Good morning to all. Revisiting a surge issue please.
Imagine a final circuit (or it could be some equipment cabling e.g to radio mast but Im not familiar so prefer to use a final circuit as the example ) that is fed from a [upfront] SPD protected board . The circuit runs back outside (across a zone boundary? ), overhead/buried, for some distance (e.g 100m or whatever) to equipment that is in contact with earth.
- is it true that circuit could introduce a ‘surge' back into the installation just as the DNO supply may at the origin ?
- in such a case if true, would there need to be another SPD after the final circuit's OPD to cater for this **… or if not where would the SPD(s) go and across which conductors ?
- what ‘surge’ levels coming back in to the installation might one expect ?
e.g. origin----SPD---DB/CU outdoor circuit OPD--- **additional SPD ------ overhead/buried run (100m) ---- [grounded?] outdoor equip (poss with local SPD)
Sorry in advance if I am not understanding well enough to ask a coherant question ! :-)
Thank you, Habs
