Megger Test

One of the best methods to test electrical insulation condition is a megger test. It is well known as insulation resistance meter test.  For finding defects and punctures in insulation of things like electric wires, antenna mounts, motor winding and many more. This method of testing is used widely all over the world.

Dedicated to excellence, Megger group has manufactured number of megger test equipments till now and they are still producing innovative test equipments to give better results. Even today, their expertly designed test kits are in demand across the world. It has a great application on small scale and even in large scale industries. Megger insulation test equipments are of great capability. They are manufactured as per universal standard specification norms.

Megger test procedure

The only compulsion for this test is a high voltage. For testing, a DV voltage of up to 1000 volts is applied to the insulation. Readings are noted as variations in insulation resistance with respect to time. Readings are taken and recorded with regular intervals on 1 minute and 10 minutes and many other interval times. Megger test is mainly used for purposes like finding the quantity of moisture in insulation or winding, current leakage over wet and bad surfaces of insulation, Winding decay or defects due to long term use beyond expiry and many more.

Megger test equipments

There are number of megger test equipments and instruments which suit different criterias. For every requirement, it has a fine solution. Some of them are listed below-

Some advanced insulation testers like MIT510/2 and MIT520/2 are good at tests with wide range of measurements. They provide duel operation mode. They use reliable electric line supply and even work on rechargeable batteries. They use different test voltages like 250, 500, 1000, 2500 and 5kv. It gives perfect analytical information. They give high quality performance with safety and comfort. Moreover there megger test devices are portable with different sizes. They are easy to carry on. Megger test has great applications in different markets such as Industrial Substations, mining, airports, Petrochemical, Railways, Wind/Renewable Energy with other electric utilities and many more.

Megger tests are available with expanded line of insulation testers. Their automated standardized tests include step voltage, Dielectric Discharge tests, absorption ratio and even PI. These testers accompany with different types of test clips to meet your need. You can use large test clips for larger test areas or compact test clips for with reserved access area. For testing at low voltages specially designed control circuit test clips are there. With advanced megger test equipment, up to five different tests can be run and programmed automatically. With compatible software you can monitor results on computer as these equipments are provided with USB connectors. It makes easy to run and retrieve information, reading and discrepancies with respect to result. It also allows the hardcopies of test prints.

In short, megger test is the best option available for insulation testing at affordable costs, for all purposes and in multiple industries with complete reliability.

Resistivity
S oil Ohm-cm (Range)
Surface soils, loam, etc. 100 - 5,000
Clay 200 - 10,000
Sand and gravel 5,000 - 100,000
Surface limestone 10,000 - 1,000,000
Shales 500 - 10,000
Sandstone 2,000 - 200,000
Granites, basalts, etc. 100,000
Decomposed gneisses 5,000 - 50,000
Slates, etc. 1,000 - 10,000

Effect of Added Salt in soil.
Percent by Weight of Moisture R esistivity, (Ohm-cm)
0.0 10,700
0.1 1,800
1.0 460
5.0 190
10.0 130
20.0 100
*For sandy loam; moisture content, 15% by weight; temperature 63º F (17º C)

Temperature
C        F    R esistivity (Ohm-cm)
20 68 7,200
10 50 9,900
0 32 (water) 13,800
0 32 (ice) 30,000
-5 23 79,000
-15 14 330,000
*For sandy loam; 15.2% moisture