Megger DET3TD Offers

DET3 Contractor Series 3-Terminal Earth/Ground Resistance Testers

The DET3TC includes a current measuring function for ART (Attached Rod Technique) testing capabilities. With this added function, on-site grounds can be tested 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 polypropylene carry case - everything you need to start testing in one package. Optional terminal adapters are available for acceptance of a variety of test leads.

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 ground testing. In addition to this 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 measurement of ground voltage. They can measure resistance from 0.01 ohms to 2 kΩ. Also, to allow accurate testing in noisy environments, the instruments are capable of rejecting noise up to 40V peak to peak.

The Megger ground testers are powered by eight AA 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 measurement method with ART (Attached Rod Technique), which allows electrode testing without disconnection and also leakage current measurements down to 0.5 mA.

Features

• 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
• Large, clear LCD that can be read in ambient lighting
• Noise rejection to 40 V pk to pk allows accurate testing 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

Applications

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 lightning strikes and induced voltages, improves the 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 on ground rods and cause metallic corrosion. Catastrophic 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 grounds
• Lightning protection systems
• Residential grounds
• Machinery safety grounds
• Computer and communication system grounds
• EMI/RFI system grounds
• Antenna and pedestal grounds
• CATV system grounds