People assume that an uninterruptible power supply (UPS) can provide backup power to any device or appliance. In most cases, they’re right. However, appliances like refrigerators have unique power consumption patterns that make them challenging to use with a UPS.
Yes, you can run a fridge on a UPS battery backup. However, it’s unsafe to use consumer-grade UPS models more suited for smaller electronic devices. The refrigerator compressor causes a significant current spike when it turns on, which can easily overload a standard UPS. That’s why you’ll need an industrial or specialized UPS to power your refrigerator during a power outage.
Finding a UPS to use with your refrigerator is challenging but not impossible. This guide will give you all the necessary information to make that possible.
Can A UPS Be Used For A Refrigerator?
Yes, you can use a UPS battery backup to run a refrigerator for short periods during a power outage.
Unfortunately, you can’t do that with consumer-grade UPS models that most people use at home or in offices. Due to the current spikes caused by a fridge’s compressor, you would need an industrial-grade or specially built UPS to work safely with your refrigerator.
How Does A UPS Normally Work?
Remember: an uninterruptible power supply (UPS) is typically used to provide backup power to electronic devices like computers and servers during a blackout. When the incoming voltage drops too low or there’s no power, the UPS battery will take over and supply power to connected devices.
Small electronic devices like computers and laptops don’t draw much electrical current. That’s why a consumer-grade UPS has no problems powering several of them simultaneously.
Sadly, that’s not the case when it comes to refrigerators that have power-hungry compressors in them.
What Happens If You Use A UPS With A Refrigerator?
When you run a refrigerator on a UPS, there’s a high chance of overloading the backup battery. That will cause damage to the UPS internal circuits and their batteries.
Refrigerators rely on compressors to keep their compartments cold and protect your food items inside. Those compressors typically run for short periods to lower temperatures in the compartments and shut off when the desired temperature has been reached.
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When a compressor turns on, it draws an extremely high electrical current known as an inrush current, a switch-on current, or an input surge current.
No matter what you call it, that initial current spike is much higher than what most consumer-grade UPS models can handle.
As a result, the UPS quickly becomes overloaded.
What Happens If I Overload A UPS?
A UPS overload is when devices or appliances draw much more current than the battery backup can provide. They can happen slowly, like with small electronics, or quickly, like with a refrigerator compressor.
Suppose you plug a fridge into your UPS, and it overloads. Here’s what will happen:
- Alerts and alarms: Even the most basic UPS model comes with warnings that warn you of an overload condition. Depending on your model, you might see flashing indicators, error messages on a screen, or hear loud beeping noises to tell you the overload is happening.
- Automatic shutdown: UPS units will run for a short period during an overload. If the overload continues, many UPS models will shut themselves off automatically. That’s a way for UPS to protect itself from damage and prevent other electrical problems.
- Electrical damage: Your UPS consists of internal backup batteries and the electronic components that monitor and control them. All of those items can suffer excessive wear and damage from UPS overloading.
How Do I Fix UPS Overload?
Under normal conditions, a UPS overload is very straightforward to fix. You only have to disconnect non-critical devices from the UPS, resolving the issue.
As you might imagine, that’s impossible if you’ve only got a refrigerator plugged into a standard UPS battery backup.
It’s also not practical to keep having to unplug your refrigerator from the UPS every time it overloads.
How Do I Choose A UPS For A Refrigerator?
So far, you’ve seen why a refrigerator can’t be used with a consumer-grade UPS, which people use to protect their electronic devices. However, as mentioned in the introduction, it’s still possible to run find a UPS that can power your fridge during a power outage.
Here’s how you can choose the correct UPS to use with a fridge:
Step 1: How Much Power Does The Fridge Use?
Like any device or appliance you’d plug into a UPS, you must first understand how much power it needs to stay on.
Thankfully, you can find this information quickly on the nameplate that’s attached outside the fridge’s body or inside one of its compartments.
Alternatively, you can find its power consumption specifications in its user manual or by checking the manufacturer’s website.
Step 2: Identify The Startup Amps
As you read earlier, the biggest issue with pairing a UPS and a refrigerator is the current draw when the compressor turns on. Therefore, the UPS you choose must be able to cope with that peak current draw.
Regarding refrigerator compressors, the information you’re looking for is the total startup amps, also known as the Locked Rotor Amps (LRA).
This peak amperage figure can be anywhere from 5-10 times higher than the amps required to keep the fridge running (i.e. the number you found in Step 1).
So, try not to be surprised at the vast difference!
Step 3: Consult UPS Manufacturers
Once you know your fridge’s power usage and startup amperage, you can already shop for a UPS with a higher capacity.
However, it would be wise for you to consult UPS manufacturers directly and seek their advice.
When you provide them with the information from Steps 1; 2, their engineers or support staff can help you choose the most suitable UPS products to power your refrigerator.
More importantly, leading UPS manufacturers like APC and Eaton have specialist UPS products that will work well with medical refrigerators.
Unfortunately, those products aren’t available to consumers to buy off-the-shelf, so you’ll have to consult the manufacturer directly.
Frequently Asked Questions (FAQs)
Here are a few more questions and answers to help you understand your UPS:
How Long Is Food Safe In A Fridge With No Power?
According to the Centers for Disease Control and Prevention (CDC), food can stay safe in an unpowered fridge for 4 hours (and a freezer for 24-48 hours) as long as the doors remain closed.
How Often Should A Fridge Compressor Come On?
A fridge compressor will come on whenever the fridge compartment becomes too warm. That means it’ll turn on every few hours for short periods or more frequently if you’ve set a lower fridge temperature.
Can I Run A Refrigerator On A Generator?
Yes, running a refrigerator on a generator is not only possible but it’s also recommended. In many cases, using a generator to power your fridge during a blackout is more suitable than using a UPS.
Can A UPS Overheat?
Yes, a UPS and its components can overheat. Overheating will cause excess wear and damage to the UPS and its batteries. The unit has indicators and alarms to warn you when it happens. A UPS will also shut itself off if the overheating lasts too long.
How Do I Fix The Beeping Noise In My UPS?
A UPS will beep for several different reasons that you must troubleshoot. Still, all UPS models have a button to mute the beeping. The button differs between brands and models, but they’re labeled with words like ‘mute’ or ‘silent’ or with an icon of a speaker with a line through it.