A Guide to Residual Current Devices (RCDs): Their Types and Functions

Today, electrical safety in any system is very important, and one of the best ways to protect from electrical faults is through Residual Current Devices (RCDs). In homes and industries, RCDs offer essential protection in cases of electric shock, limiting the occurrence of electrical fires. But what are the RCDs, and how do they work? In this guide, you will learn what an RCD is, the types of RCDs, their uses at different locations, function of residual current device, and its price range. 

What is an RCD?

An RCD (Residual Current Device) is a fast-acting protective device that interrupts the circuit to avoid lethal electric shock. It measures the variation in current which enters a circuit from that which flows out of the circuit. If there is any imbalance, it shows a leakage current, which may be caused by contact with live wires by other naked-wire sources. This is where the RCD identifies and breaks the circuit before anything unfortunate happens.

Unlike fuses or circuit breakers, which primarily protect appliances from overloading and short circuits, RCDs are designed to safeguard human life. It responds within milliseconds to even small current leaks, typically no more than 30 milliamps.

How do RCDs work?

RCDs measure the amount of current that is passing through a particular circuit. In an ideal circuit, the current entering an appliance and the current to be returned should be the same. If a fault occurs, this causes imbalance; it will happen, for instance, when a person touches a live wire. The RCD senses this disparity, and if the difference is improved beyond the limit (typically 30 milliamps), then the power is disconnected nearly immediately, taking approximately 25-40 milliseconds, hence minimising the possibility of getting an electric shock.

In other words, RCDs could be regarded as saving devices. They are important in sections of the building that are likely to come into contact with moisture, such as the kitchen and the bathroom or any place that exposes people to live parts of the equipment.

No, what is an RCD fuse box? The term RCD fuse box is a combination of RCD within the main electrical fuse box of a building. This ensures that the entire electrical system is protected with the protective functions of an RCD.

Types of Residual Current Device

RCDs can be of several types and are developed for specific purposes, as described below. 

Fixed RCDs

These are wired into the main distribution board, protecting one or several circuits. These provide premium safety throughout an electrical system and are appropriate when securing several devices and sockets in households and commercial spaces. A fixed RCD is sized for a large area and may be installed where there are several items or circuits to protect.

Socket-outlet RCDs

These are fitted directly into sockets and offer extra protection on the devices plugged into that socket. Socket-outlet RCDs are recommended for installation where you want to protect certain appliances or in any area where water splashing is dangerous, like in the bathroom or kitchen. Fixed forms of RCD are more generalised than the other types of RCDs that we are discussing.

Portable RCDs

A portable RCD is a temporary protective device easily movable and fitted into any standard socket. These are helpful, especially when using power tools and electrical devices at dangerous places such as construction sites or surroundings. If you are using an extension lead or an outdoor electrical appliance, a portable RCD is a good means of increasing safety.

Application of Residual Current Device

The application of residual current devices spans both residential and commercial settings. Here are some key points to understand what RCDs are used for. 

Residential Homes

In homes, RCDs are typically installed in fuse boxes to protect against electrical appliances, circuits, and wiring faults. They are particularly important in kitchens, bathrooms, and outdoor areas where water and electricity might come into contact.

Commercial and Industrial Buildings

In industrial settings, RCDs are critical in protecting workers who use heavy-duty electrical equipment. They are frequently used on construction sites and in workshops where the risk of electric shock is heightened due to the nature of the work.

Outdoor Environments

RCDs are essential in environments where electrical equipment is exposed to moisture, such as gardens or outdoor events. Using electrical appliances outdoors increases the risk of electric shocks, making the application of residual current devices indispensable.

Hospitals and Care Homes

In healthcare environments, protecting patients and staff from electrical hazards is paramount. RCDs ensure that medical equipment operates safely and prevent potentially life-threatening electrical faults.

Residual Current Device Price

When considering the residual current device price, various factors include the type of RCD, its rating, and the brand. Typically, prices range from INR 500 to INR 5000, depending on the device's features and specifications. For instance, a fixed RCD installed in a fuse box will usually cost more than a portable or socket-outlet RCD due to its complexity and broader protection coverage.

For high-quality RCDs, look for reputable brands like Schneider Electric eShop, which offers durable and reliable devices, is advisable. Investing in a good-quality RCD may initially cost more, but it provides long-term safety and peace of mind.

Read Also - Difference between MCB, MCCB, RCB, RCD, RCCB, and RCBO

Conclusion

RCDs are a crucial component of modern electrical systems, safeguarding people and property from electric shock and fire dangers. You can make informed decisions about your electrical safety needs by understanding what RCD is, the types of residual current device, and their functions.

Whether you're looking for a fixed RCD for your home's fuse box, a portable one for outdoor use, or simply want to know more about how these devices work, RCDs are invaluable in ensuring electrical safety. Brands like Schneider Electric eShop provide a wide range of reliable and efficient RCDs, ensuring that your electrical systems are as safe as possible. So, if you're considering enhancing the safety of your home or workplace, investing in a quality RCD is a smart and lifesaving decision.

Frequently Asked Questions

Q1. What is RCD, and how does it work?

Ans: An RCD (Residual Current Device) is a safety device that prevents electric shocks by detecting leakage currents and cutting off power. It works by measuring the current flowing in and out of a circuit and cutting off electricity if it detects an imbalance.

Q2. What are the different types of Residual Current Devices?

Ans: There are three main RCDs: Fixed RCDs, which are installed in fuse boxes; Socket-outlet RCDs, integrated into specific outlets; and Portable RCDs, which can be plugged into any standard socket for temporary use.

Q3. What factors affect the price of an RCD?

Ans: The residual current device price depends on the type of RCD, its features, and the brand. For reliable and durable RCDs, Schneider Electric eShop is a trusted source, offering a variety of RCDs suitable for different applications.