Home EV charger installation FAQs

Laura Kinsley | 25/05/2023

A home EV charger allows you to charge faster, cheaper and greener. It is also the safest way to charge your EV at home. Here we take you through our pre-installation checks to ensure you're always charging safely.

At a Glance

How your pre-installation checks help Egg to ensure your EV charger can be installed safely

How Egg can help you to get ready for your EV charger installation

There’s no denying charging your EV at home is the most convenient way to charge your electric car. Just park up, plug in and head into the comfort of your own home to recharge yourself. But did you know having a dedicated EV charger is also the safest way to charge your EV at home?

A standard 3-pin plug can be used to charge your EV in an emergency, but they are not designed to support the load needed to charge a car, especially for the length of time required. Home EV chargers are made just for this, and although they have safety features built in we need to ensure they are installed correctly to protect you, your home and your electric car.

To do this we will ask you some quick questions as part of your pre-installation checks, here we will take you through what we are looking out for to ensure a safe installation.

Why do you need photos of my water & gas supplies?

These photos help us to see if your gas and water supply pipes are metal or plastic (non-extraneous). If they are metal then ‘bonding’ is required to ensure that you are safe from the risks of electric shock in the event of a fault. If your pipes are metal we need to be able to see if you already have a bonding clamp attached to the pipes with a green & yellow cable connected. These cables should go back to your consumer unit or electricity supply where they will be connected to a main earthing terminal MET.

If your pipes are metal and we cannot see any sign of bonding in your photos, we will need to carry out further checks to confirm if bonding is or isn’t present.

If we can confirm bonding isn’t present, this will need to be installed before your EV charger is fitted to comply with Wiring Regulations and ensure your safety.

You can have your own electrician carry out the bonding prior to the EV charger installation if you prefer as long as you can send us photos of the new bonding in place.

What is bonding?

Bonding, correctly know as Main Protective Bonding must be installed to provide protection against electric shock in the event of a fault. This is achieved by linking metallic pipework such as the gas and water pipes to the Main Earthing Terminal MET for your property which is commonly inside your consumer unit but can be on a separate metal connection bar usually near to the meter, In your home this should be 1cm green and yellow conductors, these are connected to the pipes using earth clamps and should be within 60cm after the water stopcock or on the customer side of the gas meter. The clamps can be identified by a metal label that states ‘Safety Electrical Connection – Do not Remove’. On older installations the bonding cables may be green only and are often undersized, if this is the case upgrading would be required to ensure it complies with the current Wiring Regulations.

What do you mean by non-extraneous?

In the electrical world we refer to metallic pipes as extraneous and plastic or insulated pipes as non-extraneous. We need to confirm whether the gas, water or oil pipes in your property are extraneous (metal) or non-extraneous (plastic or insulated) to confirm if bonding is required.

Why can’t you install the charger from my fuse board?

If we have said we cannot install your EV charger from your fuse board or consumer unit this can be for a few reasons:

  • The consumer unit doesn’t comply with the current Wiring Regulations, specifically as regards the fire integrity of the board. From 2017 all consumer units in homes must be manufactured from non-combustible materials. All modern consumer units are made from metal and are designed to prevent the spread of fire by containing any fire inside the board as a result of arcing or overheating.

  • An EV charger is likely to be used at full load for a long period of time, often overnight. With the fairly high load and duration of the charge there is the possibility that connections can heat up, therefore to avoid the low inherent risk we only install from fire rated consumer units.

  • The existing RCD’s in the consumer unit are Type AC and are obsolete, EV chargers need to have earth leakage protection provided by type A RCD’s.

  • There are no spare ways available.

  • The existing installation appears to be in poor or unsafe condition.

Why do I need to have a Main Switch installed?

Where we cannot come from your consumer unit we will need to be able to install from the electricity supply position, to enable us to do so we need to be able to isolate the supply so that we can work safely.

I have a main switch already, why do I need another one?

Where we cannot come from your consumer unit we will need to install from the electricity supply position, the main switch at your consumer unit only isolates circuits fed from it and not the supply to the property; therefore a main switch requires installing at the supply position to enable us to isolate and work safely.

I need groundworks for my EV charger installation, can I do these myself?

Yes you can, though you will need to follow guidance. Buried cables and ducts shall be at sufficient depth to avoid being damaged by any reasonably foreseeable disturbance of the ground, in normal domestic areas such as a garden we recommend a depth of approximately 300mm. The cable used to supply the EV charger isn’t armoured therefore needs to run into a duct to provide mechanical protection. We recommend that it should be approx. 50mm. A draw rope will need to be run into the duct for us to use to pull in the cable. Sharp bends should be avoided and the ends need to be as close to the walls as possible. Ensure the ends of the ducts are temporarily sealed.

Can my EV charger be installed on my fence?

Unfortunately not, the EV charger needs to be installed on a solid masonry wall.

What is a looped supply?

A looped supply is the term used to describe when the electricity supply to your property is looped to a neighbour's property, meaning both properties are fed from one supply. This was satisfactory when installed however with ever increasing demands, it may be necessary for the Electricity company to carry out works to ensure that their network can cope with the additional load. This isn’t dangerous and is nothing for you to worry about and you aren’t paying for your neighbour's electricity.

What is trunking?

Trunking is used to contain the cable where it is routed through your property and is manufactured from white PVC. The size of the trunking will depend on the route and how many bends are required, for a straight run this will be around 40mm x 25mm, for routes with bends this will be 50mm x 50mm. The trunking can be painted following installation.

What is a comms cable?

A comms cable is a data cable such as CAT5 that is routed from the EV charger to the meter position, this is used to monitor the electricity demand of your property. The charger is designed to reduce the charge rate at times when a large amount of electricity is being used in your home, this is to prevent the rating of the electricity company fuse from being overloaded.

Can my charger be installed in my garage or a detached building?

In some cases we may be able to install to a building or structure that isn't where the electricity supply enters the property. In most cases however, this wouldn't be possible. As our chargers monitor the main incoming supply to ensure you get the fastest available charging speeds, the existing cables that have already been installed to power the separate building or structure may not be sufficient. In these cases, there may need to be a new cable installed underground or run from the electricity meter to the charger location.

If you're unsure and need some guidance, get in touch with our team who will be happy to advise you of your options, before you place an order.

I have an old EV charger that will be removed, can I re-use the cable for the new charger?

This will depend on the type of cable, how it is installed and where it is fed from, this will need to be reviewed by our Quality team.

Why do I need a main switch when my solar panels were installed without one?

We cannot comment on how a previous contractor may have isolated the supply to allow safe working. If we have asked for a Main Switch to be installed this means that there is no other safe way of isolating the supply to enable us to work safely.

How big is the cable that will supply my charger?

The external diameter of the cable is approximately 15mm.

What is an RCD / RCBO?

These are safety devices that monitor for any current leakage to earth and are designed to trip within 40millisecond to protect against electric shock. A home EV charger must have this protection.

Why do you need a floorplan of my home?

On your floorplan we ask you to show:

  • The position of the meter / cut-out

  • Consumer unit

  • Preferred EV charger position

  • Suggested cable route

This is an invaluable aid to us when assessing your photos to establish suitability for the installation of the charger. The more information we receive at the self-survey stage will help improve your customer experience.

Is there a minimum / maximum height that the charger should be installed at?

The actual socket should be between 0.75M and 1.2M above ground level.

I have external wall insulation (EWI) installed can I still have an EV charger installed?

Due to the difficulty in getting satisfactory fixings on external wall insulation we won’t install where this is the case.

Can I have one or more EV chargers installed?

Yes you can, we would need to know how you intend to use your EV chargers and may need to complete a DNO Application to the electricity company for your supply cut-out fuse to be upgraded, please note that this will delay the installation of the chargers.

What is a DNO application?

A DNO application is required where the supply to your property is looped; we see very old potentially dangerous equipment or the cut-out fuse requires upgrading to cope with the additional load of an EV charger.

Don’t worry, we complete the application on your behalf. The DNO are the Distribution Network Operators (electricity company) that are responsible for the electricity network. They review all applications and may contact you to arrange site visits to assess for any further works that may be required, any upgrading works are usually free of charge. The demand on DNO’s is very high and as such any application can delay the installation of your charger.

What is an EIC / EICR?

  • EIC – Electrical installation Certificate – used to provide test results for a new circuit and includes supply characteristics such as bonding details.

  • Electrical Installation Condition Report – used to report on the condition of an electrical installation and also includes supply characteristic such as bonding.

We ask for copies of these where it has not been possible to confirm the presence of bonding from photos, we will accept these reports as confirmation of bonding.

You will also be issued an EIC for the works carried out to install your EV Charger.

What is an Earth Rod?

Usually the electricity companies provide an earth, however there are instances where they cannot guarantee a satisfactory earth connection, where this is the case it is the home owners responsibility to provide a private earth connection. An earth rod is a 1.2M copper plated rod that is driven in to the ground just leaving the top section exposed often on the outside of the property near where the electricity meter is, this should have a green & yellow cable attached to it by a clamp, the cable will go to your consumer unit or main earthing terminal MET. The connection of the earth cable to the earth rod may be inside a plastic enclosure. If we cannot see an earth connection to the electricity company supply we will ask for a photo of the earth rod to ensure that your property is suitably earthed.

What is Maximum Demand (MD)?

When we carry out a DNO application on your behalf we need to provide the maximum demand; this is the calculated maximum current demand which we collate by asking you a few simple questions such as; do you have an electric cooker. If the demand is high we would also ask the electricity company for a supply fuse upgrade to ensure that the installation of the EV charger will not take the total demand above the rating of the supply fuse.

For any more questions you have about installing a home EV charger with Egg get in touch

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