Inverter Clicking On And Off: The Best Answer On Why

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What is that clicking sound coming from your inverter? And why is your inverter clicking on and off?

An inverter, whether for your solar panel or as an RV inverter, has a safety and start-up sequence that it goes through before it can provide ac power. And with your inverter clicking on and off, something is not 100% right for the inverter to stay on.

The relay switch is the most common cause of an inverter clicking on and off. This post reviews how to diagnose and understand what that clicking is and the fix, including:

  • Noise
  • AC System
  • Voltage
  • Load

As we dive into this issue, let’s first understand what is clicking and why the inverter is doing that.

Table of Contents

Noise

First, what does the clicking sound like? Does it sound like someone has pressed a button on a keyboard? Or like clicking a computer mouse?

What is the frequency of the clicking? Is it every 5 to 10 seconds?

If you answered yes to the above, the likely cause of the clicking is a relay.

A relay is no more than an electronic switch. It powers components in many electrical systems, including air conditioner and cars. For example, when you press a button in your car to turn on your headlights, that button is a low-voltage switch that sends an electromagnetic signal to a relay. That relay has higher voltage wires that then switch on the headlights.

Inverter

Your inverter also has relays. For the inverter to produce ac power, certain requirements must be met. The inverter will cycle through its startup sequence when any requirement is unmet. Let’s go through some of those sequences that can cause the inverter to keep trying to turn on and off.

AC System

The inverter’s main (and only) purpose is to provide AC power from a battery. Whether a generator or solar energy charges that battery, the same principles, and functions apply to the inverter. It takes DC power from a battery (likely a deep cycle battery) and then converts it to AC power to plug in appliances.

I must pause here and make a quick distinction that is a common mistake. An “Inverter” is different than a “Converter.” An “Inverter” takes DC power (from a battery) and converts it to AC Power, such as household appliances. Whereas a “Converter” converts AC Power to DC Power. Think of a “converter” more like just a battery charger.

Voltage

Checking for voltage is the most common cause for the inverter relay to go through its start-up sequence. Since the inverter gets its power from a battery, the battery must provide the voltage needed. Any voltage issue will cause the inverter to go through its sequence, looking for power.

Low Voltage

Check your battery voltage and see what you have.

To check your battery power, you can use a basic multi-meter. Set it to DC Volts and put the black probe on the battery’s negative terminal. And take the red probe and put it on the positive post of the battery terminals. You should have anywhere from 12 volts to just over 13 volts.

This is considered a fully charged deep-cycle battery. If you have less than 12 volts, the battery must be charged.

While there, check the battery cable and terminal for corrosion and a secure connection. Any corrosion can cause a weak metal-to-metal connection and issues with the battery charging or giving the inverter the power it needs.

Solar Panel

Check the panel wiring and control system if you power the batteries with solar panels. Like checking a battery, you can check your solar output to ensure you get enough volts.

Check the solar controller for a secure connection

A solar panel is a battery charger that gets power from the sun. And to charge a battery, you need a higher voltage for the battery to take a charge. Usually, a solar panel will provide over 14 volts of power to charge a 12 volt battery. Like the above, check the battery’s voltage and the incoming solar power. If you get 12V or below, the battery is discharged and will cause the inverter to keep looking for the proper voltage.

Load

Another potential cause of the inverter clicking on and off is the load. The load is the watts or devices connected to your inverter, such as an appliance. All inverters are rated by watts. They range from 500 watts to 5,000 watts.

Any overloading of this capacity will cause the inverter to turn off and on as it goes through the start-up sequence.

Check your inverter watt capacity and see if it is overloaded. Motors and higher amp appliances draw more power and can surge, causing the inverter to overload.

If you notice that you have exceeded the watt rating, reduce the items plugged in and see if that resolves your inverter issue of clicking on and off.

Final Thoughts

A relay is the most common cause of an inverter clicking on and off. Low voltage from the battery or power overloading will cause the inverter to cycle through its start-up sequence, causing the relay to make a clicking noise.