Fluctuating voltages, frequencies and a lost incoming feed (lost phase) are all reasons why a garage door won’t work after a power outage.
Normally, a power outage by itself won’t damage a garage door.
It is the unstable conditions caused by a fault on the electrical network (especially high voltages) that cause damage to the components inside the garage door unit.
If you want to know what caused the outage then seek more information from the company that manages the power lines and network.
This post will give you some perspective on why the garage door isn’t working from the perspective of an electrician.
Garage Door Unit Wiring & Fault Finding
The garage door unit typically contains low voltage electronics for receiving signals from the remote control.
It also has a motor which moves the garage door up and down.
The garage door unit should also have a manual opening cord which can be used to open and close the door when the unit isn’t working, such as when there is an outage.
The garage door unit is typically plugged into or hard wired into a power circuit. This is usually a power socket.
This power circuit goes back to the switchboard where it is powered by the incoming power feed.
This incoming power feed is a where problems can occur.
Normally, the incoming power should be at a standard voltage and frequency (110 volts, 60 Hz USA, 230 volts, 50 Hz elsewhere). This is what the garage door unit is designed to handle depending on your country.
When this voltage or frequency deviates appliances cant handle it and they begin to fail as I will explain.
In the switchboard the power circuit for the garage door unit should be protected against short circuits and overloads via a miniature circuit breaker.
The garage door should also be protected with an RCD to protect people from electric shocks. MCBs and RCDs can’t protect your appliances from unstable incoming power issues. This is what a surge protector is designed to do which I will discuss below.
With this in mind, let’s look at what can go wrong when there is a power outage.
Garage Door Not Working After A Power Outage? – Reason #1
High Voltage Fluctuation
Likelihood: High – a common occurrence in my experience. Call your power lines network company to confirm the cause of the fault.
Fixable? No, the garage door unit probably isn’t fixable. The electronics in the unit and the motor bringing the door up and down don’t like high voltages.
High voltage can cause a lot of damage to garage door units, even if exposed for only a moment. A high voltage is anything above 110 volts in the USA and 230 volts in AUS/NZ/UK.
Garage Door Electronics
A high voltage will cause the electronics in the garage door unit to short out and go bang.
The electronic components most likely to go bang are capacitors which have strictly defined voltage limits.
When this limit is exceeded they short out and fail. Many other electronic components such as semiconductors can short out with high voltage.
You might be able to see evidence of this with black sooty spots around or inside the garage door unit indicating this has happened.
Garage Door Motor
The motor for the garage door contains windings which produce the work that brings the door up and down. These windings are insulated according to the voltage it’s designed to operate at. As mentioned earlier this is a standardized voltage which is normally constant. When this voltage is exceeded the motor windings can short out causing the motor to fail and not work.
The garage door motor also likely has capacitors which also will fail with high voltage.
Garage Door Not Working After A Power Outage? – Reason #2
Abnormal Frequency
Likelihood: Possible – depending on what caused the fault. Call your lines company for clarification on what caused the fault.
Fixable? No, the garage door units electronics will burn out if the frequency changes.
If a fault on the power lines network has altered the frequency, even temporarily, it can cause problems for your garage door unit.
Essentially, when the frequency changes (it should be 60 Hz USA and 50 Hz UK/AUS/NZ) it results in more resistance in the circuit. This leads to more current being drawn by components, burning them out if they are not rated to handle it.
Electronic components are susceptible to this.
Garage Door Not Working After A Power Outage? – Reason #3
Lost Incoming Feed (Lost Phase)
Likelihood: High – if your property is on three phase power.
Fixable? Yes, waiting for the lost feed to come back online should fix it. Contact your local lines company.
This section is only relevant if you are on three phase power. Basically, the garage door unit might be on a phase that is still offline. There might be other circuits in the home that are also still offline. Waiting for the phase to come back online should fix the problem.
Install A Surge Protector
A surge protector will protect your appliances in the event of unstable network conditions. It does this by diverting high voltages away from appliances and to your earthing system therefore saving them. A surge protector is a very good investment if you have a lot of electronics in the home which everyone does. Almost everything has some electronics including the internet, computers, even microwaves, ovens and fridges.
Electricians Perspective
A high voltage fluctuation damaging the electronics and motor inside the garage door unit is the most likely reason it isn’t working after an outage.
If this has happened the most likely solution is to replace although discuss with the manufacturer what your options are.
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