How To Protect Home Appliances From Low Voltage (Philippines)

Most home appliances in the Philippines are designed to work on an electrical supply of 230V at 60Hz. However, the electrical supply in some areas can suffer from consistently low voltage – especially in rural areas. Due to the under-development of the electrical infrastructure in these areas, the supply of power cannot meet the demand. Hence, households experience power sags and low voltage.

Excess voltage (otherwise known as a power surge) is – unsurprisingly – harmful to appliances. Surely a deficit in voltage is harmless? It turns out, it isn’t. Low voltage fluctuations can severely damage some appliances, and may even cause a fire; which is why investing in low voltage protection equipment is a wise decision.

Let’s dig deeper and explain what low voltage is, why it happens, and how it affects appliances. We will also get in to why low voltage protection is important, and the different low voltage protection devices for your appliance you can get.

What are low voltage fluctuations?

Low voltage fluctuations can be classified by how long the fluctuations last. A power sag is a short-duration low voltage fluctuation that decreases the voltage significantly below the standard level. Meanwhile, undervoltage is basically a longer-duration power sag. Instead of occurring in a duration of nanoseconds, low voltage events lasts for minutes up to days.

In the Philippines, the standard voltage is 220V at a frequency of 60Hz, and appliances are designed according to this standard. However, most appliances are rated at ±10% 230V, which means that they can work between 207V to 253V. Anything lower than 207V can potentially damage your appliances.

Note: in other countries, low voltage events are usually known as “brownouts”. However, in the Philippines, brownouts and blackouts/power outages have the same meaning.

How do low voltage fluctuations happen?

Low voltage fluctuations can happen on the side of the power provider or on the side of the end-user.

1. High-powered appliances turning on

Appliances that draw a lot of power (i.e. refrigerators and aircons) can momentarily increase demand. If the supply is not there to meet the sudden demand, it may cause a low voltage fluctuation.

In the Philippines, this usually happens during the summer season, when a lot of households turn on their air conditioners to beat the heat.

2. Living in an industrial area

If you live in an area with a lot of factories, their equipment can draw a lot of power when the work hours start. This can also be the case for areas near malls and big office buildings.

3. Living in an underdeveloped area

Areas with an underdeveloped electrical infrastructure can suffer from low voltage fluctuations as the power provider’s supply cannot meet the demand of the customers.

How does low voltage affect home appliances?

You’ll know when a low voltage fluctuation happens when the lights start flickering – but its effects doesn’t stop there. Not all appliances gets damaged by low voltage fluctuations. However, appliances with motors are especially susceptible.

Appliances that have motors or compressors (i.e. refrigerators and aircons) need to maintain a level of torque to work. A higher voltage will increase torque, while a reduced voltage will reduce the torque of a motor.If the torque decreases to a certain level, it will stall the motor. However, power will still be supplied to the motor. Hence the motor will not move, but heat will still be produced.

If this heat continues to build up, it can melt the insulation wires and other parts of your appliance, making them less efficient in the long run. It can also totally destroy your appliance or start a fire if you do not invest in a low voltage protection device.

What appliances need protection from low voltage fluctuations?

As stated earlier, appliances with motors and compressors are the worst affected by low voltage fluctuations. Hence, refrigerators and air conditioners need low voltage protection devices the most.

However, these devices can be costly, and it may not be cost-effective to equip every one of your appliances with these. As a rule-of-thumb, the more expensive your model is, the more it will make sense to equip it with a low voltage protection device.

Due to their more affordable cost, other appliances with motors like fans and semi-automatic washing can get away with not having a low voltage protection device.

The different low voltage protection devices for home appliances

There are several low voltage protection devices that are available in the market. Each type differs in price point and in the level of protection. Here are the most common ones:

Voltage protector (surge protector)

power surge protector for appliance

Voltage protectors are more commonly called surge protectors because they shut off the power supply to the appliance when it unusually high voltage fluctuations. However, they will also shut down your appliance when low voltage fluctuations are detected.

The voltage protector is a must if you live in an area with nearby malls or factories. It is also quite inexpensive and easy to use. However, this protection may not be enough if you live in an area with a consistently low voltage supply.

Automatic voltage regulator (AVR)


An automatic voltage regulator (AVR) is a power protection device that maintains the voltage at the desired level supplied to your appliance, by regulating any voltage fluctuations (both power surges and low voltage fluctuations) that might occur.

This device offers the most protection for your appliance. Some models even come with a built-in surge protector and power-on-delay functions. They are quite pricey though!

How to protect home appliances from low voltage and power sags

Doing these best practices will save your appliances from the brunt of low voltage fluctuations.

1. Do not overload circuits

Plugging in too many appliance into one circuit will make it draw more power than it could handle. This could either cause a power surge, unevenly distribute the voltage to the appliances plugged into the circuit

2. Unplug appliances during or after a low voltage fluctuation

Unplugging your appliances during a low voltage fluctuation can be an easy way to protect them. However, these fluctuations can run its course for a short moment, and you may not be able to get into the crucial appliances in time.

However, it is still a good safety measure to unplug these appliances after a low voltage fluctuation to make sure that they are not stalled.

Of course, some appliances – due to want or need – can’t be unplugged. Refrigerators need to be plugged in as they need to keep your food fresh, which is why those appliances are recommended to be equipped with power protection devices.

3. Inspect your wiring

Regularly inspect your house wiring and your appliance’s wiring as damaged or exposed wires disrupt the flow of electrical current which increases the chance of having a power surge or a power sag.

Some signs that your wiring is damaged are burn marks or burning smells coming from outlets, buzzing sounds, and frequent tripping of breakers.


Low voltage fluctuations are almost ubiquitous in the rural Philippines, hence investing in low voltage protection devices are a must if you want to protect your hard-earned investment on appliances from turning into metallic junk.

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