Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here


Armor Grounding - If not used as earthing conductor

Armor Grounding - If not used as earthing conductor

Armor Grounding - If not used as earthing conductor


for a low voltage, single core three phase plus neutral system:
If the armor of the cable is not used as the earth conductor, (instead a separate conductor is connecting load and source panel to the earth grid),

What is the IEC requirement about grounding the armor (when it is not used as earthing conductor)?

My opinion is to ground the armor on one side, but I don't have any backup. I have searched online but could not find a specific answer.
While the opposite opinion is to insulate the armor at both sides as there is no need to ground it.

Is there any IEC requirement to ground the cable armor regardless of its being used as earth conductor or not!!

the cable is CU/XLPE/AWA/PVC

Thanks in advance.

RE: Armor Grounding - If not used as earthing conductor

Just an opinion. If a hot wire shorts to the armor (say a nail is driven thru the cable)and the armor is not grounded, you have a Hot armor.

RE: Armor Grounding - If not used as earthing conductor

The armor may be considered a raceway and a raceway must be grounded at the source end.
Normal practice is to ground the armor at the supply end.
For single conductor ground the armor at the supply end and isolate at the load end.
This is to prevent induced current flowing in the armor.
For multi-conductor cable both ends may be grounded but there must be a grounding conductor included in the cable and it must be grounded.
For spiral armor that has been in service for awhile, a fault current in the armor will tend to flow around the spiral rather than passing from wrap to wrap.
In such a case there are two possibilities.
1. The armor may act as a spiral heating element.
2. The resistance and the impedance or the spiral may be too high to trip the over-current protection and may even be too high to trip the overload protection.

"Why not the best?"
Jimmy Carter

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


eBook – How to Choose the Correct Corrosion Testing Method
When designing a metal component, engineers have to consider how susceptible certain alloys are to corrosion in the final product’s operating environment. In a recent study by NACE (National Association of Corrosion Engineers), it was estimated that the direct and indirect costs of corrosion in the United States is approximately 6.2% of the GDP. In 2016, that cost exceeded $1 trillion dollars for the first time. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close