What is a supply voltage switch? How to adjust it

Your PSU can adapt to different power options much faster than you think. Because companies sell their equipment to many other people in many different places, they often include options to bridge the differences in how those people use it. It might be harder to sell to various groups if they don’t. A perfect example is the supply voltage switch on the back of your power supply.

What is a voltage switch?

If you look at the back of your power supply, you might be surprised to see two switches on the back. One of them is the power supply disconnect switch that you have to use almost every time you turn off the power to the computer. It’s not the voltage switch, though.

The voltage switch is a separate switch that changes the voltage the power supply operates with. You can switch it between 110/115V and 220/230V. What you choose depends on the type of energy used by your country. You must select the correct voltage to ensure proper power flow through your power supply and components.

How do I know which option to choose?

You will need to check which voltage is standard in your country. Some countries also have more than one voltage, so you need to check the outlet and understand which one you are using.

Since voltage switches are usually only on desktop power supplies, you shouldn’t have to adjust them very often. If you are traveling with your computer or moving to a new country, check the voltage you will be using before turning on your PC.

What if I don’t see a voltage switch?


Not all power supplies have a voltage switch, but that doesn’t mean they can’t adapt to the voltage standards of different countries. It all depends on what your particular unit is capable of.

Some power supplies can detect incoming voltage and automatically adjust to match the available current. This is an internal process that does not require you to set a switch type or make any software changes. The power supply itself can tell if it is receiving one voltage versus another and can work with both, providing the correct type of power supply.

Some power supplies are only designed to work with one type of voltage. If so, you will need to get a new power supply or use a converter strip if you have one available.

If you’re not sure if your power supply can fail over automatically, there are several ways to find out.

  • Check the packaging: Most of the time, the necessary information will be printed on the PSU box so that a buyer understands in advance what they are buying. Generally, you can use a power supply in the country where you bought it, but you should always check before plugging it in if you’re not entirely sure.
  • Read the manual: Many of us are guilty of throwing computer component manuals into a drawer soon after purchase. However, they contain a lot of information that you may not realize you need long after you put them away. Go through it and look for any information regarding voltage.
  • Read information online: If you no longer have the packaging and the manual, read the information online. Whether you check the manufacturer’s website or a sales listing, you may be able to find out what kind of voltage switching options it offers, if any.
  • Contact the manufacturer and discuss: If you can’t find any other information and don’t see a switch, you may need to find out if it can be automatically converted directly from the source. However, if nothing you read says it can switch between voltages, the best guess is that it will only work on the standard voltage listed.

How can I change the voltage of my power supply?

It’s actually simple to do. Look at your voltage switch and read what the label says. This label is the setting it is currently on. If it reads 115V, then it is set to 110/115V. If it reads 130V then it is set to 120/130V.

change voltage

If you want to switch to the other setting, you need to slide the switch so that the other label is displayed. Once the voltage label matches the voltage of your outlets, you are ready.

Always make sure the computer is turned off and you have turned off the power switch on the power supply. Also unplug the computer from the wall. You don’t want to flip the power switch while it’s plugged in, or it could damage your computer. It is not designed to switch from one setting to another during use.

What happens if I run the power supply at the wrong voltage?

One of two things that can happen if you try to run the power supply with a voltage that doesn’t match the current of the wall outlet.

First, the computer may not turn on at all. If the power supply is not receiving enough voltage or detects a problem with the current, your computer may simply not boot. In this case, nothing would be damaged, but nothing would be usable.

Then the computer may turn on, but you may end up with damaged components. They are intended to work with a specific type of power flow. If the PSU isn’t supplying power properly, it can degrade your expensive internal components, such as the motherboard, processor, and RAM.


For these reasons, it is essential to operate your power supply at the correct voltage at all times. Look for a light switch and read the manual before turning it on if you are unsure. Even if this means installing a new power supply, do not attempt to operate your computer with the power supply set to the wrong voltage.

What if I bought a pre-built computer?

pre-built pc

It all depends on the parts that the manufacturer puts in the computer. For example, you may not be able to access the buttons on the power supply from outside the case, especially if it is custom designed for this model. The best thing to do is check the manual and ask the manufacturer if it’s designed for the one you’ll be using now, especially if you’re not sure.

If you want to buy a computer from a manufacturer that doesn’t include voltage information, and you’re not sure if the included power supply would work for the country you’re in, talk to them before you buy. . They may have an option available for people in the country of your choice.

What voltage am I most likely to use?

In general, you can expect to use the lower voltage if you live in the United States and the higher voltage in other countries. However, this is not universal and does not apply to every wall outlet. Consult a guide before using your power supply.

Frequently Asked Questions

What if I can’t move the switch?

If there’s a switch, but it won’t move, you’ll probably need to use more force. Some experts recommend using a push tool to give yourself more leverage and force the switch to the other option. If you still can’t get it, contact the manufacturer for help. You don’t want to break it in the process.

What if I don’t have the correct voltage for my country?

You can usually find an AC adapter that converts to one compatible with your power supply. Check the instructions on any converters you find and make sure they have the correct plug style for your power supply cord. The best way to get an adapter is to get it before you need it – they’re usually small and make a great addition to your luggage before a trip or move.

Should I buy a power supply with a voltage switch even if I don’t plan to travel?

You don’t have to, but it will prepare you for anything that might happen. If you are sure not to travel. However, many high end power supplies will include voltage switching capabilities. You don’t want to buy the cheapest power supply you can find, especially if you’re building a high-end computer.

You want something that delivers consistent, uninterrupted power and is designed to perform well under heavy loads. Most of them will have some sort of feature or switch that lets you change the voltage, assuming it doesn’t do it automatically.

Alan A. Seibert