Different Types Of RCD Switches

The main reason why RCD switches are installed in properties is to protect circuits and equipment from short circuits. Also, the safety switch protects people as it will reduce the risk of electric shock if a short circuit occurs. The switch constantly inspects circuits to potentially find an earth leakage and immediately stop the flow of electricity in the circuit. 

If wanting to know the differences between circuit breakers and RCD switches as they both are installed for electrical safety our blog provides more detailed information.

There are five main types of RCD switches that are installed around properties. These safety devices work in different areas and have different strengths depending on the situation. There are also different variations of RCDs that allow them to be installed in different locations and suit various needs. The five main types of RCDs are:

Type S

Type S RCDs have an in-built feature to delay the time of shutting off electrical power to a circuit. This is because in places where there are a number of appliances and equipment that use a large amount of power the chance of nuisance tripping is higher. Type S RCDs are mainly used to protect against electrical fires over protecting people from electrical shock. 

Type AC

This type of RCD switch is used in most buildings as a protection against short circuits. They do not have a time delay and will immediately cut off the electrical power when there is a spike in the circuit. The main types of circuits these RCDs protect are those that have no other electrical components. This means that Type AC RCDs protect appliances and systems such as ovens, ceiling fans, heaters and lighting circuits. 

Type A

Type A RCDs are installed for appliances and devices that have additional electrical components. They can work alongside Type AC RCDs and ensure circuits are protected from unwanted rises in electrical power. Some systems Type A RCDs protect are dimmers on lights, electric vehicle charging equipment, inverters and induction hobs. 

Type F

To protect devices, equipment and appliances that are frequency controlled will be protected by Type F RCDs. These RCD switches will be able to work alongside Type A and AC RCDs to protect appliances from electrical surges. The main systems that Type F RCDs look over can include dishwashers, clothes dryers, power tools and washing machines. 

Type B

Type B RCDs are mainly used to protect devices and appliances that are single or three-phase. This can include lifts, escalators, inverters, uninterrupted power supplies and other larger or industrial devices. These types of RCD switches are able to work with Type AC, A and F RCDs to help protect circuits. 

The four main types of RCD variations that are how the different RCDs are installed are:

Meter Box

These RCDs are installed within the main electrical switchboard and at least two are installed. The RCD switches are mounted within the meter box and are required to be installed in the property. 

RCDs and Circuit Breakers

Utilising both circuit breakers and RCDs are common to add further protection from electrical faults and problems. Both the circuit breaker and RCD switches will be installed in the switchboard to protect devices and people. Often during a switchboard upgrade adding the combination of safety devices will occur. 

Portable

When appliances are not able to run on a circuit protected by an RCD then a portable one can be used. This can be for power tools and other appliances where an extension lead will connect the device to the portable RCD.

Power Point

For places in properties that might not be directly connected to the RCD switches or where appliances are used frequently, an outlet can have an in-built RCD switch to protect the appliance. 

For more information about RCD switches and how they operate we highly recommend reading our blog for more details. We also encourage reading our blog ‘how to test and replace an RCD switch’ to know the best methods for testing your RCD correctly.