GFCI outlet keeps tripping why and how to fix

1) GFCI Uses

Ground Fault Circuit Interrupters are primarily used as an electric shock prevention device. They are designed to trip when tiny levels of electrical current go astray from an electrical circuit. They are far more sensitive than a circuit breaker as they are set to a very low trip level or around 6mA, that 6 milli amps or 6 thousandths of an amp (Unit of electrical current). Whilst this is extremely low, higher levels of electrical current can begin to cause harm to the human body. 

At levels of around 10 mA the human body can appear to freeze as muscles spasm and it can be difficult to let go of live electrical parts. At around 30 - 70mA the heart can fibrillate, disrupting the rhythm and causing electrocution.

A Ground Fault Circuit Interrupter is typically installed into socket outlets around the home to monitor current flow and trip the flow of electricity when current leaks to ground away from the electrical circuit. They use a very sensitive internal mechanism to monitor magnetic field strength disparities. When current flow is equal between hot and neutral wires there are two magnetic fields present which are oppositely polarised to each other cancelling each other out. The net magnetic field strength is zero. Where there are different levels of current flow between hot and neutral, there is an imbalance and a magnetic field exists. A coil detects this magnetic field and produces an electrical current 'telling' the device to turn off the power.

A GFCI should be tested monthly using the TEST button and RESET button to ensure that the device is working as the manufacturer intended. If the outlet fails to trip then you should contact an electrician to check and possibly replace the device for you. Whilst there are GFCI testers available on the market, an electrician will have more sophisticated test equipment and be able to check this more thoroughly for you.

2) Why a GFCI keeps tripping?

If you have a GFCI OUTLET TRIPPING then there are numerous common reasons why GFCI breakers or a GFCI receptacle will trip and whilst they are incredibly effective at preventing electric shocks, they cannot distinguish between an electrical shock occurring and a faulty appliance being used. 

The typical reasons a GFCI will trip are: 

• Excessive electrical equipment connected that is 'leaky'. Certain electronic equipment is known to leak a couple of mA here and there in normal operation and too much of this type of equipment connected will cause nuisance tripping of the GFCI
• Faulty electrical appliances that are potentially dangerous. Internal wiring issues with appliances can cause GFCI protection devices to trip.
• Water penetration into electrical wiring and equipment. When water enters electrical equipment and wiring it can allow cable insulation to fail and ground leakage of electrical current to occur
• Damage to cabling or equipment
• Loose wires or loose connections can sometimes cause a GFCI to trip.

There are a variety of other electrical faults and electrical issues that may cause a GFCI to trip and often an electrician will be required in order to identify the electrical hazards causing the issue.

3) How to Diagnose Tripping Issues with GFCI

Due to the variety of potential causes for GFCI outlet trips there is a good chance that damage will occur if a GFCI outlet keeps tripping and the cause is not identified. Frequent GFCI trips when there is rain may indicate that there is an issue outdoors that is causing the nuisance trips. 

It’s important not to continually reset the breaker when there is a gfci problem as doing so could cause permanent damage to parts of the home's electrical system. Whilst the amount of current needed to trip a gfci is fairly low, current leakage can cause electric shock if the device fails and if the amount of current is large enough then there could be wiring damage to the electrics when the devices trip constantly or fail.

Circuits can be tested for current leakage by using a current leakage clamp meter around the HOT and NEUTRAL wires. The current leakage clamp meter will measure the strength of the electromagnetic field difference and translate that into mA on the screen of the meter. Do not clamp the ground wire in the same test measurement as this may result in no leakage showing up.

Unplug everything from the GFCI outlet that is tripping and see if the outlet resets. If this resets with everything unplugged then it is likely that there is faulty equipment that is causing the problem. Try the equipment in another GFCI unit and see if the fault can be replicated. If the new outlet does not trip then it is possible that the tripping GFCI may be faulty.

4) GFCI breaker trips at the electrical panel

The installation of a GFCI breaker at the electrical panel is somewhat beneficial as protection for the whole electrical circuit can be achieved without the need for separate GFCI outlets. This has the benefit of protecting the wiring inside the walls against accidental damage from a power drill or other mechanical damage. 

The disadvantage is that, there may be more frequent trips due to excessive ground leakage and less available leakage across the whole circuit when compared with using separate GFCI electrical outlets.

Where a GFCI is installed at the panel, the device will trip if there is a fault anywhere on the electrical circuit that it protects. This can make fault finding electrical problems slightly trickier. The first step to troubleshooting would be to unplug everything from the circuit and attempt to reset the breaker. If this works then there is likely:

• Faulty equipment connected that needs testing to identify which appliance is at fault
• Excessive earth leakage across the whole circuit

A professional electrician is often the best solution when electrical work is required. Electrical devices can be dangerous and without the correct equipment, qualifications, and knowledge it is possible to cause electrical fires, burns, shock, and injury.

5) Summary

Identifying the possible reasons why GFCI's trip can be easier for individual outlets and more involved where a GFCI breaker protects a whole circuit. Whilst these devices are an important safety feature, they are not perfect at detecting electric shock situations. A GFCI circuit may need to be installed with consideration for how many outlets are to be protected to avoid excessive ground leakage. 

GFCI protection for outdoor areas is absolutely vital due to the additional risk of outdoor conditions and electric shock. The best person to advise on fault finding, troubleshooting and installation would be a qualified electrician. Electricians will be familiar with common GFCI issues and will have the specialist test equipment and knowledge to carry out troubleshooting steps on GFCI OUTLET TRIPPING faults.