Fluctuating high and low voltages that often precede power outages can damage PCs. This post will explain why a PC might not work after a power outage and what you can do to protect it from any future damage from the opinion of an electrician.
Firstly, let’s be clear. A power outage by itself isn’t what causes damage to a PC. Instead it is the unstable conditions such as fluctuating high and low voltages and even fluctuating frequency that precede a power outage that does the damage.
A PC is plugged into a power outlet which provides a steady voltage. This is either 120 volts at 60 Hertz (USA) or 230 volts at 50 hertz UKAus/NZ).
This is the voltage that many single phase appliances and fittings need to function correctly.
Although a PC doesn’t run on 240 volts (it runs on a much lower voltage via a transformer), it needs this standard input at the power outlet to work properly.
Problems begin to happen when the voltages and frequencies start to change as a result of a fault with the electricity supply which I will talk about below.
Power Outage Damaging A PC – Cause #1
High Voltages
A momentary high voltage over 240 volts will cause damage to a PC.
A PC has circuit boards containing many small electronic components such as capacitors, inductors and semiconductors.These components in particular that don’t like being exposed to high voltages and will begin to fail resulting in the computer not working.
Preventing high voltages from destroying your computer can be done with a surge protector which I will talk about in more detail below.
Essentially a surge protector will send high voltages to earth in the event of a ‘surge’ thereby protecting your computer.
Power Outage Damaging A PC – Cause #2
Low Voltages
Although not quite as damaging as high voltages, low voltages can still cause problems. Low voltages can cause certain electronic components to work overtime to compensate. This results in them either burning them out or failing otherwise.
Power Outage Damaging A PC – Cause #3
Fluctuating Frequency
A momentary change in frequency can damage a PC. For the USA the frequency is 60 hertz (Hz), for NZ and AUS the frequency is 50 Hz. This is the frequency found at every power outlet and any power source using AC electricity.
Frequencies need to be kept constant otherwise lots of damage can be caused to appliances and equipment.
As frequency changes, resistance in the circuit changes. This causes more current to flow. This generates heat which will burn out components in the computer.
This type of ‘outage’ would be quite rare although possible.
How To Protect PC From Power Outage
There are two solutions to protecting your PC. Firstly, install a surge protector in your switchboard. A surge protector in your switchboard will protect all appliances and equipment in your home from an outage. It works by taking high voltages and diverting them away from an appliance and instead sending the high voltage to earth via your earth wire in the switchboard.
Typically, a surge protector will need to be replaced after being used. It will have a color coded indicator showing its status. A green indicator shows that the surge protector is working. A red indicator means it needs to be replaced.
You can purchase surge protector multi boards which will work in the same way and will protect all appliances plugged into it. This is a cheaper way to protect your computer but it will protect fewer appliances in the event of an outage.
Secondly, you can install a UPS which stands for ‘uninterruptible power supply’.
There are many different types of UPS but they basically contain a battery and inverter which is designed to protect electronic equipment in the event of an outage and provide enough time for computers to shut down properly via the internal battery.
While a UPS is more expensive than a surge protector it is a good investment in protecting your computer.
Electricians Perspective
Momentary high voltages before a power outage are the most common reason for damage to a PC in my opinion. Damage isn’t limited to a computer. Any equipment containing electronics will be affected by high voltages.
This could include your oven, microwave, fridge, dishwasher, dryer, TV, LED lights and the list goes on. Pretty much everything has electronics in it. For this reason, it is wise to get a surge protector installed or at least get one for the computer only.
We Fix Faults is an electrician blog dedicated to finding and resolving electrical faults around the home. If you have any topics you would like us to cover send us a message above.