Member
Posted September 10, 2015
We can't always test cable in free air, sometimes it might be down in a hole or in a cabinet. My question is what is the minimum distance I need to keep my cables from arcing when testing with high voltage?Someone once told me a good rule of thumb is 1" per kV, is this correct?
Junior Member
Posted September 10, 2015
It depends on the voltage, really. I believe what you were told, 1ft. per kv, is more than enough to keep you and whatever equipment around you safe.
Member
Posted September 16, 2015
You must have misread my post, I was told 1 inch per kV not 1 foot.
Junior Member
Posted September 16, 2015
You know what's funny, I was thinking about this the past couple of days. I did misread this, haha, but 1" per kV.. I don't know. I'd feel more comfortable with ~2". This is just my safe take on this. I should assume that some company has this set in stone. I'll do some research and get back to you on that.
Junior Member
Posted September 21, 2015
Man, I can't find anything on this. I did manage to find some paperwork about cable insulation when using electrical tape. As far as bare cable to cable, I asked multiple people with 20-30+ years and they told me they just go off what they feel comfortable with. I'll continue to look, but as far as set in stone goes, I wouldn't say there is anything.
NETA Level III
Posted September 21, 2015
Pro Subscriber
After using the Google machine I was able to find a pretty interesting paper that references 1 inch per 10 kV for bare conductors in free air:
With bare conductors, air is the insulator, and clearance distances can be calcuated using standard values for the breakdown of air. A common rule of thumb which is very conservative is 1 inch per 10 kV. Since the breakdown field for air is around 71 kV/inch, this provides a 7:1 safety factor.
http://home.earthlink.net/~jimlux/hv/hvwire.htm
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