ERICO EST401 ERITECH Clamp-on Ground Resistance Tester User Manual

Instruction

Manual

ERITECH®Clamp-On

Ground Resistance

Tester Model EST401

EST401

GROUND TESTER

Limited Warranty

The Model EST401 is warranted to the owner for a period of one year from the date of
original purchase against defects in manufacture. This limited warranty is given by ERICO

®

,
Inc., not by the distributor from whom it was purchased. This warranty is void if the unit has
been tampered with, abused or if the defect is related to service performed without ERICO,
Inc. authorization.

What ERICO, Inc. will do:

If a malfunction occurs within the one-year period, you may return the instrument to us for
repair, provided we have your proof of purchase. ERICO, Inc. will, at its option, repair or
replace the faulty material.

Warranty Repairs

What you must do to return an Instrument for Warranty Repair:

First, request a Return Material Authorization Number (RMA#) by phone or by fax from
our Service Department (see address below), then return the instrument along with the
RMA Form. Please write the RMA# on the outside of the shipping container. Return the
instrument, postage or shipment pre-paid to:

ERICO, Inc.
34600 Solon Road
Solon, Ohio 44139
Tel: [phone] or [phone]
Fax: [phone] or [phone]

Caution: To protect yourself against in-transit loss, we recommend you insure your
returned material.

NOTE: All customers must obtain an RMA# before returning any instrument.

WARNING
ERICO products shall be installed and used only as indicated in ERICO’s product instruction sheets and training materials. Instruction sheets
are available at www.erico.com and from your ERICO customer service representative. Improper installation, misuse, misapplication or other
failure to completely follow ERICO’s instructions and warnings may cause product malfunction, property damage, serious bodily injury and
death.

WARRANTY
ERICO products are warranted to be free from defects in material and workmanship at the time of shipment. NO OTHER WARRANTY,
WHETHER EXPRESS OR IMPLIED (INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE), SHALL
EXIST IN CONNECTION WITH THE SALE OR USE OF ANY ERICO PRODUCTS. Claims for errors, shortages, defects or nonconformities
ascertainable upon inspection must be made in writing within 5 days after Buyer's receipt of products. All other claims must be made in
writing to ERICO within 6 months from the date of shipment or transport. Products claimed to be nonconforming or defective must, upon
ERICO's prior written approval in accordance with its standard terms and procedures governing returns, promptly be returned to ERICO for
inspection. Claims not made as provided above and within the applicable time period will be barred. ERICO shall in no event be responsible
if the products have not been stored or used in accordance with its specifications and recommended procedures. ERICO will, at its option,
either repair or replace nonconforming or defective products for which it is responsible or return the purchase price to the Buyer. THE
FOREGOING STATES BUYER’S EXCLUSIVE REMEDY FOR ANY BREACH OF ERICO WARRANTY AND FOR ANY CLAIM, WHETHER SOUNDING
IN CONTRACT, TORT OR NEGLIGENCE, FOR LOSS OR INJURY CAUSED BY THE SALE OR USE OF ANY PRODUCT.

LIMITATION OF LIABILITY
ERICO excludes all liability except such liability that is directly attributable to the willful or gross negligence of ERICO's employees. Should
ERICO be held liable its liability shall in no event exceed the total purchase price under the contract. ERICO SHALL IN NO EVENT BE
RESPONSIBLE FOR ANY LOSS OF BUSINESS OR PROFITS, DOWNTIME OR DELAY, LABOR, REPAIR OR MATERIAL COSTS OR ANY SIMILAR
OR DISSIMILAR CONSEQUENTIAL LOSS OR DAMAGE INCURRED BY BUYER.

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Table Of Contents

Limited Warranty.......................................................................................................................

Warranty Repairs .......................................................................................................................

International Electrical Symbols................................................................................................2

Receiving Your Shipment .........................................................................................................3

Packaging................................................................................................................................3

Important Information - Proper Operation ...............................................................................3

Description ..............................................................................................................................4

Product Construction.........................................................................................................4

Jaw Design........................................................................................................................4

Body Design ......................................................................................................................4

Electrical Specifications ............................................................................................................5

Ground Resistance.............................................................................................................5

Ground or Leakage Current...............................................................................................5

Mechanical Specifications ........................................................................................................6

Safety Specifications ................................................................................................................6

EST401 Controls......................................................................................................................7

Digital Display Features............................................................................................................8

Function Controls ....................................................................................................................9

On/Off...............................................................................................................................9

Auto-Off ...........................................................................................................................9

Hold ................................................................................................................................10

Beeper Disable ................................................................................................................10

Resistance .......................................................................................................................11

Current ...........................................................................................................................12

Function Access Summary .....................................................................................................12

Principle of Operation............................................................................................................13

Field Applications ..................................................................................................................14

Pole Ground Rods ...........................................................................................................14

Service Entrance or Meter................................................................................................15

Pad Mounted Transformer ...............................................................................................16

Transmission Towers ........................................................................................................17

Central Office Locations ..................................................................................................17

Service Panel ...................................................................................................................18

Phone Pedestal................................................................................................................19

Above Telephone Space...................................................................................................20

General Measurement Notes ...........................................................................................20

Quick Reference Card............................................................................................................21

Calibration Check Loop .........................................................................................................21

Commonly Asked Questions for Clamp-on Ground Resistance Measurements.......................22

Maintenance .........................................................................................................................23

Battery Replacement Procedure .............................................................................................23

Troubleshooting.....................................................................................................................24

Repair and Calibration...........................................................................................................24

Technical and Sales Assistance ...............................................................................................25

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1

WARNING

! !

These safety warnings are provided to help ensure the safety of personnel and
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 to help ensure proper alignment.

• ERICO

®

even if the equipment is properly operated and correctly grounded.

considers the use of rubber gloves to be an excellent safety practice

International Electrical Symbols

This symbol signifies that the instrument is protected by double or reinforced
insulation. Use only specified replacement parts when servicing the instrument.

This symbol signifies CAUTION! and requests that the user refer to the user

!

manual before using the instrument.

Risk of electric shock. The voltage at the parts marked with this symbol may
be dangerous.

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2

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 Tester Model EST401 is shipped with a hard carrying
case, one 9V battery (not installed), an Instruction Manual and a calibration loop. The
manual and calibration check loop are located behind the “egg crate” foam on the inside
of the carrying case cover.

Important Information - Proper Operation

The proper operation and measurement accuracy depends on the proper jaw closing. For
any measurement make sure that the jaw mating surfaces are clean and that no foreign
matter obstructs their closing.

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3

Description

The Ground Resistance Tester Model EST401 measures ground rod and small grid resistance
through any season, without the use of auxiliary ground rods. Clamp-on ground resistance
testers are used in multi-grounded systems without disconnecting the ground under test.
The EST401 simply clamps around the ground conductor or rod and measures 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.

The EST401 includes a current measurement function. The probe’s high sensitivity enables
measurement of leakage current flowing to ground or circulating in ground loops down to
1mA and neutral currents to 30Arms. This feature provides additional information which is
becoming vital as distribution ground networks carry higher levels of noise and harmonics
which affect power quality.

Battery life information is given 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.

Product Construction

The EST401 body cases are built of Lexan
ed in a double-walled Lexan shell (or equivalent polycarbonate) 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, meet or exceed IEC (International Electrotechnical Commission)
standards. The products have also been designed to meet IEC 1010.

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) 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 kcmil) 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.

®

for rugged use. The probe heads are encapsulat-

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 (or equivalent polycarbonate) 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.

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4

Electrical Specifications

Ground Resistance

Measurement Range Resolution Accuracy*

Range

0.1 to 1.00Ω 0.01Ω ± (2% R ± 0.02Ω)

1.0 to 50.0Ω 0.1Ω ± (1.5% R ± 0.1Ω)

Autoranging 50.0 to 100.0Ω 0.5Ω ± (2.0% R ± 0.5Ω)

0.01Ω to 1200Ω 100 to 200Ω 1Ω ± (3.0% R ± 1Ω)
200 to 400Ω 5Ω ± (6.0% R ± 5Ω)

400 to 600Ω 10Ω ± (10% R ± 10Ω)

600 to 1200Ω 50Ω Approx. 25% ± 50Ω

Ground or Leakage Current

Measurement Range Resolution Accuracy*

Range

Autoranging

1mA to 30.00A rms

R = Reading
* Reference conditions: 23°C ± 3K, 50% RH ± 10%, battery at 8V ± 0.2V, external

magnetic field < 40A/m, external electrical field < 1V/m, conductor centered, loop
resistance noninductive. Accuracy % of Reading, Frequency: 50/60Hz.

1 to 299mA 1mA ± (2.5% R + 2mA)

0.300A to 2.999A 0.001A ± (2.5% R + 2mA)

3.00A to 29.99A 0.01A ± (2.5% R + 20mA)

Resistance Measurement Frequency: 2403Hz
Voltage Generated into the Loop: Approx. 60mV rms
Resistance Overload: OL displayed above 1200Ω
Current Measurement Frequency: 47 to 800Hz
Influence of Frequency: Add 7.5% to the reference specification
Current Overload: OL displayed above 29.99A rms

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5

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
Jaw Cover Material: Lexan with 10% fiberglass charge (UL94V0) or equivalent
LCD Cover Material: Clear Lexan (UL94V1) or equivalent
Color: Gray body, red jaws
Jaw Window Diameter: 1.25” (32 mm)
Jaw Opening: 1.38” (35 mm)
Operating Temperature: 14° to 131°F (-10° to 55°C)

Operating Humidity: 10 to 90% RH @ 14° to 104°F (-10° to 40°C),

75% RH @ 131°F (55°C)

Storage Temperature: -22° to 158°F (-30° to 70°C)
Altitude: Operational - 2000 m; Storage - 12000 m
Power Supply: 9V Alkaline (IEC 6LF22 or NEDA 1604A)
Battery Life: Typical: 8 hours or approx. 1000 measurements of 30 seconds
LCD: 3-3/4 digit, 1.73 x 1.10” (44 x 28 mm)
US Design Patent: No. 362,639

®

920A (UL94V2) or equivalent

Safety Specifications

IEC 1010-2-032 (Class 2), Double Insulation

Working Voltage: 150V, Cat. III - Pollution Degree 2

Environmental: IP30 (Protection Index) EN 60529 Ed. 92

Vibration Test: IEC 68-2-6
Shock Test: IEC 68-2-27
Drop Test (1 m): IEC 68-2-32
Max A Overload: 100A continuous, 200A (< 5s) 50/60Hz

Electromagnetic Compatibility: Emission: EN 50081-1 Ed. 92

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300V, Cat. II - Pollution Degree 2

IK04, EN 50102 Ed. 95

OL displayed above 29.99A rms

Immunity: EN 50082-1 Ed. 97

6

EST401 Controls

1

2

7

EST401

GROUND TESTER

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.

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3

4

6

5

Figure 1

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.

7