How a century-old leader in electrical testing redefined the solar toolkit

14 March 2022


Imagine you’re commissioning a large-scale solar project. You started measuring voltage to verify that the wiring is correct and the system works as expected. The crew lead wants you to log data into a mobile app, but you have high-voltage gloves on both hands to protect against electrical shock.

Operating the app with gloves on won’t work. Removing the gloves to upload data would waste a lot of time.

A better, more convenient option is to perform all testing first and upload the data later through a quick link between the meter and your phone.

This is just one of many details, large and small, that Megger considered when developing solar test equipment to address the needs of solar technicians.

Test equipment can vary a lot based on the job at hand. A solar technician’s job is to catch damage to conductors before it’s too late and provide an efficient and reliable commissioning process. You have to rule out weather-related impacts on product performance and installation quality, and spot equipment susceptible to failure before a catastrophic event occurs.

Functional test equipment itself won’t assure that you can meet rigorous safety and commissioning standards. The equipment has to be user-friendly, easy to understand, and backed by thoughtful customer support.

A leader in electrical testing innovation


Megger’s roots extend to the start of the electricity age. They go all the way back to the time when Thomas Edison was designing direct current electrical systems. George Westinghouse was developing alternating current systems. And their contemporary Sydney Evershed invented the world’s first instrument to accurately measure insulation resistance for electrical conductors.

In the early 20th century, as the use of electricity spread rapidly, Evershed’s invention—a megohmmeter, which came to be known as a Megger instrument—was crucial for testing the ability of ground systems to discharge dangerous fault currents.

For more than 130 years, Megger has remained at the forefront of electrical testing equipment development, consistently exceeding industry standards in metering, durability, functionality and performance.

Starting with the insulation tester, Megger has introduced the industry to numerous firsts.


Solutions for solar technicians

Megger rolled out a solar testing toolkit to improve standards for PV system quality control checks at the point of commissioning and during routine operations and maintenance.

Our insulation resistance tester, the MIT2500, is the perfect tool to ensure and validate system safety, preventing damaged wires from causing ground faults, electrical shock and fire hazards. The MIT2500 includes a unique guard terminal that helps avoid inaccurate diagnostic results from surface leakage currents.

Our digital clamp meter, the DCM1500S, gives solar technicians the flexibility to measure and record voltages up to 2,000 Vdc; true RMS up to 1,500 Vac; and amperages up to 1,500 A on the ac and dc sides of the system. Additional features include temperature measurements, an automatic flashlight, a no-touch voltage sensor, inrush current measurements and data logging via Bluetooth.

When you need an irradiance meter to validate system performance, just hold our PVM210 in the palm of your hand. Point the sensor in the same direction as the solar modules to see how much sunlight is striking the array. Read the array current and sunlight intensity at the same time to validate that the system is performing correctly.

To check for hotspots on the front or backside of a PV array that can lead to reduced production or safety hazards, use our thermal camera, the TC3231. By blending thermal images over normal camera images, the TC3231 can also pinpoint bad wiring connections within combiner boxes, inverters and AC panelboards.


Greater than the sum of its parts

Many contractors aren’t taught to use a megohmmeter with a guard terminal. Weather conditions can cause a wide variety of readings, creating confusion about whether the results are acceptable or safe.

In addition to making test equipment that’s easy to use, Megger provides training materials, user manuals, workshops and videos to ensure our products are easy to understand. Simple instructions and high-quality images make a big difference when you’re learning on the job.

Our rugged, well-organized tool case can even do more than give space to hold test equipment, probes, alligator clips, temperature sensors and more. Technicians can use it as a staging place in the field.

As we get closer to the NABCEP 2022 Continuing Education Conference, March 28-31

in Phoenix, Arizona, stay tuned to the Megger blog for a closer look at the DCM1500S and MIT2500, must-haves for every solar technician.

If you’re attending NABCEP 2022, be sure to visit us at Booth #2 to see the Solar Test Kit up close and talk to the Megger team.