Why my inverter makes noise

Unusual sounds from your inverter is a cause for alarm. If you are like me, thoughts of an impending fire or explosion immediately come to mind when you hear them.

These noises can be a sign of a fault about to happen, one that could destroy your inverter or even cause a fire or just an annoying sound that does not affect the performance of the inverter.

So, in this post, we’ll walk through the common inverter noises, what causes them and how they can be fixed.

1. Loud hum | vibrating sound from the inverter

Some appliances when connected to an inverter cause a loud hum or vibrating sound in the inverter. It sounds like the inverter is under strain even when the connected appliance’s power consumption is within the inverter’s capacity.

Examples of appliances that may cause this are:

hair straightener

bean to cup machines
hair dryers
dimmable light bulbs

The vibrating sound is caused by interference these appliance create when they process the inverter output power that is then picked up by the inverter.

Whereas this can be a scary and irritating sound, I am not aware of any inverters failures that have resulted from it.

2. Repeated clicking sound in the inverter

Sometimes you may experience loud/ repeated clicks in the inverter instead of the expected hardly audible single click when the Automatic Transfer Switch of the inverter/charger switches from grid power to inverter and back for example.

This repeated click maybe a result of:

in the case of solar inverters, not high enough solar PV voltage for the inverter to switch to the grid. So, you experience the repeated click until the solar voltage is high enough.
or a failing relay in the inverter.

In both cases, it is best to consult the inverter customer support to confirm whether it is expected or a fault.

3. Noisy sound heard when the inverter fan runs

A noisy sound from the inverter may be heard when the fan kicks in. This may be caused o a dusty/clogged fan not rotating freely or a fan that is about to fail.

When this happens:

check the fan and clear any debris, making sure it can rotate smoothly.
If this noise persists, consider replacing the fan. If not possible, then quite likely the inverter needs to be replaced.
If your inverter is still under warranty, then you need to turn it in otherwise
you may have to go to take it to a local authorized repair center.

4. Loud constant buzzing sound in inverter

Sometimes you have a constant buzzing or vibrating sound regardless of whether an appliance is connected or not. This is usually in inverters with large transformers that have been in service for sometime.

The inverter/charger will still work well in spite of the sound likely caused by a lose vibrating transformer plate(s). Should this happen, contact the inverter support if the unit is still under warranty or a reputable local repair service center.

5. Constant inverter fan hum

Whereas it is expected for inverter fans to run occasionally, you may find the contact hum annoying.

Here are 3 tips for controlling the inverter fan hum that have worked for me.

3 Easy ways to control inverter fan hum

# 1. Choose the installation location of your inverter carefully. Try to install the inverter away from places where you need peace and quiet. Some good locations to try first in a home are the pantry, garage, shed.

Also installing the inverter in a location with good air circulation can help reduce how often the inverter fan runs. In particular, always follow the manufacturer recommendations for spacing around the vents.

# 2. Buy an inverter with a low noise level. Always look out for silent inverters when buying one. Ask about fanless inverters. Morning star is a reputable brand and has a 300W fanless inverter.

Stay clear of inverters whose fans runs constantly. Preferably, get one with a variable speed fan.The fans for these ones only come as the internal temperature increases or the inverter hits 50%+ of its rated load.

# 3. Maintain the inverter. One likely cause of inverter fan coming on constantly is the build-up of the dust in the inverter itself.

From time to time, use an electric blower to blow out any dust that may have built up in the inverter. If your inverter needs to be opened to remove the dust build up, you can take it for a blow out at an authorized service center if under warranty.