Solar panels, also known as solar photovoltaic (PV) systems, are a solid investment to reduce your energy costs and carbon footprint. However, there may come a time when you need to disconnect your solar panels, whether for maintenance, replacement, or relocation. While it might seem daunting, disconnecting solar panels is straightforward when done correctly and safely. Follow this guide to disconnect your solar panels confidently and safely.
Safety Precautions: What To Know Before Disconnecting Solar Panels
Solar panels are electrical components that pose risks if not handled properly. Here are some safety precautions to take.
Wear Proper Safety Gear
Protect yourself from potential electrical hazards when working with solar panels. Wear safety gear, including insulating gloves, work boots, safety glasses, fire-rated clothes, and a hard hat.
Choose the Right Time
You can’t simply “shut off” solar panels like traditional electrical appliances. We recommend performing the disconnection early in the evening or before sunrise for maximum protection.
Disconnect the Load
Before starting the disconnection process, shut off the DC and AC circuit breakers so there’s no electrical load connected to the solar panels.
Steps To Disconnect Your Solar Panels
Now that safety precautions are in place, here’s a comprehensive guide to disconnecting solar panels.
1. Turn Off DC and AC Disconnect Switches
The first step in the disconnection process is to shut off the main power sources. Locate the AC disconnect switch and turn it off. This switch lies between the inverter and the main electrical panel. Find the DC disconnect switch from the PV array to the combiner box or inverter input and turn it off.
2. Cover the Solar Panels
Even when disconnecting during low-light hours, cover the panels. Use opaque cloths to cover the surface of each panel. Then, secure them in place to prevent them from blowing away.
3. Measure the Voltage of Each String
Before physically disconnecting anything, verify there is no residual voltage. Use a solar battery tester or multimeter to measure the voltage at the solar charge controller. The readings must be close to 0V before you proceed.
4. Disconnect the MC4 Connectors
After confirming the voltage levels are at safe values, disconnect the panels. First, locate the MC4 connectors at the end of each solar panel. Use an MC4 disconnection tool or a socket wrench to unplug each connector.
5. Protect the Exposed Connectors
After disconnection, safeguard the exposed electrical components by covering each MC4 connector with electrical tape. Fully cover all exposed metal parts to prevent potential electrocution risks during transportation or storage.
6. Remove Mounting Hardware
If you need to completely remove the panels from their installation site, identify all bolts, screws, and clamping nuts securing the panels. Use appropriate tools to remove the mounting hardware, and then carefully lift and remove each panel from its mounting location.
7. Inspect the Panels and Electrical Components
After removing the solar panels, inspect both the panels and electrical components. Look for any signs of wear or damage on the panels, and check the connectors and cables for signs of deterioration. Likewise, check that there are no loose wires or exposed connections.
8. Store the Panels Properly
If you plan to store your solar panels after disconnection, preventative measures help prevent damage. After removal, clean the panels using a soft cloth and a mild detergent. Store the solar panels away from direct sunlight. Place them flat to prevent warping or damage during storage.
How To Turn Off Your PV System During an Emergency
You need to know how to safely shut down a solar PV system in an emergency. The National Electric Code (NEC) has specific requirements for Rapid Shutdown (RSD) systems.
Figure 2: Rapid Shutdown (RSD) system for residential and small commercial applications – Source: ABB & DMB Solar
Identifying and Using RSD Systems
RSD systems vary in appearance, but they all serve the same purpose. Some systems feature a simple on/off switch, while others have a prominent red button for activation. Look for the RSD label to quickly locate the shutdown mechanism in emergencies.
Why Rapid Shutdown Matters
While not all small residential systems require RSD equipment, installing one is a significant safety benefit. In emergencies such as fire, RSD quickly de-energizes the system. This mitigates the risk of electric shock to emergency personnel. RSD allows responders to work safely without the risk of contact with high-voltage components. Likewise, updating to an RSD-enabled system in old installations can enhance overall safety.
Professional Installation and Testing of RSD
Proper setup and functionality of RSD systems require professional installation. Professional solar installers can assess your current system and recommend suitable RSD options. Installers will also check all connections and test the system to verify it meets NEC requirements and remains in proper working condition.
Some PV homeowners do not know about RSD equipment because their installation is small enough not to require it. Installing this or a similar system is always advisable. In cases where there is a connection to the grid, you need an RSD system.
