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 2 replies
  • Subscribers 32 subscribers
  • Views 328 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

Risk assessment for spd,s in domestics.

hertzal123
Just checking my calcs for requirement for spd in a suburban area,fenv =85.Don,t know length of supply cable so Lp =1 and ng for my area

is 0.3,so using fenv/Lp x Ng gives a risk assessment figure of about 283,indicating a spd is required because its under 1000.So does this indicate

that most suburban domestic installations require spd,s?The suburb is only a mile from a town.Thanks for any replies.

                                                                                                    Regards,

                                                                                                               Hz
  • 0
    Yes, effectively. I think that I live in a suburb, but I couldn't tell you where it ends and the urban bit starts. We are almost rural with an airfield 1/2 mile away, but how is that classified - there are WW2 sheds as well as recent industrial units and yet more housing? At the far side, cross the road and you are in fields.


    Daughter's house is unequivocally rural - all overhead and transformer up a pole.


    I would like to say that the centre of London is unequivocally urban, and it may well be within the Congestion Zone, but what about Buckingham Palace? ?


    I cannot help feeling that there should be three fenv: one for urban, one for suburban, and one for rural.
  • 0
    That's only if you assume the worst about the supply cable. Normally you'll have a rough idea whether the supply to the house is over/under ground, how far away the nearest substation is, whether the HV supply to that substation is over/underground and for that matter whether there appear to be any LV or HV poles/pylons anywhere near, via Google maps.

Community Rules & Guidelines