A power surge, lost electrical feed, faulty dimmer, faulty switch or a faulty LED driver are all reasons why LED lights won’t work after a power outage.
Unusually high voltages can often be generated before a power outage occurs.
This can occur due to a fault with a nearby supply transformer or something interfering with the power lines such as trees touching the lines or a car crashing into a pole.
These temporary high voltages can wreak havoc on electrical components in your home such as LED lights.
For more information on what has caused the fault get in contact with the company that manages the power lines.
This post will explain five different reasons why the LED lights aren’t working and what can be done about it. This is taken from years of experience working as an electrician.
LED Wiring & Fault Finding
LED lights are an energy efficient and versatile style of lighting.
LED stands for ‘light emitting diode’.
LEDs contain electronic components which are designed to operate at a specific voltage and current set by the LED driver.
The LED driver converts the incoming voltage which should either be 120 volts (USA) or 230 volts (UK/NZ/AUS) AC into a suitable voltage and current for the LED light to operate.
These components of the LED light are designed to work with a steady and stable incoming voltage which it receives 99% of the time.
A power surge can sometimes double that voltage or even worse.
Dimmers on the circuit are often affected as well. Dimmers for LEDs contain electronic components which are susceptible to high voltages.
The switch itself may have burnt out due to the high voltage arcing across loose wires or anything behind the switch.
If this has happened check your switchboard containing circuit breakers.
For LED lighting there should be two circuit breakers, an MCB and an RCD.
MCB’s are skinny breakers that will trip when a short circuit or overload occurs. For the average person, an RCD can be identified from other breakers by a small ‘test’ button on the face.
Short circuits at any point in the circuit. This can include:
- the LED light
- the LED driver
- light switch
- dimmer (if present).
A tripped breaker is the first clue.
Next there should be an RCD present. An RCD will trip when a ground fault occurs. Ground faults are responsible for electric shocks. This is why RCD’s need to be on lighting circuits.
Again, a ground fault could occur with the LED light, LED driver, switch or dimmer.
Neither of these protective breakers (MCB or RCD) will protect your appliances from a power surge. A surge protector will protect your home from high voltages such as those generated from the power supply network or lightning by diverting the electricity safely to earth. This thereby protects your appliances.
Let’s look at five reasons why the LED lights aren’t working.
LED Lights Not Working After A Power Outage? – Reason #1
Power Surge
Likelihood: High – contact your local lines company for more information on the electrical fault.
Fixable? If high voltage has gone through appliances it is unlikely that they can be fixed economically and should be replaced.
A power surge is a common occurrence alongside an outage. These surges can be due to issues with a nearby supply transformer, tree branches touching power lines, accidents with the power lines and many other reasons.
The result is that appliances designed to handle either 120 or 230 volts receive much higher voltage. This causes them to burn or short out. This can damage the following components associated with LED lights – the driver, the switch, any dimmers, the light itself.
LED Lights Not Working After A Power Outage? – Reason #2
LED Driver Faulty
Likelihood: High because it contains electronics which are susceptible to surges.
Fixable? Replacing the driver is usually most cost effective.
An LED driver which has been damaged from a power surge will typically give clues. One clue is black carbon on the driver case. Another is signs of melting or discoloration on the driver case. Another is a weird metallic smell.
A breaker may have tripped in the switchboard.
LED Lights Not Working After A Power Outage? – Reason #3
LED Light Faulty
Likelihood: High because it contains electronics.
Fixable? Replacing the light is more cost effective.
The LED light can be damaged from a power surge as it contains electronics. It will either not turn on or start flashing. Replacing is the best option here.
LED Lights Not Working After A Power Outage? – Reason #4
Switch Faulty
Likelihood: Possible if there is debris behind the switch or anything that could cause a short with high voltage.
Fixable? Replacing the switch mechanism or entire switch (depending on damage) is the solution.
A switch can be damaged from a high voltage surge if there is debris behind the switch. This causes the circuit to arc and short out. This can leave signs such as black carbon around the outside perimeter of the switch. The switch may also have signs of melting or heat. There could also be a fishy smell (due to ammonia from burnt cables). A breaker may also have tripped in the switchboard.
LED Lights Not Working After A Power Outage? – Reason #5
Dimmer
Likelihood: High – if a dimmer is present.
Fixable? Replace the dimmer.
As a dimmer contains electronic components it is susceptible to damage from power surges. This can cause the dimmer to give off weird smells. The dimmer can have signs of black carbon or melting under the control knob. A breaker may have also tripped at the switchboard.
Electricians Perspective
A power surge alongside an outage is a common occurrence. It is likely to have damaged the LED light, LED driver, light switch, or any dimmers present. It could have damaged multiple components.
Installing a surge protector is the best way to prevent this happening again in the future. It is installed in the switchboard and will protect your entire home.
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