An inverter system being connected to the home's electrical supply

January 4, 2026

How to Connect Solar Inverter: A Detailed Wiring Guide

Wiring solar inverters isn't rocket science, but it can be shocking—literally! The secret? Always connect the battery and DC inputs first, then the AC output. Get this order wrong, and you might fry your gear.

Read on for the step-by-step guide to keeping your eyebrows intact!

Disclaimer: This guide is for educational purposes only. Electrical work is dangerous. Always check local building codes, obtain permits, and ensure you are compliant with regulations. We strongly recommend consulting a licensed electrician. Don't risk your life to save a few bucks.

Understanding Your Connection Points: DC Input and AC Output

Before you start twisting wires together, take a look at the bottom of your inverter. It probably looks like a confusing mess of terminals, but it is actually quite simple. You are essentially playing "match the shape."

Your inverter is just a bridge between two worlds: the DC World (Direct Current) and the AC World (Alternating Current).

The DC Side (Input): This is where the raw power comes in. You will see terminals marked PV+ / PV- (for the solar panels) and BAT+ / BAT- (for the battery bank). These use heavy-duty bolts because DC power requires thick cables.
The AC Side (Output): This is where the usable power goes out to your house. You will see terminals marked L (Line), N (Neutral), and G (Ground). This is what feeds your toaster and TV.

Pro Tip: Never mix these up. Feeding AC power into a DC terminal is a guaranteed way to see "magic smoke" and ruin your warranty.

An inverter connection terminal with red, black, white, and green wiring

Connecting the Solar Panel Array (PV In)

The wires coming from your solar panels usually end in plastic clips called MC4 Connectors. One is Male, and one is Female.

However, you can't just plug them directly into the inverter.

Most inverters use screw terminals, not MC4 plugs. This means you will likely need to cut the connector off the end of your home run wire to expose the bare copper.

Strip the Wire: Expose about half an inch of copper.
Check Polarity: Use your multimeter! Put the red probe on one wire and black on the other.
Read the Screen: If you see a positive number, Red is Positive. If you see a negative number, Red is actually Negative. Never trust the color of the insulation alone.
Torque it Down: Slide the wire into the PV+ and PV- terminals and crank that screw down tight. A loose connection here creates heat, which starts fires.

Connecting to the Battery Bank (Batt In)

Note: In most systems, you should actually do this step before connecting the solar panels so the inverter has power to wake up its brain.

Connecting the battery is the most nerve-wracking part for beginners because of "The Spark."

Inverters have large capacitors inside. When you first touch the battery cable to the inverter terminal, electricity rushes in to fill those capacitors. ZAP! You will get a loud pop and a bright blue spark.

A homeowner creates a spark from mismatching a wire connection

Don't panic. It’s normal. (Pro tip: You can use a "pre-charge resistor" to avoid this, but most DIYers just brace themselves).

Use Thick Cables: Battery voltage is low (12V or 48V), which means the amperage is huge. You need thick cables (like 4 AWG or 2 AWG) to carry that current without melting.
Red to Red, Black to Black: Connect the Positive (+) cable to the inverter first, then the Negative (-).
Tighten Hard: These connections must be rock solid. Vibration can loosen them over time, so give them a serious crank with your wrench.

Connecting to the Main Breaker Panel (Grid/Load Out)

Now we move to the dangerous side—the AC Grid.

This connection allows your inverter to power your home's circuits. This requires running wire from the inverter's AC Output into a breaker on your main electrical panel.

Safety First: Turn off your Main Breaker. The entire panel should be dead. Verify it with a multimeter.

Match the Wires:
- L (Line/Hot): Usually the Black or Red wire. This carries the power.
- N (Neutral): The White wire. This completes the circuit.
- G (Ground): Green or bare copper. This is for safety.
Connect to the Breaker: The "Hot" wire goes into a dedicated circuit breaker in your panel. The White and Green wires go to their respective bus bars in the back of the panel.
Double Check: Tug on every wire. If it comes loose, it wasn't tight enough.

Initial Setup: Configuring Voltage and WiFi Monitoring

Congratulations! The wiring is done. Now, you have to tell the machine what to do.

Flip the "ON" switch. The screen should light up (powered by the battery).

Set Battery Type: This is the most critical setting. If you have Lithium batteries, select "User" or "Lithium." If you use lead-acid settings on a lithium battery, you might damage your expensive storage.
Set Output Voltage: Ensure the inverter is set to output 120V (for US) or 230V (for Europe).
Connect WiFi: Most modern inverters come with a dongle. Plug it in, download the app (like SmartEss or Solarman), and scan the QR code.
Enjoy: Watch the graph on your phone as your roof starts powering your fridge!