Megger DET3T Specifications

ET3 Contractor Series

D

arth/Ground Resistance Testers

E

DET3 Contractor Series

3-Terminal Earth/Ground Resistance Testers

■

2 and 3 point testing

■

ART (Attached Rod Technique)
testing capability

■

User selectable test voltage (25/50 V)

■

Choice of digital or analog display

■

Warning indicators prevent test failure

■

IP54 rated

■

Complete with leads, stakes and
rugged carry case

■

Simple one button operation

DESCRIPTION

Megger’s already popular 3-terminal ground testing
instrument family includes the following models:

Model Description

DET3TD

DET3TC The revolutionary new model with the

Using ART method with the DET3TC
to test commercial ground without
disconnecting the system

start testing in one package. Optional terminal adapters
are available for acceptance of a variety of test leads.

For basic requirements it provides digital
ground testing and bond testing capabilities

capability of testing on-site grounds without
disconnecting the utility connection.

The DET3TC includes a
current measuring function

T (Attached Rod

for AR
Technique) testing
capabilities. With this
added function, on-site

ounds can be tested

gr
separately without having
to remove the utility
connection (as explained
further in this document).

The complete kit of
instrument, test leads,
stakes, batteries and
calibration certificate is
delivered in a tough

opylene carry case

polypr
– everything you need to

All models are rated to IP54, making them truly outdoor
instruments. They are designed to meet stringent safety
standards and are rated CAT IV 100V. The ground testers
have been designed to be easy to use – a large selector
switch makes selection of 2 or 3 pole tests easy with
gloved hands – and the design makes the fitting of
shorting links to perform 2-pole tests a thing of the past. A
large, clear, easy to read LCD and thumb-sized test button
also make the instruments particularly well suited to the
outdoor conditions of gr
ease of use feature, the ground tester automatically checks
the connection and conditions of the P spike, C spike, and
also the level of ground noise, indicating the status on the
display. The instruments also include a voltmeter to enable

ement of ground voltage. They can measure

measur

esistance fr

r
testing in noisy environments, the instruments are capable
of rejecting noise up to 40V peak to peak.

The Megger gr
batteries which are widely available and also give
excellent testing time – the status of these batteries is
given by a bar graph on the LCD, allowing the operator to
decide when to change the batteries before they expire.

By using the optional ICLAMP with the DET3TC, the user
can augment the traditional fall-of-potential measur
method with ART (Attached Rod Technique), which allows
electr
current measurements down to 0.5 mA.

om 0.01 ohms to 2 k

ound testers are powered by eight AA

ode testing without disconnection and also leakage

ound testing. In addition to this

. Also, to allow accurate

Ω

ement

ET3 Contractor Series

D

arth/Ground Resistance Testers

E

PPLICATIONS

A

Proper grounding provides many varied benefits to both
people and facilities. It lessens the chance of injury due to
faulty installation, reduces the likelihood of damage from

ightning strikes and induced voltages, improves the

l
performance of computer, communication and other
sensitive equipment and protects against static electricity
from friction. Over time, ground systems can degrade or
become ineffective.

Corrosion and weather influences exert mechanical strain

n ground rods and cause metallic corrosion. Catastrophic

o
events like lightning strikes or large fault currents can
cause instant degradation. In addition, facility expansion
can create different ground system needs.

The risks from ground system deterioration include
potentially deadly electrical shock situations, plant-wide
equipment damage, disruption in the performance of
sensitive equipment and heat build-up on a single piece of
electrical equipment.

The maintenance of an adequate low resistance ground
connection is essential to both the protection and
performance of any electrical system. Ground testing
should be performed both upon installation, to meet
design specification, and periodically thereafter in order to
maintain service. All models can also perform bonding
tests (using an ac signal), to determine that adequate
connection has been made from equipment to the
grounding system. Furthermore, the addition of a built-in
current clamp capability enables the testing of attached
grounds (ART) without lifting the utility connection.

Selection is easy. For basic requirements, DET3TD affords
ground testing and bond testing capabilities. Applications
to systems that have been connected to the utility feed are
simplified with model DET3TC, where a built-in clamp
input permits individual components of an expanded
system to be separately measured without extra
calculations.

Grounding electrodes from simple to complex systems can
be tested, including:

■

Primary and secondary electrical grounding systems

■

Utility pole gr

■

Lightning protection systems

■

Residential grounds

■

Machinery safety grounds

■

Computer and communication system gr

■

EMI/RFI system grounds

■

Antenna and pedestal grounds

■

CATV system grounds

ounds

ounds

FEATURES AND BENEFITS

■

Microprocessor control for improved error detection

■

Clear, unambiguous warnings and error indications
ensure the reliability of the reading and reduce test time

■

Simple to use, one touch operation improves efficiency

■

User selectable test voltage ensures that the units can be
used in agricultural environments

■

Rugged, weatherproof case to IP54 makes the units truly
outdoor instruments

■

arge, clear LCD that can be read in ambient lighting

L

■

oise rejection to 40 V pk to pk allows accurate testing

N
in noisy environments

■

Testing kits and certificates supplied — everything
needed to start testing immediately

■

Accuracy of 2% of reading enhances reliability of
measurements

■

Clamp model for Attached Rod Technique allows the
testing of the rod without the need for disconnection.

■

Voltmeter function included allows you to measure the
ground voltage and enhances operator safety

■

CAT IV 100V provides increased operator safety in
outdoor environments

Model DET3TC shown performing the classic fall-of-potential test method.