Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 11 replies
  • Subscribers 33 subscribers
  • Views 2330 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Earthing system

Pompey boy

Recently mobile welfare cabins with integral generators were used on site.

Test sheets supplied gave the earthing system as IT. 

2 phase 3 wire

NO earth electrode was used when the suppliers tested before arrival on site.

On arrival on site an earth electrode was installed and the cabin was connected to this.

Is the cabin now a TT system?

Parents
  • 0

    It won't be TT unless there are two separate electrodes - one for the source (generator) and another for the consumer.

    The usual arrangement for generators is TN-S with the local electrode serving as the source electrode (like the one that's at the substation in a public supply), or for small systems (e.g. <3kVA) a separated system is sometimes used (neither the source nor exposed parts of the installation deliberately connected to an Earth electrode).

    IT is a possibility - especially if someone has connected the installation's exposed-conductive-parts to the electrode without creating a N-PE link. Whether that's the best choice is another matter (IT systems are usually chosen where resilience on first faults is needed - and normally include insulation monitors and warning systems).

       - Andy.

Reply
  • 0

    It won't be TT unless there are two separate electrodes - one for the source (generator) and another for the consumer.

    The usual arrangement for generators is TN-S with the local electrode serving as the source electrode (like the one that's at the substation in a public supply), or for small systems (e.g. <3kVA) a separated system is sometimes used (neither the source nor exposed parts of the installation deliberately connected to an Earth electrode).

    IT is a possibility - especially if someone has connected the installation's exposed-conductive-parts to the electrode without creating a N-PE link. Whether that's the best choice is another matter (IT systems are usually chosen where resilience on first faults is needed - and normally include insulation monitors and warning systems).

       - Andy.

Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines