On 11th July 2024, the fire department called Penrith Solar Centre to help extinguish a rooftop string system fire. String inverter solar systems have high voltage running through them that can’t be switched off because the system has no rapid shutdown.
The fire department called our number listed online and got hold of our operations team. They’re the ones who man the phones every day.
Jack from our service department hopped on the call. He’s got a great sense of humour and immediately asked the fire department if the phones or the roof was on fire. That inspired a few nervous laughs in the office. Calm and cool under pressure, Jack walked the fire brigade through their initial queries.
Here’s what happened in his own words:
“I had the fire department on the phone they said they were at the customer’s house and there was a fire up on the roof involving the DC solar system. They had isolated the fire to the roof only, but they didn’t have the expertise in regard to how to turn the system off. They needed a solar technician to come out and do it. They said that they called three electricians and we were highly recommended. We’ve done a lot of systems in Cambridge Park.”
Once our team found out no one was in danger, the whole office started buzzing. It was a real drama unfolding. Everyone wanted to help.
Our head of operations, Al, jumped on the phone and immediately started calling every one of our fourteen trucks on the road to find the one closest to the fire. Our operations and service teams stepped up because that’s who we are. We’re invested in supporting our community.
White Truck, under the leadership of Aaron, was the closest and arrived on the scene.
Penrith Solar Centre Installation Team Steps Up to Help Local Fire Department on Site
Here’s what happened, in Aaron’s own words:
“Jory (our install manager) got me on the phone. He said that there was a fire, that it was most likely a rooftop isolator that was installed by another company, and to get out there as quickly as possible to try to get it safe and under control.
When we got there, the fire department was already there. They weren’t allowed on the roof because they were worried about the high-voltage DC electricity running through the wires, so they just isolated what they knew downstairs, which was the inverter and the AC breaker inside the switchboard.
We got our gear, harnesses, and tools — what we thought we needed for the roof. Basically, we checked that the system was off downstairs, got up on the roof, and set up a harness point so we could work safely.
I could see that the smoke and fire had sort of dissipated a little bit. We put a blanket over the panels before we did anything else to reduce the output of the system. By reducing the power, we were able to disconnect the MC4 connectors between each panel without arcing (causing electrical sparks).
So, when we did that, we could then disconnect and take apart the isolator (a safety switch) eliminating the high voltage DC power in that component. We pulled the isolator apart, and it was pretty much completely destroyed.
We replaced the damaged part with a new connector (called a junction box) on all the wires. This made sure the wires were safe and wouldn’t touch each other. We put the junction box under the panel and secured everything back in place.
After finishing on the roof, we went back downstairs. We labelled everything clearly and used a bit of copper to lock off the breaker to prevent anyone from turning the system back on without proper checks.
We were there altogether maybe half an hour to 45 minutes. Luckily, the guy’s house didn’t go up in flames, which is good that we were nearby for that situation and the homeowner was safe.“
If you’re interested in learning about arc faults and why they’re dangerous, you might want to check out the following article titled, What Are Arc Faults in a Solar System?
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What You Need to Know About Rapid Shutdown in Solar Systems
A DC string system doesn’t have rapid shutdown. True rapid shutdown (a switch that shuts off electricity coming from the solar panels) is a feature of Enphase microinverter systems only.
While string inverter systems are popular because of their low price point, there’s a great deal of misinformation out there about how safe they are. Some lead-generating websites and blogs (that make their living retrieving quotes for string systems) like to harp on how safe they believe string systems to be.
When it comes to fire safety, belief is not enough to assure us.
Enphase microinverter solar systems have a true rapid shutdown. It fully eliminates the DC power coming from the roof to the side of the home where the inverter is mounted next to the main switchboard.
No other system can fully shut down and eliminate electricity coming from the solar panels. Because each solar panel has a microinverter mounted underneath it to convert the DC power to AC power, each microinverter can be directed to cut off power from its solar panel.
String systems cannot do this because of the way they are designed, manufactured, and installed. But beware: there are a couple of string system manufacturers that claim to have rapid shutdown. This is not accurate.
In such a system, the string inverter can command those panels to output less voltage, about 1 volt per panel, but it never fully eliminates it the way a microinverter system will.
If your system has 20 panels and they’re each still outputting 1 volt, that’s 20 volts the fire brigade has to deal with. They won’t risk it. They didn’t risk it here.
If you’re interested in learning a bit more about the rapid shutdown feature in a solar system (and how it can save your home), you might want to check out the following article titled, How Important is Rapid Shutdown in a High Voltage DC Solar System?
Fire Safety and Solar: A Spark Reminder
Now you know a bit more about who we are and how we troubleshoot solar emergencies. The fire department knew who to call for help with a string inverter solar system – cheap solar equipment that solar installers push because of its low price point.
At Penrith Solar Centre, safety is our top priority. We install Enphase microinverters and Powerwall 3 systems because they are the safest solar technology available.
Don’t worry if you saved money with a lesser installer and lesser equipment. We’ll be there to help the fire department if anything goes wrong with it.
If you’re interested in learning a bit more about how the type of system you choose can affect your family’s safety, you might want to check out the following article titled, Solar Safety: Microinverters vs. String Inverters.
