How to Terminate a Cable Lug onto an Earth Bar

How to Correctly Terminate a Cable Lug onto an Earth Bar

The correct way to terminate the Cable Lug onto an Earth Bar seems to cause confusion in the industry. For instance, a very common question we hear is: should the cable lug be bolted face down directly onto the actual copper bar or should the cable lug be placed ‘floating’ between the nuts? This article from A.N. Wallis aims to highlight the recommended connection instructions that eliminate the common mistakes being made during installation and termination of a cable lug on an earth bar.


Earth Bar Termination Components

Before talking about the correct installation, it is important to look at the actual termination components of the Earth Bar and know what these are:

Earth Bar Termination Components

Each typical AN Wallis ‘standard’ termination point consists of the following components:

  • 1a No. x M10 x 35 Phosphor Bronze Hex Head Set (7)
  • 1b No. x M10 Phosphor Bronze Flat Washer (4)
  • 1c No. x M10 Phosphor Bronze Spring Washer (8)
  • 2 No. x M10 Phosphor Bronze Full Nuts (5)

When manufactured, the combination of components are assembled on an Earth Bar in the following order:

Hex Head Set → Flat Washer → Nut → Spring Washer → Nut


Recommended way to terminate a Cable Lug onto an Earth Bar

Correct way: how to terminate a cable lug onto an earth bar

To begin with, our recommended way for the termination/ installation/ connection of the cable lug onto an Earth Bar is to ‘fix’ the flat side of the cable lug directly to the actual copper bar. This method allows for full contact between the connecting cable and the Earth Bar and prevents any reduction in cross-sectional area. Therefore, based on the components supplied on a AN Wallis Earth Bar, we recommend the ‘fixing’ to be made in the following combination (as detailed in the below picture)

  1. Lug over the Hex Head Set (in direct contact with the Copper Bar)
  2. Flat Washer
  3. Spring Washer
  4. Nut
  5. Nut

Under normal circumstances, when fixing down a cable lug having the spring washer and one nut should be absolutely fine. However, AN Wallis like to go above and beyond therefore they supply two nuts! The second nut acts as a lock against the first nut, making the installation even more tight, secure and safe.


Incorrect way to terminate a Cable Lug onto an Earth Bar

Incorrect way: how to terminate a cable lug onto an earth barThere are occasions where people incorrectly assume that the supply of two nuts must be used to ‘sandwich’ the lug in between the two. For example, the lug ‘sitting’ on one nut and tightened up by the other. This is not correct and not recommended at all! This method does NOT allow full contact to be made between the connecting cable and Earth Bar, therefore the actual cross-sectional area is reduced.

We can think of two reasons to use this incorrect method – Firstly, it could be a lack of knowledge/training on the correct installation procedures. Secondly, it could be ‘laziness’ of the installation contractor, wanting to save some time and effort by not fully disassembling the termination components to attach the lug and reassemble correctly. This may save slight installation time, but it is incorrect and more importantly, unsafe!

In conclusion, the recommended way for the termination/ connection of the cable lug onto an Earth Bar is to ‘fix’ the flat side of the cable lug directly to the actual copper bar. That way the cable lug is directly in contact with the actual copper bar. This method allows for full contact between the connecting cable and the Earth Bar and prevents any reduction in cross-sectional area.


A.N. Wallis Earthing Solutions

AN Wallis designs, manufactures and supplies thousands of Earth Bars per year, it is one of their core products ranges. This have given them many years of expertise and experience dealing with Earth Bars and puts them in a good position to answer any questions or queries on the topic of Earthing Protection & Earth Bars. Apart from the bars, they also offer a wide range of Earthing Protection products & solutions:

Earth Bars - Earthing Busbars - AN Wallis

EARTHING BARS

Earthing Earth Ground Rods

EARTH RODS

Grounding Clamps -Rod Clamps - Bonding Clamps - U-Bolt Clamps

EARTHING CLAMPS

Rod-Couplers-Threaded-Couplings

ROD COUPLERS

wallis driving heads

DRIVING HEADS

Earth-Accessories

ACCESSORIES


Have you read our article: What is Earthing/ Earthing System?

E-Tech will answer any questions you have regarding this range or any products needed for your project.

For additional information, contact us at:
sales@etechcomponents.com or +44 (0)1744 762 929

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