A fluctuating high or low voltage and an offline electrical feed are reasons why an electric gate won’t work after a power outage.
Often power outages can be preceded by unstable voltages that can fluctuate unusually high or low.
Both of these conditions can create havoc with components inside an electric gate unit, especially the motor, any electronics, and any extra low voltage wiring such as 24 volt systems.
This post aims to explain why the electric gate isn’t working and its fixability from the perspective of an electrician.
Electric Gate Basics And Fault Finding
Depending on the type of electric gate unit installed, it could be a system designed to run at your standard wall socket voltage or on lower voltages such as 24 volts.
Gate units that run on lower voltages are wired with a cable that is appropriate for 24 volts.
If the voltage is exceeded such as during a power surge the insulation on the cable can fail causing damage to the electric gate unit.
The electric gate unit will have a motor which moves the gate open and closed.
This motor can be either 24 volt or standard 120 volt (USA) 230 volt (UK/AUS/NZ). The motor can be controlled by a range of different methods including keypads and electric gate remotes.
Both of these systems involve electronics which are susceptible to voltage fluctuations.
Electric gates are connected to an incoming power supply that may originate from your main switchboard or a sub switchboard located closer to where the gate is.
If the gate is located at the end of a long driveway there may be a sub-switchboard located closer to the gate (perhaps located in the meter box).
This is sometimes done because running a cable from the house to the gate location is too far and impractical
If the electric gate unit is 24 volt it will still have a standard 120 volt (USA) or 230 volt (UK/AUS/NZ) supply except there will be a transformer which reduces the voltage down to 24 volt for the gate to use.
With a basic idea of how an electric gate unit is wired let’s look at what can go wrong after a power outage.
Electric Gate Not Working After Power Outage? – Reason #1
High Voltage
Likelihood: High in our experience especially if the unit is 24 volt or contains electronics. Check what type of unit you have for more information.
Fixable? The gate is probably not fixable if the electronics are fried. Signs of this include burnt or ashy black spots on electronic circuit boards.
An electric gate unit is designed to operate at a standard and steady voltage. When the voltage changes it can cause tremendous damage to components especially electronics and the motor. If the gate unit is low voltage (24 volts) it can damage everything due to the lower insulation rating of the cable compared to the cable used with standard 120/230 volts.
The main susceptible components to high voltage in a gate unit include capacitors, inductors, resistors and semiconductors.
Capacitors in particular operate within a very specific voltage range. When this is exceeded they short out in often spectacular fashion.
This can leave signs such as a metallic smell or burnt and melted areas inside the gate unit (after taking the cover of the unit off).
If high voltage has gotten through your gate unit, you will most likely need to replace it and consider adding a surge protector to your switchboard to protect it in future.
Electric Gate Not Working After Power Outage? – Reason #2
Low Voltage
Likelihood: Moderate – if the gate was used during an unusual voltage event. Contact the company that manages the power lines for more details on the fault.
Fixable? Probably not. The unit may need to be replaced.
If the voltage gets too low (as a result of a fault on the network) then the motor inside the electric gate unit can burn out. This is true for either 120 (USA) volt / 230 volt (UK/NZ/AUS) units and extra low voltage units 24 volts.
When the voltage is too low the motor tries to compensate by drawing more current. This generates too much heat and burns the windings of the motor out. This causes the motor to not function.
Electric Gate Not Working After Power Outage? – Reason #3
Lost Phase (Offline Electrical Feed)
Likelihood: High – if your property is on three phase power. Low if you are only on single phase power.
Fixable? Just wait for the electrical feed to come back online. Contact your power lines company for more information.
If your property is on three phase power then it is possible that one phase is out.
This offline phase would normally be powering your gate unit. In this case it is a matter of waiting for this phase to come back online for it to resume functioning.
Contact your local lines company website for more information.
Surge Protection
Surge protectors are a great way to protect your appliances from the effects of damaging power surges.
As mentioned earlier, electronics are very susceptible to damage from high voltages.
In the modern home almost every electrical device contains some degree of electronics including fridges, air conditioning, microwaves, ovens, pumps and starlink.
Surge protectors work by diverting harmful voltages away from these appliances and diverting them safely to your earthing system.
Surge protectors are small devices located in your switchboard.
These ones will protect your entire home. Other devices such as multiboards can contain surge protectors but these will only protect the appliances plugged into it.
Electricians Perspective
Temporary high voltages resulting in damage to the internal electronics, motor or 24 volt wiring of the electric gate unit is the main reason why it isn’t working in my experience. If your home is on three phase power check that a phase isn’t out by checking that other wall sockets are working on the property.
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