Naked Science Forum

Non Life Sciences => Technology => Topic started by: The Scientist on 02/06/2011 08:58:36

Title: Is it dangerous to make a phone call when there is lightning?
Post by: The Scientist on 02/06/2011 08:58:36
Can anyone please share their experiences or knowledge on the matter? Many Thanks!
Title: Is it dangerous to make a phone call when there is lightning?
Post by: grizelda on 07/06/2011 08:36:34
The modular wiring which connects most phones would seem too light gauge to carry a substantial current. It would likely instantly vaporize, like a fuse.
Title: Is it dangerous to make a phone call when there is lightning?
Post by: CliffordK on 07/06/2011 09:17:22
I think I'd agree...  both your household phone wiring and the wiring inside of the phone would fail before there would be a great risk to yourself.  It would also be a fairly high resistance path to jump through the phone to your ear and down through your body to the ground, although a phone sitting on a non-conductive table wouldn't necessarily be a shorter path.

There would be no risk with a cordless phone or a cellular phone.
Title: Is it dangerous to make a phone call when there is lightning?
Post by: Geezer on 07/06/2011 18:46:42
The condutors in internal phone wiring are quite capable of carrying enough current to kill you. Fortunately, the insulation is not that great, and that limits the voltage.
Title: Is it dangerous to make a phone call when there is lightning?
Post by: SeanB on 07/06/2011 21:56:43
I lived in a town where the district lines were hit by lightning 40km or so outside town. Every phone on the exchange rang once as the lightning destroyed the entire exchange, so badly it was scrapped and had to be cut up, as all the fasteners and connectors were welded together. No-one was injured, though there were many fax machines and modems that were destroyed in houses. They are more likely to fail as they have a limited ability to withstand high voltage on the phone line ( lightning season brings a lot of replaced phone accessories that are mains powered) and have a direct connection to ground. The human on the phone generally is on a very good insulating surface, and most energy will be dissipated in arcing over on the line, with a limited amount getting to the phone instrument, which generally is quite well insulated from the user.