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 32 subscribers
  • Views 2637 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can 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

    534.4.1.3 (cryptically).


    ... overhead lines (including LV) are not unknown to suffer direct strike, and therefore "or protection against the effects of direct lightning" may well apply.



    I did wonder about that, but I ended up reading it as:


    "and the structure is equipped with ... protection against the effect of direct lightning..."


    i.e. the structure has some kind of system to protect it against lightning that isn't strictly an 'external lightning protection system' (not sure what that might be - maybe a steel structure that acts as its own lighting rod?).

    So I read it as when the structure has protection, rather than when it's in need of protection.


    Cryptic indeed! It does seems sensible though.


       - Andy.
Reply
  • 0

    534.4.1.3 (cryptically).


    ... overhead lines (including LV) are not unknown to suffer direct strike, and therefore "or protection against the effects of direct lightning" may well apply.



    I did wonder about that, but I ended up reading it as:


    "and the structure is equipped with ... protection against the effect of direct lightning..."


    i.e. the structure has some kind of system to protect it against lightning that isn't strictly an 'external lightning protection system' (not sure what that might be - maybe a steel structure that acts as its own lighting rod?).

    So I read it as when the structure has protection, rather than when it's in need of protection.


    Cryptic indeed! It does seems sensible though.


       - Andy.
Children
No Data

Community Rules & Guidelines