Installing solar panels: Your electrical testing toolkit

31 March 2021


It’s been a while since we’ve talked about solar power on the blog. Well, if we’re being honest it’s been a while since we’ve talked about much of anything on the blog. Sorry, we promise we weren’t trying to ghost you; time just got away from us.

But spring is officially here, the sun is finally shining – after a dreadfully long winter, and now seems like a great time to introduce our newest blog – the 4 tools you need when you’re installing solar panels.

Before we really get into it though, let’s just have a quick chat about solar energy.

Whether you like it or not, solar power is on the move. The upward move.

It’s the cleanest and most abundant renewable energy source on the planet, and in the past decade, the solar power market in the United States has practically doubled every year. With over 2.6 million solar installations across the country – ranging from rooftop solar panels for your home to large-scale solar systems powering our utilities – there’s enough clean electricity to power over 16 million homes.

And sure, solar energy is not for everyone. If you live somewhere in the middle of a dark, rainy forest with lots of cloud cover and little natural light, it’s probably not your best bet for renewable energy. Or maybe you just hate change and new technology. Totally fair. We all have our quirks.


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But, if you’re looking to cut energy costs, protect the environment, get a great return on your investment, or simply commit to sustainability, solar panels may be the answer.

We’re not here to convince you one way or another though.

We’re really just here to help you with the installation, commissioning, and maintenance of your photovoltaic (PV) system, if you’re choosing to go solar.

And that’s where this blog comes in.

A solar PV system is an electrical system, which means… it needs electrical testing! Duh.

What tools do I need to run electrical tests on my solar panels?

Whether you’re at the beginning of your solar power journey or you’re a technician who’s installed hundreds of solar panels over the years, there’s a few electrical testing tools that you should have in your solar toolkit.

1. Solar Irradiance Meter – These pocket-sized meters are ideal for choosing optimal photovoltaic panel position during installation. Plus, you can typically use this handy tool with just one hand, since it’s so compact, which makes it the perfect instrument for working on a sloping roof or at the top of a ladder. With a solar irradiance meter, you can choose the optimal incident angle and positioning of solar panels, as well as measure the solar power for panel short circuit calculation.

2. Solar Clamp Meter – If you’re working with large AC or DC solar power systems and equipment, you’ll definitely need a solar clamp meter. From installation to maintenance and monitoring, a clamp meter enables you to easily measure voltage, current, resistance, diode, capacitance, temperature and frequency. Plus, certain advanced models can be paired with your smart phone for remotely monitoring measurements with built-in Bluetooth functionality. How sweet is that? A proper clamp meter with a tactile barrier below the instrument’s jaws also ensures a safe working distance between the operator’s hand and live uninsulated conductors.

3. Insulation Resistance Tester – Depending on the solar power system you’re working with, you may need either a 1kV or a 2.5kV insulation tester. The level of voltage is up for negotiation, but insulation resistance testing is a non-negotiable. You’ll need a handheld, lightweight insulation tester that can produce the required voltage (typically up to 2,500 Vdc for solar applications) for testing insulation resistance in PV systems.


Download Insulation Resistance Cheat Sheet


IR testing is an important step to verify the integrity of conductors associated with a photovoltaic array, and it’s often a required test during startup and maintenance activities. Failure to identify ground faults early can result in major delays and financial losses, which we always want to avoid, right? Luckily, a simple IR test can quick identify dangerous ground faults from compromised wires. Still not convinced? Failure to identify these faults prior to system operation can present risk of shock, fires, and property damage. Not good, guys. Insulation resistance testing is the standard best practice for ensuring optimal system performance and safety.

4. Power Quality Analyzer – With constantly fluctuating outputs, power quality issues can often arise in solar systems. Using a power quality analyzer, you can easily troubleshoot power quality issues within your solar installation’s battery banks, inverters, switches, breaker or fuse boxes, and electric meters. While it’s not necessary for installation, it’ll come in handy whenever things go wrong. If you’re interested in learning more about solar power quality issues, click here to download our free eBook.

5. Thermal Imaging Camera – If your solar installation has a battery bank, you may want to look into adding a thermal imaging camera to your tool arsenal, as well. These cameras can quickly identify hotspots, compared to traditional battery testing procedures. Also, battery banks are often located in tight spaces, so performing strap measurements might simply not be an option. Fortunately, thermal imaging cameras are compact and handheld – a great tool for solar troubleshooting.

6. Battery Impedance Tester – We mentioned battery testing above, but let’s get into that a little more. A battery tester will help you determine the health of your battery cells by taking measurements of the most important battery parameters. If you’re responsible for the maintenance and operation of a large solar installation with a battery bank, then a battery impedance tester is probably a non-negotiable for you. However, if your solar power system doesn’t have a battery bank, then you obviously do not need a battery tester, alright?

There you have it – all the tools that you need (or might need) in your solar installation and maintenance toolkit. For more information on Megger’s renewable products and solutions, please click here