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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
  • Former Community Member
    0 Former Community Member

    Sparkingchip:


    So how do I risk assess 25 yo 30 metres of overhead telephone cable or do I just use a telephone line SPD regardless?


    A bit back when I was watching German SPD installation videos on YouTube they were including telephone line SPDs, but I have not noticed the manufacturers promoting them in the UK.


    Andy B.




    40 odd years ago I made my own SPD for the telephone line after the fax and answer phone blew up for the third time. I suppose living at 1000ft above sea level I should have expected it. We never had any problems with the OH mains supply?

     

Reply
  • Former Community Member
    0 Former Community Member

    Sparkingchip:


    So how do I risk assess 25 yo 30 metres of overhead telephone cable or do I just use a telephone line SPD regardless?


    A bit back when I was watching German SPD installation videos on YouTube they were including telephone line SPDs, but I have not noticed the manufacturers promoting them in the UK.


    Andy B.




    40 odd years ago I made my own SPD for the telephone line after the fax and answer phone blew up for the third time. I suppose living at 1000ft above sea level I should have expected it. We never had any problems with the OH mains supply?

     

Children
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