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5 Common Solar Faults That Require Immediate Attention!

As a solar owner, you want your system to operate smoothly and efficiently at all times. But the truth is, even the best systems can experience faults from time to time.

In this week’s blog, we’ll be outlining common faults that we’ve witnessed with our own clients’ solar systems over the years. It’s important to us that our clients are well-informed and know what to look out for, which is why we encourage you to reach out if you have any questions regarding your solar. Also, by taking a more proactive approach with your solar system, you can expect to avoid costly repairs and replacements down the road.

Here are the five common faults…

Water in Isolators

A DC isolator is an essential component to any solar system. Basically, it is a switch that can be opened and closed to isolate the solar panel array from the inverter. By doing this, it allows for safe and effective maintenance of the solar PV system and in most cases, allows replacement of the inverter without the need to get on the roof.

DC isolators can also be used to isolate a faulty string, which means if you have more than one, part of your solar system will still be able to generate power. However, isolators are the leading cause of fires in a solar system.

The most common type of fault which leads to a risk of fire is caused by water ingress. This can occur if the isolator has been exposed to any of these following factors.

  1. The enclosures prolonged exposure to the Australian UV causing the enclosure to crack or blister

  2. No Weathershield cover installed on the rooftop DC Isolators

  3. Lack of glands on the conduit entries into the isolators

  4. Failure to glue conduits or their fittings into the isolators

  5. Top entries into the DC isolators at the inverter

  6. Internal contacts failing in DC isolators causing a short

Therefore, If you suspect that your isolator is faulty or installed incorrectly, let us know as soon as possible so that we can check it out right away to ensure that it’s free from water ingress and in good working condition before a fire occurs

Burnt-out MC4 Plugs

MC4 stands for multi-contact 4mm and they are a common type of solar connector used to connect solar panels to each other and to the solar inverter. However, MC4 plugs can sometimes become burnt out, for a number of reasons. The most common cause for a burnt out MC4 Plug is a loose connection between the internal pin leads and the solar panel. This can happen if incorrectly matched MC4 brands have been installed, or if the connections are not tightened properly. It is Australian Standard to install the same manufacturer and model MC4 to prevent this from happening.

As a result, the electrical current flowing through the solar panel can cause the internal pin leads to overheat and melt, causing the plugs to burn out. In some cases, this can also damage the solar panel or inverter itself.

Therefore, it is important to have them checked and replaced by a qualified solar electrician as soon as possible to avoid any damage to your panels and to your property.

Inverter Faults

Solar inverters are an essential part of any solar system, converting the DC electricity generated by the solar panels into AC electricity that can be used by household appliances.

However, solar inverters can sometimes experience faults, which will stop the solar panels from working properly, causing higher than normal electricity bills. One common fault is an error code appearing on the display. This can indicate a problem with the solar inverter itself, or with another component in the system.

If you see an error code on your solar inverter, be sure to get in touch with our team. We’ve resolved many of our clients’ solar inverter issues over the phone and in some cases, we may need to send out an electrician to come and take a look at your system.

Faulty Wiring

Faulty wiring is another common solar system failures. This can happen for a number of reasons, but the most common cause is poor or incorrect installation. While solar panel manufacturers have improved the safety of their products in recent years, solar panel installations are sometimes performed by inexperienced subcontractors who may fail to ensure that wires are properly secured, mechanically protected or tested correctly.

Another common cause of faulty wiring is exposure to the elements. Now, although the DC cables are rated to some UV exposure, they are required to be mechanically protected by means of conduit or similar means. Because the panels generate electricity it means they generate heat which vermin love! Birds nesting, possums and other rodents don't mind it underneath your panels but the problem is it can cause overheating, damage to the panels voiding warranty, earth faults (PV Isolation) and/or potential fire issues.

In order to prevent this, it is important to make sure that your panels and its associated wiring are installed and maintained by qualified electricians (like us!). That way, you can be assured that your system is safe and reliable for years to come.

Panel Defects

Solar panel defects can occur for a number of reasons, including weather, manufacturing defects, damage during shipping, or installation errors.

Here are some common examples of panel defects:


Solar scarring is a type of damage caused by the sun's UV rays which can break down the silicon in the panels and cause them to become brittle. Over time, this can lead to cracks and holes in the panels, which can reduce their efficiency and cause them to malfunction.

Snail Trails

Snail trails are a type of defect that usually appears when there are existing physical defects on the panels, such as microfractures, which then create a pathway for undesirable chemical reactions in the solar cells.

Although snail trails are not a huge concern, they may indicate other issues with your solar panels (e.g. microfractures), hence why they should not be ignored.

Microfractures / Microcracks

Microfractures are small cracks that can form in solar panels over time. These cracks can allow moisture and dirt to get inside the panel, interfering with the solar cells and reducing the amount of power that the panel produces. PV Isolation faults (Earth faults) can be directly related to this type of panel failure.

In some cases, microfractures can cause complete panel and system failure.

Hot Spots

Hot spots occur when a certain point in the panel becomes overheated, typically due to shading from obstacles such as trees or buildings. This can cause the solar cell to become less efficient, may even damage the cell or potentially cause a fire.


This occurs when the layers of the solar panel begin to separate, due to either manufacturing defects or environmental factors such as extreme temperatures or UV exposure. Delamination can cause a loss of power output and can make the solar panel more susceptible to physical damage.

Panel defects can reduce the amount of power that the panel produces, and in some cases, they can cause the panel to stop working entirely. Therefore, it is important to inspect solar panels regularly for defects.

The good news, however, is that solar panel manufacturers typically offer warranties that cover panel defects, and one of the things we do here at ASD is help you to take advantage of this coverage.

There are many benefits to having solar installed on your property. However, we can’t stress enough how important it is to have your solar system and its components regularly checked for signs of damage or wear and tear. Preventative maintenance not only helps maintain maximum safety but can also ensure that potential problems are detected as early as possible – before they become too costly to repair. Not only that, but it also helps to keep warranties up to date and responsible parties accountable for their warranties offered.


If you would like to learn more about how we can help you with any aspects relating to your solar system or would like to book a Solar Health Check, get in touch with us today by submitting an enquiry here or simply call our team directly at 1800 765 237.

Our qualified and experienced solar experts will assist you in ensuring that your solar system will be able to provide you with sufficient energy for many years to come!

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