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So your inverter is humming along fine, then one day it just shuts off. Even worse, it keeps shutting and restarting. Is the inverter damaged? Did you do something wrong? No need to panic. In this guide we will explain why this happens and what you can do about it.
If an inverter keeps shutting off it is often for safety reasons. This can occur if the voltage level is too high and the inverter cable is not thick enough to handle the incoming power. Other possible reasons are incorrect parameters, lack of power and damaged circuits.
Let us take a look at the most common reasons why an inverter will shut down or restart over and over.
1. Voltage is Too High
The most likely reason is the voltage level is above the acceptable level. No matter what the inverter size is , these systems have a certain voltage limit. When the limit is reached the safety trigger mechanism kicks in.
There are many reasons why the voltage level would spike. Most likely it is already above 240 volts or the inverter phase is set to the limit already. The operating manual includes information on the maximum voltage limit, so make sure this is not exceeded.
It is true that thicker cable wires cost more, but you will get your money back in terms of performance. if you want to run high powered appliances and devies off an inverter, get the thickest wires compatible with your inverter.
2. Inverter Cable Size is Incorrect
Just like solar panels and batteries, the inverter cable has to be the right size to work. Inverter cables should be as short and thick as possible to provide the best results.
If your inverter draws power from a battery bank, the current has to pass through the cables. Long, thin cable wires produce resistance, and the longer the current has to travel the more power is lost.
With a short thick AWG wire gauge, the inverter loses less power during the conversion process. The loss from lengthy cables might reach the point there is not enough power to start the inverter.
Too much power (high voltage) is bad for the inverter, and so is too little of it. With the right cable wires these problems can be avoided.
You can find information on inverter cable sizes in the manual. While short, thick cables are usually the best, the manufacturer might recommend a specific wire size in mind.
3. Internal System Failure
By system failure this can refer to any part of the solar system, the inverter, solar panel, charge controller or battery bank. Usually if there is a problem the inverter will display an error message, but sometimes it just shuts down.
If there is an error message, refer to your owner’s manual troubleshooting section. You can also reset the inverter or use any of the suggested methods provided here.
If none of these techniques work, the inverter is probably damaged and needs to be fixed by the installer. Contact the manufacturer for help and technical assistance.
4. Insufficient Solar Power
An inverter connected to a solar system depends on the solar panels for power. If there is not enough sunlight, the panels will not be able to produce the electricity required by the inverter to run.
This can happen during cloudy and winter days if your inverter is connected to the solar panels . Once there is enough power available the inverter will run smoothly.
Solar power supply should not be an issue during summer. If you are on the grid you can use electrical power to run the inverter. But if you are off the grid, install a battery bank so the inverter can have a consistent power source.
5. No Grid Power
Solar inverters tied to the grid automatically shut down during a power failure for safety reasons. If there is a power outage in your area or flickers on and off, your inverter will shut down.
Contrary to popular belief, grid tied solar systems cannot run during a blackout. This is because the system has to be turned off to protect utility workers who will fix the power lines.
Your solar system – including the inverter – is connected to the power grid. If it continues to run during a power outage, it will supply electricity to the power lines and put the lives of technicians at risk.
For this reason inverter systems have an automatic shutdown feature. If you want to run a grid tied inverter during a blackout, a battery bank needs to be installed to run essential appliances.
The battery bank size will depend on the inverter capacity and how many appliances you want to run. If you have a 3000 watt inverter for instance, it would take one 12V 250ah battery to run it on a full load for one hour.
Incorrect Inverter Parameters
Inverters can also shut down or restart repeatedly due to incorrect parameters. Each inverter has its own configuration options and settings, and choosing the wrong one can affect performance.
The configurations are set up during installation , and usually it is best to leave them alone unless there is a problem. You can tweak the settings anytime, but selecting the wrong option can cause problems.
For safety reasons, use only the settings recommended by the manufacturer. If you want to try another option, contact the installer to ensure it is safe, at the very least make sure you the manual says it is permissible.
Why is My Inverter Beeping?
An inverter usually beeps for two reasons, its capacity is overloaded or battery power is low. The beep may be continuous or intermittent, but it has the same purpose, sound off the alarm.
If the inverter beeps you should immediately check the capacity. If it is overloaded or close to it, reduce the load as quickly as possible. You do not want an electrical power outlet to get overloaded for obvious reasons, and the same thing applies to inverters.
An overloaded inverter might also exhibit the shut down / restarting signs mentioned above. Because the capacity is full, the safety mechanism goes off, shutting the system down.
If the load is within capacity, the beeping is due to to low battery power. Recharge the battery as soon as possible and when there is enough power the beeping will cease.
Deep cycle batteries like FLA, AGM and gel should not be fully discharged. When the capacity reaches 50% the battery has to be recharged. Keep this in mind if you have a solar system and the inverter relies on the batteries to generate power.
If you want to keep the inverter running continuously, the battery bank must be large enough to keep the system running. Or you must have a solar array that can recharge the batteries so the inverter can keep going.
How Do I Reset My Inverter?
Most inverter glitches and problems go away with a reset. It is similar to rebooting a computer after it crashes. By resetting an inverter it should refresh the system memory and start over.
To reset the inverter, press and hold the on/power button. Lift your finger when the button starts flashing. This might take 10 to 20 seconds depending on the model. Wait until the inverter restarts and then try it again. The problems and error codes should disappear.
What Causes an Inverter to Fail?
There are many reasons why an inverter may suddenly stop working. The following are the most common and applies to most makes and models.
Improper voltage levels. Too much and too little voltage is not good for inverters. If there is too much voltage going into the system, its components will overheat and damage the internal circuits. Overheating is also a problem for solar batteries, hence the need for charge controllers.
Wear and tear. Inverters are designed to run for a specific number of years. Prolonged use will wear out the components and will eventually cease working. Even a well maintained inverter will give out someday.
Excessive heat. Inverters can only run under a specific temperature range. This range will vary per product, but going beyond this will negatively affect performance. Using the inverter in conditions beyond its capacity will also void the warranty.
The inverter is the most sensitive part of a solar system. This is understandable as it is designed to run your appliances. Seeing it shut down suddenly can be scary, but with the tips in this guide you can fix the problem.