Can a bad extension cord cause a breaker to trip?
Yes, absolutely. A bad extension cord can certainly cause a breaker to trip. In fact, a bad extension cord can cause a breaker to trip for several reasons. In this post I’m going to cover a few reasons why a bad extension cord causes a breaker to trip.
Firstly, it’s a good idea to understand why a breaker will “trip”. When a breaker trips, it is designed to rapidly and automatically cut off your power supply.
While this can be quite inconvenient, it happens for a very good reason. Mainly to stop someone from getting an electric shock, or causing a fire. A breaker (or MCB) will only trip if a certain fault threshold is met.
If we are talking about Miniature circuit breakers (MCB’s), then there are two reasons they would “trip”.
One reason these would trip is because of a circuit overload. This means you’ve got too many things which draw a lot of current plugged into the circuit (i.e – many heaters plugged in). The breaker trips to stop the wires from overheating and potentially causing a fire.
The other reason a breaker might trip is to prevent a short circuit from causing a fire or electric shock.
In my experience, a short circuit would be the most likely reason for a breaker to trip – if it was an MCB.
If we are talking about RCD (residual current device) breakers, then the reason for it to trip is current is leaking to earth. Its main purpose is to prevent people from getting electric shocks from touching anything, such as a metal table, which might be receiving this “leaked” current.
Can A Bad Extension Cord Cause A Breaker To Trip? – Safety Precautions.
If you have this extension cord currently plugged into an outlet, I’d suggest that you unplug it first before reading on.
Never inspect an extension cord which is plugged into an outlet – especially if you suspect that it is a bad extension cord.
Now that you have your unplugged extension cord, can you see any damage?
Can a bad extension cord cause a breaker to trip? – Reason #1
Damaged Insulation
I’ve seen insulation on extension cords become bad for many reasons.
Extension cords can have nicks and abrasions which expose the wires underneath.
From dogs chewing cords, rats chewing cords, vehicles driving over cords. The list goes on.
You will probably need to carefully inspect your extension cord to find evidence of damaged insulation.
Damaged insulation on your extension cord is bad because it can cause a short circuit or earth leakage like I described above. Both of these will cause a breaker to “trip”.
Can a bad extension cord cause a breaker to trip? – Reason #2
Insulation Pulled Away
The next thing you will need to check is if the insulation reaches all the way to the plug. When people yank an extension cord out of an outlet, the insulation can get pulled away from the plug exposing the cables. This tends to happen over a period of time. Exposed cables are more prone to damage. This eventually leads to the wires coming out of their terminals, or moisture, dust or dirt getting into the plug which can cause a short circuit, resulting in tripping a breaker.
Can a bad extension cord cause a breaker to trip? – Reason #3
Damaged Plugs
It is a good idea to check if the plugs have any physical damage. For example, does the plug look squashed or deformed in any way. If they do, this can cause a breaker to trip.
Can a bad extension cord cause a breaker to trip? – Reason #4
Faulty Appliance Plugged Into Good Extension Lead
If you’ve looked at your extension cord and can’t find any damage to the insulation or to the plugs, then it is possible that your extension cord isn’t bad. Instead it is the appliance plugged in to the extension cord that is bad. Obviously, I’d get a registered electrician to confirm this for you.
The simple way to check is to get another extension cord and plug the appliance into that. If the breaker trips again then it’s likely that the appliance is the real cause of the problem. Again, you should talk to a registered electrician to double check.
What You Should Do If The Extension Cord Is Bad
In conclusion – Can a bad extension cord cause a breaker to trip? Yes, absolutely.
You should either repair this extension cord or throw it away and replace it.
With an extension cord, a registered electrician is able to repair the damaged cables and insulation. They can also repair or replace broken plugs and provide a test and tag for the extension lead.
However, if you think that the extension cord is very bad then the simplest solution is to simply throw it away and replace it with a new one.
It isn’t worth having a bad extension cord lying around which could injure people, or damage property, or whatever was plugged into the end of the cord.
Having knowledge about what is happening with a bad extension cord can help you save money when it comes to dealing with electricians.
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