux, Inc.

Table of Contents

Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Receiving Your Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Government Orders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Mechanical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Safety Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Model 3710 Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Model 3730 Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Digital Display Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Additional Features of the Model 3730 . . . . . . . . . . . . . . . . . . .12

Function Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Programming the Alarm Setpoint . . . . . . . . . . . . . . . . . . . . . . .17

Changing the Alarm Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Memory Recall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Clear Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Function Access Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Programming Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Field Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Operating Reference Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Calibration Check Loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Commonly Asked Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Battery Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Table of Contents (cont.)

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Repair and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Technical and Sales Assistance . . . . . . . . . . . . . . . . . . . . . . . . . .36

Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . .Inside back cover

Warning

These safety warnings are provided to ensure the safety of per­sonnel and the proper operation of the instrument.

• The instrument must not be operated beyond its specified oper­ating range.

• Safety is the responsibility of the operator.

• All metal objects or wires connected to the electrical system
should be assumed to be lethal until tested. Grounding systems
are no exception.

• Use extreme caution when using the instrument around ener­gized electrical equipment.

• Never attempt to use the instrument to twist or pry the ground
electrode or ground wire away from the equipment being
grounded.

• Open and close the clamp-on jaws slowly ensuring proper
alignment.

• AEMC®Instruments considers the use of rubber gloves to be an
excellent safety practice even if the equipment is properly oper­ated and correctly grounded.

Ground Resistance Tester Models 3710/3730

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Receiving Your Shipment

Upon receiving your shipment, be sure that the contents are consistent
with the packing list. Notify your distributor of any missing items. If the
equipment appears to be damaged, file a claim immediately with the
carrier and notify your distributor at once, giving a detailed description
of any damage. Save the damaged packing container to substantiate
your claim.

Packaging

The Clamp-On Ground Resistance Testers Model 3710 (Cat. #1221.01)
and Model 3730 (Cat. #1221.02) are shipped with a hard carrying case,
one 9 V battery (not installed), an instruction manual with warranty
registration and a calibration loop. The manual, warranty card, and cal­ibration loop are located behind the “egg crate” foam on the inside of the
carrying case cover.

Government Orders

The Clamp-On Ground Resistance Tester Model 3710 (Cat. #1221.01)
has been issued a National Stock Number. Orders for the Model 3710
should reference NSN 6625-01-377-8030.

Accessories

One multiple calibration loop, Cat. #1223.01

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Ground Resistance Tester Models 3710/3730

Description

Outline

The ground resistance tester Models 3710 and 3730 measure ground rod
and small grid resistance through any season, without the use of auxiliary
ground rods. Clamp-on ground resistance testers are used in multi­grounded systems without disconnecting the ground under test. The
Models 3710 and 3730 simply clamp around the ground conductor or rod
and measure the resistance to ground. By performing measurements on
intact ground systems, the user also verifies the quality of the grounding
connections and bonds. Resistance and continuity of grounding loops
around pads and buildings may also be measured.

Both models include a current measurement function. The probe’s high
sensitivity enables measurement of leakage current flowing to ground or
circulating in ground loops down to 1 mA and neutral currents to 30 A
rms. This feature provides additional information which is becoming vital
as distribution ground networks carry higher levels of noise and
harmonics which affect power quality.

Both models offer battery life information at power-up and Auto-Off
for power management. Additional features are also displayed on the
large LCD to ensure precise measurements. The Buzzer and Auto-Off
features may be disabled from the push-buttons at any time.

The Model 3730 offers an Alarm function and a Memory (logging) func­tion. In the Alarm mode, the probe will audibly and visually indicate if the
reading is beyond an input set point. The user may also have the Alarm
initiated above or below the set point. This Alarm feature permits quick
field checks where only “pass” or “fail” readings will suffice.

The Memory function logs up to 99 measurements (Ohms or Amperes).
This enables the user to conduct field surveys, and to retrieve and
analyze the readings at a later time. The alarm settings and stored
memory information are saved when the ground tester is turned off.

Product Construction

The Models 3710 and 3730 body cases are built of Lexan®for rugged
use. The probe heads are encapsulated in a double-walled Lexan®shell

Ground Resistance Tester Models 3710/3730

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for extra strength and are reinforced at the body interfaces for enhanced
field reliability. Overall construction and mechanical design ratings such
as drop test, shock and vibration, weatherproofing against water
projections or dust, meet or exceed IEC (International Electrotechnical
Commission) standards. The products have also been designed to
meet IEC 1010, UL 1244, CSA and GS safety approvals .

Jaw Design

The probe head, or jaw, is a key component in the measurement and
overall product performance. Considerable research and development
were dedicated to ensuring its performance, reliability and versatility.

The large jaw has an inner opening diameter of 1.25" (32 mm) - double
its predecessor’s diameter - while retaining the same overall jaw
thickness, permitting use on tight ground conductors on poles and in
manholes. The large opening accommodates not only ground rods, but
larger ground conductors (up to 1000 MCM) typically found in telecom­munication or railroad applications.

The inner jaw is composed of two independent and individually shielded
magnetic cores permitting the injection of a test signal and accurate
return signal measurement without noise interference or cross talk
common to separate probe instruments.

Thorough mechanical design, including small winglets, ensures repetitive
jaw alignment for accuracy and prevents undesirable insertions into the
jaw spring assembly.

Body Design

The ergonomic body design permits one-handed operation. The guard
provides additional strength, and prevents the hand from slipping or
coming into contact with conductors under test. The Lexan®body con­struction provides strength. The LCD lens cover may be easily replaced
if scratched. The sealed push-buttons directly access all test functions
and are easily operated even with gloved hands.

Lexan®is a registered trademark of General Electric Corporation.

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Ground Resistance Tester Models 3710/3730

Electrical Specifications

Ground Resistance

Measurement Range

Autoranging

1.0 to 1200 Ω

Range

1.0 to 50.0 Ω

50.0 to 100.0 Ω
100 to 200 Ω
200 to 400 Ω
400 to 600 Ω

600 to 1200 Ω

Ground or Leakage Current

Autoranging

1 mA to 30.00 A rms

* Reference conditions: 23°C ± 3K, 50% RH ± 10%, battery at 8 V ± 0.2V,
external magnetic field < 40 A/m, external electrical field < 1 V/m, conductor
centered, loop resistance noninductive. Accuracy % of reading.

1 to 300 mA

0.300 A to 3.000 A

3.00 A to 30.00 A

Resistance Measurement Frequency: 1689 Hz
Resistance Overload: OL displayed above 1200 Ω
Current Measurement Frequency: 47 to 800 Hz
Current Overload: OL displayed above 30 A rms

Resolution

0.1 Ω

0.5 Ω
1 Ω
5 Ω

10 Ω
50 Ω

1 mA

0.001 A

0.01 A

Accuracy*

± (1.5% + 0.1 Ω)
± (2.0% + 0.5 Ω)

± (3.0% + 1 Ω)
± (6.0% + 5 Ω)

± (10% + 10 Ω)

Approx. 25%

± (2.5% + 2 mA)
± (2.5% + 2 mA)

± (2.5% + 20 mA)

MECHANICAL SPECIFICATIONS
Dimensions: 9.25 x 3.94 x 2.17" (235 x 100 x 55 mm)
Weight: 2.2 lbs. (1 kg)
Case Material: Lexan®920A (UL94V2)

Ground Resistance Tester Models 3710/3730

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Jaw Cover Material:

Lexan®500R with 10% fiberglass charge (UL94V0)

LCD Cover Material: Lexan®920A (UL94V1)
Color: Gray body, red jaws
Jaw Window Diameter: 1.25” (32 mm)
Jaw Opening: 1.38” (35 mm)
Operating Temperature: -10 ° to 55 °C
Operating Humidity: 0 to 90% RH @ -10 ° to 40 °C, 75% RH @ 55 °C
Storage Temperature: -40 ° to 70 °C
Power Supply: 9 V alkaline (IEC 6LF22 or NEDA 1604A)
Battery Life:

typical: 8 hours or approximately 1000 measurements of 30 seconds

LCD: 3-3/4 digit, 1.73 x 1.10” (44 x 28 mm)
US Design Patent: #362,639

SAFETY SPECIFICATIONS

UL, CSA approvals pending
IEC 1010-1 Double Insulation

Environmental: IP30, IEC 359 Group III
Vibration Test: IEC 68-2-6
Shock Test: IEC 68-2-27
Drop Test (1m): IEC 68-2-32
Dielectric Test: 2500 V AC
Working Voltage: 150 V, Cat. III - Pollution Degree 2

300 V, Cat. III - Pollution Degree 1

Max A Overload: 100 A continuous, 200 A (< 5s) 50/60 Hz
OL displayed above 30 A rms

Calibration Cycle: Calibration once a year is recommended

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Ground Resistance Tester Models 3710/3730

Model 3710 Controls

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MEM

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Model 3710

GROUN D TES TER

AEMC

IN S T R U ME N T S

A Ω

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OFF

1

2

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56

1. Head Assembly: Consists of
two individually shielded
magnetic cores

2. Hold: Freezes last measured
value on the display

3. Display: 3000 count LCD,

Ground Resistance Tester Models 3710/3730

function indicators

4. ON/OFF: Power ON or OFF,
activates display self-test at
power-up

5. Ω: Resistance measurement

6. A: Current measurement

7. Lever: Opens or closes jaws

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Model 3730 Controls

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Model 3730

GROUN D TES TER

AEMC

IN S T R UM E N T S

MEM AL A Ω

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OFF

1

2

3

49

7

568

1. Head Assembly: Consists
of two individually shielded
magnetic cores

2. Hold: Freezes last mea­sured value on the display

3. Display: 3000 count LCD,
function indicators

4. ON/OFF: Power ON or
OFF, activates display self
test at power-up

5. Ω: Resistance Measurement
Increment the Alarm set-

point, increment Memory
position in program mode

6. A: Current Measurement
Decrement the Alarm

setpoint, decrement the
Memory in program mode

7. Lever: Opens or closes jaws

8. AL: Activates/deactivates
the Alarm function, access
the value of the Alarm
setpoint in program mode

9. MEM: Stores the reading into memory, reads Memory Recall (MR)
values and clears the memory in recall mode

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Ground Resistance Tester Models 3710/3730