Learn what switchgear is, how it protects your EV charger’s electrical circuit and how to identify the RCD, MCB or RCBO connected to your charger.
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What is switchgear?⚡
Every electrical circuit in your home needs protection against electrical faults. The protective devices used to control and protect these circuits are collectively referred to as switchgear.
The switchgear for your EV charger helps protect the circuit against excessive current, overheating and electric shock.
Switchgear is normally located inside a consumer unit. A consumer unit may also be described as a fuse box, distribution board or switchboard—these terms generally refer to the enclosure containing the switches and protective devices for your property’s electrical circuits.
Your EV charger will normally be protected by either:
- An RCD and a separate MCB; or
- A combined device called an RCBO.
What is an Residual Current Device (RCD)?
RCD stands for residual current device. It is designed to disconnect the electricity supply quickly if it detects current flowing along an unintended path, helping to protect people from electric shock.
An RCD:
- Has a test button, which may be marked “T” or “Test”
- Is commonly wider than a standard MCB
- Works alongside a separate MCB that provides protection against excessive current and short circuits
The appearance and labelling of an RCD can vary between manufacturers.
What is an MCB?
An MCB protects an electrical circuit against excessive current caused by an overload or short circuit.
An MCB:
- Does not normally have a test button
- Is commonly a single-width device
- Usually has a letter, such as B or C, before its current rating—for example, B40 or C40
The letter indicates the device’s tripping characteristics, while the number indicates its current rating.
Sample MCBs
What is an RCBO?
RCBO stands for residual current circuit breaker with overcurrent protection.
An RCBO combines the functions of an RCD and an MCB in a single device. It provides protection against electric shock, excessive current and short circuits.
An RCBO:
- Has a test button, like an RCD
- Usually has a letter, such as B or C, before its current rating
- May be a single-width or double-width device
The appearance and labelling of an RCBO can vary between manufacturers.
Sample RCBO's
Indra switchgear recommendations
Indra recommends the use of a C40 overcurrent protection device to reduce the likelihood of unwanted tripping.
A 32A device may be suitable in some circumstances, but because a 7.4kW charger can draw close to 32A for extended periods, it may be more likely to trip.
The type and rating of the protective device must be determined by a qualified electrician. They will assess the electrical installation and ensure that the equipment selected is suitable and complies with the applicable wiring regulations and manufacturer’s instructions.
How to identify your charger’s switchgear
Your installer should show you which consumer unit and protective device control your EV charger.
If you need to identify them later:
- Look for a label such as “EV”, “EV charger” or “car charger”, or for a car symbol
- Check whether your charger is supplied from a separate consumer unit, which may be located near your electricity meter or main fuse
- If it is safe and easy to do so, visually follow the charger’s supply cable towards the consumer unit
Do not remove the cover of a consumer unit or touch any internal wiring. If you cannot identify the correct protective device, contact a qualified electrician.
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EV Consumer Unit Example
Testing your RCD or RCBO
Find out how to test the RCD or RCBO connected to your Indra charger