If you notice a problem with one outlet, and it seems to be affecting others, you might think it’s the fault of the bad outlet.
However, this is not necessarily the case. The outlet might be bad, but it could be faulty wiring or a circuit breaker.
Whether a bad outlet can affect others depends on the internal circuitry’s structure and how it is connected. A bad outlet can affect others on the same circuit detrimentally. In a worst-case scenario, it could cause an electrical fire.
You can minimize the risk using a special outlet and a good circuit breaker.
I’ve revealed what factors make an outlet go bad, the common causes behind it, and how to tell if it is bad below. I’ve also highlighted the role of GFCI and AFCI outlets.
A Bad Outlet on the Same Circuit
Ordinary outlets are usually connected in multiples on the same shared circuit.
Only a bad outlet under this arrangement could potentially affect other outlets, i.e., if it’s not on a dedicated circuit. If any outlet is faulty on that shared circuit, it could cause a chain reaction depending on the nature and severity of the fault.
Whether it affects others also depends on what protection measures you have in place.
Factors that Could Make a Bad Outlet Affect Others
A bad outlet is more likely to affect another outlet if:
- It’s an ordinary outlet rather than a GFCI/AFCI one.
- The other outlet is on the same shared circuit as the bad one.
- The fault is in the wiring.
If the fault is confined to the outlet, i.e., not in the wiring, it should not affect the other outlet(s). Furthermore, GFCI-protected outlets protect against moisture and AFCI ones against fire.
Other External Causes
Besides a fault in the wiring, other outlets can also be affected if the origin of the fault is not in the outlet itself but in the breaker or fuse box.
A tripped circuit breaker would cut off supply to all the outlets on the same circuit it controls. So, if several outlets stop working together, don’t automatically think one of the outlets is bad. You should check the circuit breaker as well.
Similarly, loose, faulty, or damaged wiring anywhere along the circuit could affect all its outlets, not just one.
Common Causes of a Bad Outlet
If the cause of an outlet being bad is within the outlet (rather than the circuit breaker), it could be due to one of the following five reasons [Dimock, 2007]:
- A loose screw
- Insulation caught under a screw
- An inadequate push-in terminal
- A slipped back-in-wire connector
- Insulation caught in a wire connector
If, for instance, you notice a loose screw, tightening it should resolve the problem.
How to Tell if an Outlet is Bad
To know whether an outlet is bad, you can look for certain signs to prevent further damage to other outlets on the same circuit.
Here are some common symptoms to look for:
- The switch fails to turn the appliance on or off.
- The plug comes loose easily and doesn’t stay in the outlet.
- A warm outlet usually happens if you plug in too many devices in the same outlet.
- Melted prong is usually due to higher wattage than the plug can handle.
- Burn marks on the outlet, which are usually dark brown or black.
An outlet should never be in a condition like the one shown below. It should be replaced immediately, but more importantly so, if it’s on a shared circuit.
In some cases, you should take action immediately because they are signs of a more serious situation:
- A visible spark in the outlet
- Smoke from the outlet
You can also look for symptoms in whatever is plugged into that outlet, such as:
- Dimming or flickering might be due to an open main wire or a bad appliance.
- A shock when touching it might be due to a ground fault or miswiring.
- Failure to turn it off might be due to miswiring or a bad appliance.
- Failure to work might be due to overload, a ground fault, an open connection, miswiring, or a bad appliance.
I also mentioned the possible causes, so you’ll know what to do or first check for before replacing the outlet. If you suspect the outlet itself is faulty, you should replace it.
GFCI and AFCI Outlets
GFCI and AFCI outlets are specially designed to offer extra protection but are not immune from going bad.
A GFCI outlet that protects against moisture can still go bad if excessive water gets inside. Likewise, an AFCI outlet, designed to protect against fire, can still go bad if it burns or is exposed to fire.
However, they are made to minimize the risk of going bad if the problem is minor and internal.
So, if water getting inside and arcing are the risks, you should replace the ordinary outlet with a GFCI or AFCI respectively.
GFCI outlets are also designed to shut off the entire circuit in case of a ground fault. Usually, this only happens if the circuit arrangement is like the top one in the illustration below and only if it’s above 4-6mA. It doesn’t mean it has harmed the other outlets; rather, it protects the others from getting affected.
Still, GFCI and AFCI outlets don’t go bad easily. If it trips, you normally only need to reset it if the hazard is no longer present.
Also, if the outlet is outside, it should additionally have a weatherproof cover, and if you have a child in the house who plays near an outlet, replace it with a tamper-resistant outlet.
References
Larry Dimock. Circuit Down. Lulu.com.2007. Retrieved from https://www.google.com.pk/books/edition/Circuit_Down/-S9jQAcrsFkC?hl=en&gbpv=0
Ray C. Mullin, Phil Simmons. Electrical Wiring Residential. Cengage Learning. 2017
Video References
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