RCD tripping: Tripped Circuit Breaker and What to do?

1) Let's start at the beginning: How do Electrical Circuits Work?

Before jumping into the reasons behind tripped circuit breakers, let's briefly understand how modern electric circuits function. An electrical circuit typically involves a Line or Hot wire, which carries the electrical current around the circuit originating from one of the home's circuit breakers located in the fuse box or electrical panel. 

There is also the neutral wire that completes the circuit by carrying the electric current back to the panel again. The flow of electricity through these wires powers various electrical devices and appliances in our homes. Electrical appliances, light fittings and equipment are connected to the Line (or hot) wire and to the Neutral so that electrical current can flow THROUGH the appliance making it operate. 

The Earth Wire, also known as the Ground Wire or Circuit Protective Conductor is a safety earth electrical connection that connects all exposed conductive parts of the electrical system to EARTH. These exposed parts are things like METAL case work on appliances, pipework and CLASS 1 or METAL light fittings. 

The electrical panel, often located in the utility room, hallway, or basement, contains the circuit breakers that act as safety measures. These breakers can trip or switch to the "off" position in case of electrical issues to prevent overloads, short circuits, and potential hazards such as electrical fires.

2) Common Causes of Tripped Circuit Breakers or RCDs

Overloaded Circuit: One of the most common reasons for a tripped breaker is an overloaded circuit. This occurs when the circuit is trying to carry more electrical current load than it can handle and reaches a dangerous level. Large appliances, power-hungry devices, or too many devices plugged into the same circuit can lead to an overload. Typical devices that overload circuits are things like a clothes dryer, washer / washing machine, heating appliances and other high powered kitchen appliances. 

Short Circuit: A short circuit happens when the Line or Hot wire comes into direct contact with the Neutral wire or another Line wire. This results in a large and sudden surge of current, exceeding the circuits capacity and prompting the circuit breaker to trip to prevent potential fire hazards. When the circuit breaker trips it will usually do so with a loud BANG! 

RCD or GFCI: GFCIs are designed to protect against electrical shock. If there is a ground or earth fault, where the live wire comes into contact with a conductive surface, the RCD or GFCI will trip to cut off the electrical supply instantly (within fractions of a second). 

The most common reason for an RCD or GFCI tripping is moisture entering the circuit wires, a light fixture outside or somewhere else like the main fuse box. The best way to establish the cause of a tripped RCD is to ask a professional electrician to come and test the system. If everything is unplugged and the device is still tripping then there is an issue on the wiring. 

Arc Faults: Arc faults occur when there is an unintended electrical discharge or sparks in the wiring. Modern electrical codes often require the installation of Arc-Fault Circuit Interrupters (AFCIs) to mitigate the risk of electrical fires caused by arcing.

Loose Connections: A loose wire in the electrical circuit can create resistance and generate heat. This can lead to a tripped breaker, damaged cables, melted electrical accessories and potential electrical fires. Regular maintenance and inspection by a qualified electrician can help identify and rectify loose connections.

Faulty Appliances or Wiring: Appliances with faulty components or damaged wiring can introduce issues into the electrical circuit. Signs of damage, burning smells, or black discoloration around outlets or switches should be addressed promptly to prevent further problems.

3) What to Do When a Circuit Breaker (MCB) Trips:

Identify the Source of the Problem: The first thing to do when a circuit breaker trips is to identify the source of the problem. Determine if the tripped breaker is associated with a particular circuit, room, or appliance. This initial assessment will guide you in troubleshooting.

Turn Off Appliances: If the breaker tripped due to an overloaded circuit, turn off some appliances to reduce the electrical load. Unplug devices from outlets and redistribute the load across different circuits if possible.

Inspect for Signs of Damage: Examine electrical outlets, switches, and devices for signs of damage, burning smells, or black discoloration. If you notice any issues, refrain from using the affected outlet or device until it's inspected and repaired by a professional electrician. We can see the plug socket here has signs of blackening and melting on one of the pins. It is also barely held in to the wall with just one screw.

Reset the Breaker: Once you've identified and addressed the issue, you can reset the tripped breaker. Move it to the "off" position and then back to the "on" position. If the breaker trips again immediately, there may be an underlying problem that requires professional attention.

Consult a Licensed Electrician: If you experience frequent trips or are unable to identify the source of the problem, it's crucial to consult a licensed electrician. Attempting to troubleshoot complex electrical issues without the necessary expertise can be dangerous and may lead to further complications.

4) Why immediate action is best:

Fire Hazard Prevention: Tripped circuit breakers are often a result of conditions that could lead to electrical fires. Addressing the issue promptly reduces the risk of fire hazards, ensuring the safety of your home and occupants. Aside from fire hazards, permanent and serious cable and electrical system damage can occur when electrical faults are left without investigation.

Protection Against Electrical Shock: Electrical faults to earth and faulty wiring can pose a significant risk of electrical shock. Timely intervention, especially in the case of GFCI or RCD tripping, safeguards against potential electrocution. These devices are designed to save lives but repeated tripping without electrical repairs will lead to their demise and will mean that the electrical system no longer has electric shock protection. A common mistake made by customers is the assumption that the GFCI or RCD is faulty where the likelihood is that there is actually a fault within the electrical system. 

Preventing Electrical Equipment Damage: Sorting out those electrical issues quickly protects your appliances and devices from damage. Repeated fault currents and power disconnection is likely to damage sensitive electronic equipment. Computers, for example, are not fond of being repeatedly disconnected from the electrical supply and are not particularly cheap to repair or replace!

Compliance with Safety Standards: Adhering to safety standards, such as the National Electrical Code, BS7671 Wiring Regulations or local wiring regulations in your territory is vital for the overall safety of your home. Regular inspections and maintenance by a qualified electrician ensure that your electrical system complies with these standards. If your home has not been inspected by an electrician in the last 10 years then IT'S TIME FOR ONE NOW!

Peace of Mind: Knowing that your home's electrical system is in good condition provides peace of mind. Regular checks, prompt action, and professional maintenance contribute to the smooth operation of your electrical circuits. REMEMBER, just because everything appears to be working or “we have never had a problem before” does not mean that everything is FINE. A system can have serious electrical defects and continue to function with a great degree of normality to the untrained eye. When a secondary fault develops, this can have devastating consequences! 

5) When to Call a Professional Electrician:

While some minor issues can be addressed by homeowners, certain situations warrant the expertise of a licensed professional electrician:

Frequent Trips: If your circuit breaker or your RCD keeps tripping frequently, it indicates a problem that requires professional attention. An electrician can conduct a thorough inspection to identify and rectify the issue. Many RCD tripping problems are not mega expensive to have rectified but the costs can mount up if these issues are left without repair. Cable damage and other problems can grow into more expensive issues.

Arc Flash or Sparks: If you notice sparks, an arc flash, or any unusual visual signs when resetting a breaker, do not attempt to handle it yourself. This is a serious issue that requires immediate professional intervention. Flashes and bangs from electrical equipment are NOT GOOD and an electrician should be called to check on things. 

Certain flashes MAY be ok, for more information check our other article 

Burning Smell: A persistent burning smell around outlets, switches, or the electrical panel is a clear indication of a problem. Cease using the affected equipment or circuit and consult a professional electrician promptly. The smell is normally a fishy smell from electrics and indicates that there has been severe and prolonged overheating or even fire.

Power Loss in One Area: If a specific area of your home experiences a persistent power outage, it could be indicative of a localised wiring issue. Don’t assume that if everything comes back on then it’s all fine, intermittent power loss to lights, sockets or other electrical circuits is normally indicative of a serious electrical defect that requires immediate attention. 

DIY Attempts Fail: If your attempts to troubleshoot and resolve the issue on your own are unsuccessful or if you are unsure about the root cause, it's best to call a professional electrician. DIY electrical work can be very dangerous and beyond the obvious checks, interfering with electrical wiring or panels carries great risk for the untrained and inexperienced.

Safety should always be the top priority for all electricians and homeowners. A well-maintained electrical system is one that presents minimal risk of electric shock, fire and other dangers to the homeowners and users of the system. 

If you find that you are having issues with your electrical system or just want to know that you have done everything you can to make sure it's safe, check out our electrical safety check list for things that you may not have thought of.