A fluctuating voltage or frequency from the incoming feed or a lost electrical feed are possible reasons why a fridge won’t work after a power outage.
It is not the power outage rather the events preceding such as high or low voltages that cause the fridge not to work. This is typically due to a fault on the supply network managed by the local lines company. Fridges are designed to operate at a steady and standardized voltage and frequency. When this changes problems happen as I will explain in the next few sections. This post aims to cover 4 possible reasons why a fridge won’t work after a power outage and whether the fridge is fixable or not from an electrician’s perspective.
Table of Contents
- High Voltage
- Low Voltage
- Fluctuating Frequency
- Lost Phase (Lost Electrical Feed)
- Why A Circuit Breaker Won’t Protect Appliances From A Power Outage?
- Surge Protection
- UPS
- Electricians Perspective
Fridge Wiring & Fault Finding
The electrical components of a fridge relevant to this post include the
- Motor for the refrigerant.
- Electronic components such as the fridge display for newer models.
- Low voltage components such as lights.
- Control components like thermostats.
All of these are susceptible to problems when the incoming voltage and frequency changes.
A fridge is designed to operate at the set voltage and frequency of the country you are in. This is either 120 volts at 60 Hz for America and 230 volts at 50 Hz for UK/AUS/NZ and other places. This is the set voltage and frequency you will find at every powerpoint in your home.
A fridge needs this standardized voltage to work and is connected to it via a plug and cord plugged into a powerpoint.
Here is what can go wrong when there is a power outage.
Fridge Not Working After Power Outage? – Reason #1
High Voltage
Likelihood? High – this happens often in my experience but may differ depending on where you live.
Fixable? No, the fridge most likely can’t be fixed economically. High voltage will fry electronic components, low voltage components and the motor.
High voltage, even for short periods of time, can damage almost every electrical component in the fridge. If the voltage is high enough it can even ‘jump’ out of the insulation and damage other components as well.
High voltage can cause the windings in the fridge motor to ‘short out’ and fail.
High voltages can cause the plates in capacitors to also short out and fail.
A sign of this is burnt, black sooty spots on circuit boards. When something shorts out it can leave weird burnt smells too which is something to look out for.
Fridge Not Working After Power Outage? – Reason #2
Low Voltage
Likelihood? Moderate
Fixable? Check for a tripped breaker in the circuit board. Resetting could resolve the problem.
Low voltages can also cause a lot of problems mainly for the fridge refrigerant motor. A low voltage causes the motor to draw more current before eventually burning the windings out. The motor in this case would need to be replaced. If the fridge has lights and a display but isn’t cooling you might just need the motor replaced and the control circuit checked by an expert in refrigeration.
Fridge Not Working After Power Outage? – Reason #3
Fluctuating Frequency
Likelihood? Moderate
Fixable? Generally not as everything is likely affected.
When the frequency changes from 60Hz or 50Hz it can cause the resistance for all circuits in the fridge to change. This can produce disastrous results. It leads to more current which generates heat burning out components such as the motor and electronics.
Fridge Not Working After Power Outage? – Reason #4
Lost Phase (Lost Electrical Feed)
Likelihood? High if your property is on three phase power.
Fixable? Yes, just wait for the power to come back on. It should resolve.
If your property is on three phase power then it is possible that one phase is still out. This phase obviously has the fridge on it. In this case, just wait for the electrical feed to come back online. Contact your line company to find out when this will likely occur.
Why A Circuit Breaker Won’t Protect Appliances From A Power Outage?
No, circuit breakers won’t protect appliances from a power outage. Circuit breakers (MCBs) will protect cables from short circuit and overloads. RCDs will protect people and equipment from damaging shocks. Neither will save your appliances from high or low voltages caused from power outages. Instead you will need to install either a surge protector or UPS to protect specific equipment.
Power Outage Protection #1
Surge Protection
A surge protector can be installed in the switchboard to protect the appliances in your entire home from high voltages. It does this by sending unusual voltages to earth via your earthing system thereby protecting your home. Having a surge protector is a good investment in avoiding having to buy new appliances. You can also buy surge protector multi boards which can protect whatever is plugged into them.
Power Outage Protection #2
UPS
A UPS will detect when there are unstable voltages and power the fridge off its own battery supply until normal voltages are resumed. A UPS is plugged into a normal power outlet and the fridge would be plugged into the UPS. It stands in the middle of the circuit.
Electricians Perspective
High voltage damaging the fridge is the most likely reason why it isn’t working. As high voltage would likely have destroyed many components, it might not be economical to repair the fridge instead replace it.
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