The amount of amps that a refrigerator will use depends on how you configure your electrical installations and how much extra load you place on the electrical breaker.
It doesn’t matter if your fridge is a household appliance, industrial, or installed in a campervan.
If you overload an electric circuit, it will cause a breaker to flip, or a fuse might blow.
It can also short the circuit, which can cause lots of other problems, such as damaged appliances and even fires.
According to the US Department of Energy, most refrigerators need between 15 and 20 amps and around 700 watts of energy.
This value will depend on the voltage of the fridge, where the fridge is, how old it is, how you use it, how many cubic feet it takes up, and what you set the temperature as.
If you doubt your RV’s battery will be able to power your refrigerator, consider getting a propane generator: 5 Best & Most Efficient Propane Generators (in 2022).
How many amps does a refrigerator use?
This will depend mostly on the size of the fridge. Larger refrigerators can cool more but need bigger compressors to be able to do that.
The compressor is the part of the appliance that uses the most power. Another big consumer of electricity is the fridge’s light bulb. This is usually a standard 40W bulb, so it doesn’t affect the variation much.
Most domestic fridges are rated inside the range between 3 and 6 amps, but this range can change to between 1 and 15 amps, depending on the size of the fridge and how much power the compressor consumes.
If you know the wattage of your refrigerator, you can easily calculate its amperage. Just divide the amperage with the voltage you have. However, it can be hard to know the wattage of your refrigerator.
Manufacturers usually don’t state the wattage in the documentation of your fridge, and they will instead share figures of annual power consumption, which can be quite misleading.
When manufacturers state the wattage, they usually provide the startup wattage, which is determined by the locked rotor amperage of the compressor, which is a lot higher than the current the fridge will use continuously, most of the time.
How many amps does a refrigerator use on startup?
Startup amps are different to running amps. Some appliances need more power to start. On average, most fridges use around 15 amps to start.
Refrigerators have a starting wattage of around 800 to 1200 watt-hours/day, and a running wattage of around 150-watt hours/day.
How many amps does a mini fridge use?
Most mini fridges will need around 2 amps to run. They also consume between 80 to 100 watts per hour while they are running.
Fridges work by pulling the heat out from their insides. This is done through special liquids and gasses that are used inside the refrigerator.
The liquids in the fridge will boil at very low temperatures that are well below freezing point. This is what lets their state be changed by manipulating their pressure.
The compressor in the fridge is what does this. The role of the compressor is to increase the pressure of the coolant and turn it into a liquid.
The coolant can then flow through the cooling elements, where it becomes exposed to temperatures that are above its boiling point and it draws thermal energy from the environment and turns into a gas. However, this cycling is not happening all the time.
Fridges cycle their compressor on and off. You might be able to hear this happening. Sometimes, you can hear your fridge buzzing, while at other times, it will run silently.
You’re noticing this noise because the compressor is generating heat, and needs to take an occasional break to allow itself to cool off.
The on cycle length will be different for different fridges, even between different models from the same manufacturer.
Older fridges used to have on cycles on around 30 to 40 minutes, with 6 to 9 hours in an off cycle. Newer options have on cycles of between 4 and 8 hours, with off cycles of only thirty minutes.
As your fridge is not consuming power all the time, if you know it’s annual power consumption, you won’t be able to precisely calculate its amperage unless you know exactly how and when these cycles are coming on.
Another issue with these on and off cycles is they depend on the conditions of where the fridge is being kept, how often you open and close the fridge and the temperature of the things you put inside it.
This is why you will often see two amperage ratings on the sticker on the compressor; a rated current and LRA or locked rotor amperage.
The rated current is the maximum amperage at which the compressor in your fridge will operate continuously.
To put it simply, this is the amperage for most part of the on-cycle on the maximum load. Your fridge will draw this amperage when it is turned right up to its maximum setting. If isn’t at this setting, it will draw a lower amperage.
Normally, the compressor in your fridge will not go above this value. However, it is supplied by a much lower voltage than it is rated for, it can happen. If this is allowed to happen, the components of the electric motor in the compressor can go wrong and fail.
Locked rotor amperage
When a compressor is starting up at the beginning of it’s on cycle, it will be experiencing some internal resistance. This resistance is both electromagnetic and mechanical, due to the inertia of the coolant that the compressor is trying to move.
This is solved by increasing the amperage for the first few seconds of its on cycle in order to overcome the resistance.
This higher amperage is called a startup, locked rotor amperage, and sometimes is called a surge current.
Depending on what fridge you have, this surge current is usually around 2 to 3 times the rated current. However, in some older fridges, it can get up to 5 times more than the rated current.