Your residential solar energy system produces clean energy every day. But that same power can become a serious hazard when an emergency hits. Knowing how to shut down your solar equipment safely protects your home, family, and first responders.
This guide provides a straightforward, step-by-step approach to manually disconnecting your system in various emergencies. We break down the process in clear language, drawing on real-world installations completed by MAG Solar. Even if you’ve never touched an electrical panel before, this guide will give you the confidence to act fast and stay safe when it matters most.
Key Takeaways:
- Solar panels generate power in daylight even if the system is off, so proper disconnection is essential to prevent shock or fire hazards during emergencies.
- Key isolation points include the DC switch (PV array), AC breaker (inverter), main service panel, and battery disconnect.
- Never restart the system on your own after an emergency. Contact a solar installer to inspect to verify safety, and properly re-energize the system.
What Does “Manual Disconnection” Mean
In solar PV systems, manual disconnection refers to the complete physical separation of all energized components from the photovoltaic (PV) modules to the utility grid. This means cutting off the DC input from the panels and AC output to your home and grid, and, if present, disconnecting any energy storage systems (ESS).
Why Manual Disconnection of Residential Solar Energy Matters?
- PV panels generate voltage anytime they are exposed to light, even when the inverter is off.
- Improper isolation can pose arc flash risks, electrocution hazards, and may damage your equipment during re-energization.
- In the event of fire, flooding, or severe weather, firefighters and utility technicians require absolute assurance that your system is not backfeeding energy into the grid.
IMPORTANT: Solar panels continue to generate voltage in daylight, even when the inverter is off. Never attempt disconnection if there is immediate danger. Always prioritize evacuation and call emergency services.
Take advantage of MAG Solar’s expert installation for a safer PV system. Save on electricity bills without worrying during emergencies.
Step-by-Step: Manual Disconnection Procedure for Solar Power Systems
Note: This procedure assumes a grid-tied solar system with a PV-powered inverter and integrated disconnect, as used by MAG Solar. Additional steps apply for other configurations (e.g., off-grid or hybrid with batteries).
Step 1: Confirm It’s Safe to Approach the Solar Panel System
Only perform disconnection if there is no immediate danger (e.g., visible fire or sparking). If so, evacuate and call 911.
PPE Recommended:
- Insulated gloves (Class 0 or better)
- Safety glasses
- Rubber-soled footwear
Avoid metallic jewelry or water contact.
Step 2: Conduct a Visual and Diagnostic Check
Inspect the charge controller or inverter display (e.g., STECA PR2020, Sure Sine 300) for errors like:
- E05: Internal overheating → Ventilation issue
- E09: Overload due to excessive current draw
Guarantee State of Charge (SOC) is above 50% if batteries are present; otherwise, switch off appliances immediately.
Step 3: Turn Off All Appliances and Sensitive Loads
Unplug high-consumption or sensitive devices such as HVAC systems, electric ranges, computers, and networking equipment. This prevents reverse energy spikes, protects your electronics, and limits how much electricity runs through your circuits during shutdown.
Step 4: Shut Down the Inverter – In the Correct Order
For PV Powered inverters (PVP2000W to PVP5200W), do this in two steps:
Step 1: DC Side OFF
- Locate the PV System Disconnect’s ON/OFF lever
- Turn the DC input switch to OFF
- Cover PV modules with an opaque tarp if possible during daylight
Step 2: AC Side OFF
- Flip the AC output breaker (Line 1 and Line 2/N) to the OFF position
- This isolates the inverter from your home and utility grid
- If the disconnect box includes a locking pinhole, insert a padlock to prevent accidental reactivation
This step guarantees the system no longer sends electricity generated by the solar panels into your home or the grid.
Step 5: Disconnect from the Main Panel
Go to your home’s main service panel. Shut off the dedicated breaker for the solar inverter. Then, flip the main circuit breaker OFF if advised by emergency services or the utility provider.
Tip: Refer to NEC Section 690.64(B) – the inverter must be connected to a dedicated breaker, and it should never share circuits with other home devices
Step 6: (If Present) Disconnect the Battery Storage System
For systems with battery backup:
- Locate the battery disconnect switch or breaker
- Disconnect the positive terminal first, then the negative
- Some advanced systems will require a digital command via your solar app or gateway device
- Never short-circuit terminals. Wear insulated gloves and follow Lockout Tagout (LOTO) procedures where applicable
Step 7: Confirm Full Isolation
Your system is fully disconnected if:
- The PV disconnect switch is OFF
- The inverter display is blank or showing “OFF”
- The AC breaker is OFF
- You’ve verified no backfeed at the main panel
- Battery voltmeter reads 0V at the load terminals (If applicable)
Emergency Situations That Require Manual Disconnection
- Fire in or near the building (roof access or wiring)
- Flooding near inverters or AC panels
- Utility company instructions for load shedding or backfeed prevention
- Lightning storm with direct roof impact
- System malfunction (e.g., overheating inverter, error codes like E05/E09)
- Visible damage to roof-mounted arrays or wiring due to high winds or fallen branches
Pre-Emergency Residential Solar Panel Installation
From a best-practice and compliance standpoint, your system should already incorporate:
- Clearly labelled disconnect switches (PV ARRAY, INVERTER, GRID BREAKER)
- Lockable AC/DC switch handles to prevent accidental reconnection
- Weatherproof enclosures for outdoor disconnects (NEMA 3R or better)
- Accessible height and signage compliant with CSA Z462 and local fire code
- Single-point grounding topology to prevent ground loops
Make sure all family members know the location of the PV system disconnect, the main panel solar breaker, and the utility shutoff.
What Happens After Disconnecting Your Residential Solar System
Once disconnected, your system ceases to export power to the grid. If your panels are exposed to sunlight, they may still produce open-circuit DC voltage at the terminals. Depending on the inverter design, your monitoring system may also go offline.
Systems with module-level power electronics (MLPE) or rapid shutdown features may automatically reduce voltage to safe levels (e.g., <30V within 10 seconds per NEC 690.12), but this depends on system configuration.
Once your system is shut down, do not attempt to restart it yourself. Contact a solar contractor from MAG Solar to inspect your equipment, confirm safe operating conditions, and guide you through a proper restart.
