What Is An RCD?

Residual current device (RCD) is a safety device designed to switch off the power if there is a fault, acting as a trip switch. RCDs go beyond the safety levels offered by regular fuses and circuit breakers. An RCD is usually located in the fuse box (consumer unit). It might also be located between the circuit breaker and power sockets.

An RCD usually goes on the supply side of the equipment it protects, often inside a fuse box or on a distribution board. Some equipment may also have an RCD built into the plug. There are different types of RCD's that can serve various requirements.

RCDs generally work by monitoring the current flow in a lower voltage circuit. If they detect an issue with the current flow they shut off the power to the entire system, which prevents electrocution or severe injuries.

It makes sure that electricity will not flow to your home or business in the event of a fault, such as a short circuit. In simple terms, the RCD acts as a failsafe device and can be a lifesaver.

Why Does The RCD Keep Tripping?

There are many reasons why your RCD can keep tripping, and in this section, we will explore some of the more common causes for it. It is important that you pay close attention to this section especially prior to electrical rewiring as this will help address most of the issues at the forefront.

Faulty Appliance

A faulty appliance is one of the main causes why RCD keeps tripping. Technically, RCDs are designed to protect against electrical circuit faults from faulty appliances. If an RCD trips, it has done its job and removed the faulty electrical circuit from the power network which could potentially cause a fire. In most cases, this will be caused by appliances that have been poorly installed or maintained.

Incorrect RCD Current Rating Used

Each Residual Current Device is designed to trip when the current flowing through it exceeds a certain value. If the RCD’s rated value is too low, it will trip unnecessarily. You may find that your RCD is tripping repeatedly. This could indicate that it has the wrong rated current and should be replaced with one of the correct rating.

All RCDs should trip when the current exceeds its rating. A sign of an under-rated RCD is one that trips repeatedly, particularly on small overloads.

Low-Quality RCD

A low-quality RCD is a common cause of premature tripping. A true RCD will reset itself within a few minutes. It should never trip while it is resetting. Good quality RCDs should be able to withstand the current that passes through them during a reset continuously for at least an hour without overheating.

Accurate tripping is a great feature of RCD’s. It means that they are working correctly and if anything gets in the way such as a fault or a blockage it can trip quickly and easily. A low quality RCD will not be able to detect correctly and trips over time.

Fridge/Freezers Cooling Down

When your fridge or freezer begins to cool down, the motor inside it increases its work rate. This can cause power spikes, even when plugged into an RCD protected power point.

An RCD can react if there is a sudden rise in electrical current use or leakage current, due to the contents of your refrigerator or freezer thawing out.

Occasionally, a poorly connected appliance can cause a spike in electricity supply. If this happens, the RCD will trip and reset as it is designed to do. Electricity supply should return to normal shortly afterwards.

Moisture In Electrical Sockets

Moisture in outside electrical boxes and sockets can cause a trip by the RCD. It is vital that you detect moisture in your socket box early on. Exterior electrical terminal boxes and outlets should be periodically checked for moisture; signs of moisture may include weather-sealed cases that have deteriorated and/or reset switches that trip randomly.

Use Of Older Washing Machines/Dryers Or Motors/Pumps

Spikes can also be the result of poorly maintained or incorrectly connected equipment such as older electrical appliances, such as washing machines and dryers, which can cause the power to surge. With motors and pumps, if there is a correlation between the frequency/time of surges and use of an appliance, then it is most likely that that appliance was causing the RCD trip.

This trips when there is a sudden spike of electricity that can cause injury or damage. These spikes can be caused by lightning strikes, electrical faults, power tools, appliances with motors or pumps, old washing machines and dryers and so on.

Issues With Central Heating Systems

A faulty component in your central heating could cause RCD trips. An RCD trip is often triggered when the faulty part turns on and off repeatedly, which may lead to false alarms. Permanent damage could be caused to electrical equipment if your home suffers frequent or prolonged RCD trips due to a faulty component.

Water In Wiring

Maintaining a high standard of electrical safety is crucial. When the resistance of a piece of wiring exceeds a certain level electricity will travel via a shortcut. If this path happens to include water or dampness, your RCD will trip to protect you from the risk of electrocution, which is probably why the RCD keeps tripping.

In many cases, residents and vacationers alike fail to properly care for their recreational vehicles and water intrusion can occur. Due to this, there is a possibility of RCD trips.

Fixing A Tripping RCD

Having looked at the various causes on why RCD keeps tripping, let’s expand further on each of them to understand how we could fix a RCD that keeps tripping.

How To Fix Faulty Appliance From Tripping

If you suspect that a faulty appliance may be causing your RCD to trip, try unplugging every electrical appliance in your home and checking whether your RCD resets correctly. If it does, plug in each appliance one by one and reset your RCD as you plug in each item.

If suddenly the RCD starts tripping again shortly after plugging in one item in particular, then you’ve likely identified the specific cause.

How To Fix Incorrect RCD Rating Used

If your circuit breaker is rated beyond the requirements of the home’s electrical system, it may need to be replaced. Professional electricians can visit homes for visual inspection to determine whether or not the RCD needs to be replaced.

How To Fix Low-Quality RCD

It is best for a trained electrician to replace low quality RCD. In most cases, this kind of professional installation is necessary. It can even be dangerous to replace the RCD yourself – this is why you should hire a reputable contractor to replace it.

How To Fix Fridge/Freezers From Tripping

It might be possible that the motor cooling the fridge or freezer is broken. A professional may recommend having it replaced or rerouting the wires connected to the appliance to prevent tripping. If the motor is tripping, it would be best to call a professional. You can get it replaced or reroute the wiring to prevent RCD trips.

Fixing The RCD Trips Caused By Moisture In Electrical Sockets

The moisture present outside electrical boxes or sockets can be risky when it comes to the safety of the property.  When you encounter an electrical problem due to moisture present in outside electrical boxes or sockets, it is important to first turn off the power supply completely before drying the electrical boxes or sockets. If the weather seals have been destroyed beyond repair, it is recommended that you have them replaced.

Fixing Trips From Older Washers And Motors

A licensed electrician  can take a look at your washer or dryer if you believe that one of these devices is the cause. If you are right, they may suggest having a particular part repaired or replaced, depending on the severity of the issue.

Fixing RCD Trips Caused By Central Heating Issues

If you have a RCD tripping due to central heating problems, call an electrician to assess your home’s wiring. The RCD will trip if the correct electrical current cannot be delivered to the part being used. Depending on the scale of the problem, you might need to replace old wiring or have an electrician do it for you.

Alternatively, you can get in touch with a professional electrician who will be able to give suggestions as to how you can avoid similar issues in the future, such as repairing now and replacing in the future.

How To Fix RCD Trips Caused By Water In Wiring

The right heating and ventilating systems are vital to ensuring that moisture is not present in your home’s wiring. In other words, improperly ventilated or heated homes can cause water to damage electrical wiring. Heating and ventilation systems can be combined with humidity control devices, such as a hygrostat (humidistat) or a hygrotherm, to regulate the moisture levels in a home.

How To Remove An RCD From Your Fusebox

In order to remove the RCD from the fuse box, you must first ensure that all electrical load has been disconnected from the RCD. Once all loads have been disconnected, you will notice a small tab on the front of the RCD. Take a flat bladed screwdriver and insert it into the slot on the back of the RCD. Next, firmly pull down on the slot as you pull the RCD away from the fuse box.

In most cases, the RCD is located in the fuse box. The RCD switch may be labelled “RCD.” Alternatively, you may locate a “T” or “Test” above it. Make sure the power to the circuit is switched off before taking out the screws that attach the RCD to the fuse box.

Replacing An RCD In A Fusebox

To replace an RCD, you will first need to remove it using the steps described above. Once the RCD is removed, another can be put in place by completing the removal steps in reverse. However, a new RCD will also need to undergo various tests. While replacing an RCD can be done DIY, unless you are well-studied and highly competent in the area, you should hire an electrician. This is because there are multiple aspects to correctly replacing an RCD.

The cost of replacing an RCD can range between between £30 and £70 including both installation and supply costs. An RCD itself will likely cost between £10 and £40.

How To Prevent An RCD From Tripping?

To prevent RCD trips, you should conduct regular appliance maintenance on your RCD, keeping it free from dust and damage. Checking that appliances are rated for the correct mains voltage can help determine if the appliance is faulty.

It’s also worth checking that your equipment has a current rating that is appropriate for the amount of power being drawn from it.

To reduce the risk of an RCD tripping due to electric moisture, ensure that electrical wiring is adequately ventilated, ensuring that there is no moisture present in sockets or electrical boxes. The power must be turned off before inspecting sockets/boxes. Installing a device to control humidity levels, ventilation fans and good sockets will keep you safe at home.

Consequences Of Not Fixing An RCD

If your RCD keeps tripping, it’s important that you pay close attention to it as it can otherwise lead to many hazards such as the risk of fire and electrocution. An RCD which is continually tripping may already be faulty or low-quality to begin with but either way repeated tripping can cause the RCD to deteriorate over time.

Fire

Depending on the model, RCDs may be used to protect against electrical fires. A faulty or broken RCD can make a home more vulnerable to fire and lead to unnecessary and dangerous conditions.

Electrical Malfunctions

If an RCD is unable to trip, it may become damaged over time, leading to electrical issues. Damaged circuits can be a fire hazard, increasing the risk of electrocution, damage to the appliances and wear and tear on the wiring.

You could be putting yourself and your family at risk if you have an electric issue, but don’t realise. A non-functioning or faulty appliance is not always obvious, which means you could become accident-prone with no RCD protection in place.

Final Thoughts

From the above discussion, it can be understood that it’s important that you continuously watch if the RCD is in a good condition. Additionally, you would need to ensure that they are well maintained so you can prevent any hazardous and harmful risks such as fire and electrocution. You would also need to ensure that your property follows the local regulations.

If all of this seems overwhelming to you, you can always contact your local electrician to help fix any issues with an RCD that keeps tripping.