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 32 replies
  • Subscribers 27 subscribers
  • Views 1038 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

my surge protection 'cpd', such as it is...

psychicwarrior
Good morning all


I have obtained the following [I feel as the] 'best we can do for now' information from the DNO. They were helpful in my test case request for info.


"...address 1:

LV underground - 362m

HV underground to primary-  2000m

No Surge protection devices


address 2:

LV underground to substation - 110 m

HV UG from substation to HV pole is 823m then 301m 11kV overhead then 190m HV UG to the primary substation.

Distance to cable termination with surge protection device from secondary substation is 1124m (823m 11kV UG + 301m 11kV Overhead).  The nearest cable

termination does not have surge protection installed. ..."


In relation to the risk assessment equation variables dealing with distribution cable lengths  ie. the Lpal Lpcl Lpah Lpch, how would one fit the given values into the variables ?


For addr1, ignore the HV (e.g. use zero for Lpah Lpch),  then take Lpcl as 362 and Lpal as 638 ?


For addr2, i'm not sure on this one ?


Thanks for your input.

Habs


Parents
  • 0
    AJJewsbury‍ gkenyon‍ Thank you for plumbing the figures in - especially in addr2 scenario.  In addr1 I made a daft mistake, presuming that the HV should be ignored and that the difference left from taking the underground LV away from 1km, was to be attributed to some assumed overhead LV part...when in fact of course, there is not one declared by the DNO - so as you have done, it had to be attributed to the underground HV they detailed. I've not said that well I dont think, but I have understood your approach.


    There are boards being supplied with SPD as Sparkingchip‍ pointed out and that is useful, but this was more about trying a real world-ish scenario. I'm glad I asked here about it...thanks again.


    Interesting re: the phone line concerns - perhaps all one can do, given it belongs to the phone company up to the master socket and is not BS7671, is advise the client that it too needs looking at and to contact the supplier to have it assessed - or can someone fit something themselves without messing with the master socket - will have to have a read. Then there is fibre (dependng on construction materials) to consider...Or is it really immune as one might think.


    Thank you all again.
Reply
  • 0
    AJJewsbury‍ gkenyon‍ Thank you for plumbing the figures in - especially in addr2 scenario.  In addr1 I made a daft mistake, presuming that the HV should be ignored and that the difference left from taking the underground LV away from 1km, was to be attributed to some assumed overhead LV part...when in fact of course, there is not one declared by the DNO - so as you have done, it had to be attributed to the underground HV they detailed. I've not said that well I dont think, but I have understood your approach.


    There are boards being supplied with SPD as Sparkingchip‍ pointed out and that is useful, but this was more about trying a real world-ish scenario. I'm glad I asked here about it...thanks again.


    Interesting re: the phone line concerns - perhaps all one can do, given it belongs to the phone company up to the master socket and is not BS7671, is advise the client that it too needs looking at and to contact the supplier to have it assessed - or can someone fit something themselves without messing with the master socket - will have to have a read. Then there is fibre (dependng on construction materials) to consider...Or is it really immune as one might think.


    Thank you all again.
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