Lightning Arrestor Help
Lightning Arrestor Help
(OP)
For a job we are looking at installing a lighting suppression system, but my company has no information or previous experience with such jobs.
The system in question is an ungrounded 4160V, stepped down from a 2500 kVA Wye Primary, Delta Secondary Transformer, that feeds several buildings up to 2000 FT away.
What I have gathered so far is that we need an arrestor good for about 33kV, or about 10. p.u of the L-L voltage. It will be a Metal Oxide (MOV) type as well.
I have also read that the valid protective distances for arrestors are something to the effect of several miles, so we could in theory get away with a single set of arrestors per building feeder, however one at the transformer and 1 at the building (reflection point) would be best.
Is there anything else I need to know about this? And is my game plan at least correct in theory?
The system in question is an ungrounded 4160V, stepped down from a 2500 kVA Wye Primary, Delta Secondary Transformer, that feeds several buildings up to 2000 FT away.
What I have gathered so far is that we need an arrestor good for about 33kV, or about 10. p.u of the L-L voltage. It will be a Metal Oxide (MOV) type as well.
I have also read that the valid protective distances for arrestors are something to the effect of several miles, so we could in theory get away with a single set of arrestors per building feeder, however one at the transformer and 1 at the building (reflection point) would be best.
Is there anything else I need to know about this? And is my game plan at least correct in theory?






RE: Lightning Arrestor Help
RE: Lightning Arrestor Help
The other rule is to run generously sized ground wire from the arrester directly to earth (and transformer tank) with as few bends as possible.
RE: Lightning Arrestor Help
Are the 4160V feeds to the buildings overhead or underground?
RE: Lightning Arrestor Help
So when you say an arrestor for each device, you mean 1 for the Trans and 1 for the building? (technically 3 for each as there are 3 phases right)?
So 5.1 kV? Is there any book or through online resource that discusses this? I have a feeling I need to see some equations to get a better handle on this.
RE: Lightning Arrestor Help
PROTECTION OF DISTRIBUTION SYSTEMS, Ohio Brass.
RE: Lightning Arrestor Help
If you want lightning protection for the building, that's another story entirely.
RE: Lightning Arrestor Help
Just an inquiry, if your requirement is a building lightning protection, how do you install the downconductor (say 25 storey building). Is it encased in a pipe sleeve and embedded in the column? If so, how do you account for the splicing of the downconductor?
Thanks
RE: Lightning Arrestor Help