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 16 replies
  • Subscribers 38 subscribers
  • Views 2445 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

Do I need to do anything about single pole Isolator owned by DNO

Alan B

I was changing a consumer unit today on a property where there was an isolator supplied by the DNO (owned by _______ molded in to it) but it was only single pole. The supply was TNCS and the consumer unit has a double pole isolator. The property is about to be put on to the rental market.

My initial thought is that the double pole isolator switch in the CU provides the isolation function and its a TNCS supply with limited risk of dangerous voltages on the Neutral. Therefore the single pole isolator upstream of the CU isn't ideal but not immediately dangerous and I should just note it on the installation certificate.

Or should I be highlighting the problem to the owner and suggesting they contact their DNO to request a change and what is the likely response from the DNO?

Looking forward to your views and advice.

Thanks

Parents
  • 0

    I just had another quick look on YouTube for the IET video, but cannot see it.

    It prompted me to buy a single pole contact voltage indicator, I used it a few weeks ago when I did a call out for a gas contractor replacing the old metal gas mains pipework with plastic, they disconnected the old steel gas pipe and the meter became live as did everything else that should have been earthed in the house, because the old gas main was the earth electrode for the TT installation.

    Do not trust either a single or double pole switch to truly isolate an electrical installation.

Reply
  • 0

    I just had another quick look on YouTube for the IET video, but cannot see it.

    It prompted me to buy a single pole contact voltage indicator, I used it a few weeks ago when I did a call out for a gas contractor replacing the old metal gas mains pipework with plastic, they disconnected the old steel gas pipe and the meter became live as did everything else that should have been earthed in the house, because the old gas main was the earth electrode for the TT installation.

    Do not trust either a single or double pole switch to truly isolate an electrical installation.

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