Electrical Vehicle Charging Points – Earthing without rods: safer, faster and more effective earthing

Earthing Services saves time, money and lives for its clients. Adapting technology that has saved millions of pounds for one of the world’s largest telecoms companies, with Conducrete and the ConduDisc Earthing Services can increase the reliability of your metering and distribution pillars. Conducrete and ConduDisc solutions dramatically enhance earthing performance over traditional methods; they are very strong and reliable, environmentally neutral and incredibly fast to install.

The challenges of earthing for domestic EV charging points

  • With the arrival of the 18th Edition Wiring Regulations domestic charging points require an independent earth at a sufficiently low resistance.
  • In order for some EV chargers to function at all a low resistance to earth must be achieved, which is a prudent safety precaution in the event of a fault.
  • Some ground types which have an inherently low resistance can prove aggressive to conventional metallic components, the consequence of this is that as time passes the earthing provision will deteriorate and resistance will increase. Deteriorating earthing systems could prove damaging to a company’s reputation.
  • Unless there is an area of grass or soil it may be impractical or impossible to install a network of metallic conductors.

earthing in a small footprint and shallow excavation

How can these challenges be overcome?

  • Our Conducrete and ConduDisc systems do not require extensive footprints to function effectively.
  • Highly adaptable and suitable for shallow excavations.
  • Conducrete and ConduDisc will protect against theft and corrosion; as such it will avoid deterioration of system components and any loss of performance.

Would the same approach work for commercial installations?

Absolutely. The methods and products work on any variety of earthing system.
Charging Point Model

Why not earth rods?

  • Time consuming to install.
  • Inner cities often have problems with unmarked, or relocated services, which is a problem when driving earth rods blindly.
  • If sub surface rock, or concrete is encountered driving electrodes may not be possible.
  • Not all services can be identified using Cable Avoidance Tools.
  • Relatively small contact surface area with surrounding earth, which impedes earthing performance.
  • Whatever variety of metal conductor used it will be subject to corrosion and is likely to require maintenance.

Why Conducrete or ConduDisc?

  • Incredibly fast and easy to install.
  • Conducrete/ConduDisc sits within the normal foundation excavation so no driving is required.
  • No special excavation or time consuming drilling methods are needed to install Conducrete or ConduDisc.
  • No special survey equipment is needed.
  • Large contact surface area with surrounding earth to enhance earthing performance.
  • Conducrete has a minimum 40 year service life, whilst the ConduDisc has a service life up to 60 years, even in demanding environments and both are maintenance free.

Aren’t all earthing backfills the same product with a different name? Absolutely not.

conducrete

A common misconception is that all earthing enhancement backfills are the same product with a different brand name, whilst this is true for many it is certainly not true for Conducrete. Independent laboratory data (as can be seen on the Conducrete product page here) evidences how much more effective it is over other products of its type; if you are using a different product and want to check ask the supplier for the independent laboratory data that proves its performance. Furthermore unlike nearly every other product it does not require any additive, and in many applications does not even require water. Instead of having to arrange for cement mixers and water sources many customers use the product in its dry form, ensuring that it is encapsulated with native soil in an undisturbed layer and over the course of 28 days it will fully harden and achieve a more representative resistance performance. From large utilities to independent contractors companies all over the world have achieved incredible performance improvements and total cost of ownership savings by using Conducrete as their method of creating an earthing system.

Versatile range of Conducrete and ConduDisc solutions

There are many versatile earthing methodologies using these products, and all of them achieve the following:

  • Lower service life cycle cost
  • Improved electrical performance
  • Reduced copper theft
  • Almost eliminates electrode corrosion
  • Practical to install

ConduDisc

  1. Place a ConduDisc within the excavation of the foundation for the distribution pillar and place a duct over the 50mm² (size subject to confirmation based on requirements of system) copper interconnection conductor.
  2. Backfill with native soil to cover the ConduDisc and compact. The conductor is effective immediately.
  3. Complete Backfill as normal. Ensure that the ground mounting base is secure and the ConduDisc interconnection cable duct visible.
  4. When installing the distribution pillar use a crimp-type connector to secure the pillar earth conductor onto the interconnection conductor within the duct and complete surface finishing.

 

 

The Conducrete “sub-base” approach

DSLAM2

 

As EV charging stations are frequently retrofitted there may not be a large area to install conventional earthing conductors.

Using Conducrete beneath foundation slabs is a highly effective, cost-efficient and practical way to achieve a reliable resistance within a shallow excavation and within a restricted footprint. This “sub-base” approach has been enormously popular with every client that has adopted it.

This approach is useful for all manner of varieties of infrastructure and because it doesn’t require any additional plant, equipment or specialist training it removes unnecessary additional costs, time-consuming methods, or standing time on site.

This common Conducrete earthing methodology can be seen on a real project in the following images:

 

 

 

“Sub-base” installation overview

In applications where a foundation is required for telecoms, signalling or other infrastructure element dig an extra 50mm.

1. In applications where a foundation is required for telecoms, signalling or other infrastructure element dig an extra 50mm in the excavation.

Place the required number of bags of Conducrete in the excavation.

2. Place the required number of bags of Conducrete in the excavation.

3. Carefully empty the bags of Conducrete into the excavation. As the product is a fine powder appropriate PPE should be worn. We recommend using a craft knife along an edge and then carefully dispersing the product to an equal depth.

3. Carefully empty the bags of Conducrete into the excavation. As the product is a fine powder appropriate PPE should be worn. We recommend using a craft knife along an edge and then carefully dispersing the product.

4. Ensure that the Conducrete is evenly dispersed.

4. Ensure that the Conducrete is evenly dispersed.

5. Place injection current cable into the Conducrete. This is usually a 16mm² copper wire loop with a tail to be placed in a duct to the infrastructure earth point, and tails for any adjacent earthing configuration (see image 8).

5. Place injection current cable into the Conducrete. This is usually a 16mm² copper wire loop with a tail to be placed in a duct to the infrastructure earth point, and tails for any adjacent earthing configuration (see image 8).

6. Ensure that the injection cable is fully submerged within the Conducrete (with the exception of any to be located in ducts). This will protect the cable against corrosion and theft.

6. Ensure that the injection cable is fully submerged within the Conducrete (with the exception of any to be located in ducts). This will protect the cable against corrosion and theft.

7. Redistribute any displaced Conducrete to ensure that it remains evenly distributed.

7. Redistribute any displaced Conducrete to ensure that it remains evenly distributed.

8. Place Conducrete in any interfacing trench; these are commonly excavations for interconnecting ducts.

8. Place Conducrete in any interfacing trench; these are commonly excavations for interconnecting ducts.

9. Carefully distribute Conducrete in the interfacing trench.

9. Carefully distribute Conducrete in the interfacing trench.

10. Ensure that the Conducrete in the interfacing trench is evenly distributed.

10. Ensure that the Conducrete in the interfacing trench is evenly distributed.

12. Carefully reinstate a layer of native soil. The Conducrete will start to harden as it comes into contact with the native soil, but care should be taken to avoid mixing the layers (a way of thinking of this approach is like forming layers in a trifle). Once a complete layer of native soil covers the Conducrete the area should be manually tamped/compressed.

11. Carefully reinstate a layer of native soil over all of the installed Conducrete. The Conducrete will start to harden as it comes into contact with the native soil, but care should be taken to avoid mixing the layers (a way of thinking of this approach is like forming layers in a trifle). Once a complete layer of native soil covers the Conducrete the area should be manually tamped/compressed.

The advantages of this methodology over conventional methods are:

  • Incredibly fast
  • Incredibly easy
  • Incredibly effective
  • Avoids the use of rods
  • Unlike other earthing enhancement backfills it does not require any additive or even water for this methodology; this means no need for mixers or any other specialised plant equipment.

 

Conducrete and ConduDisc are easier to use, faster to install and more reliable than conventional earthing methods. To learn more about Earthing Services’ electrical vehicle (EV) charging points earthing solutions please feel free to get in touch through the contact page of this website or calling the office.