No risk of electric shock at these voltages. But in salt water environments, a greatly increased risk of corrosion. Which could in turn lead to a shock or fire hazard.
Slightly off topic, but a valid point to be considered. Peter Merguerian wrote: > Jason, > > Please explain to your colleague that for North American requirements (as > depicted in the NEC and CEC) there is no risk of electric shock or fire from > circuits in wet locations for up to 21.2 V. For higher voltages you should > start taking steps to minimize the risk of water ingress and the risk of a > person coming in touch with the circuits. > > In Europe, I believe the voltage level is somehat lower; if I recall > correctly, 15 V. Someone correct me if I am wrong! > > This e-mail message may contain privileged or confidential information. If > you are not the intended recipient, you may not disclose, use, disseminate, > distribute, copy or rely upon this message or attachment in any way. If you > received this e-mail message in error, please return by forwarding the > message and its attachments to the sender. > > PETER S. MERGUERIAN > Technical Director > I.T.L. (Product Testing) Ltd. > 26 Hacharoshet St., POB 211 > Or Yehuda 60251, Israel > Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 > Mobile: + 972-(0)54-838175 > > -----Original Message----- > From: jasonxmall...@netscape.net [mailto:jasonxmall...@netscape.net] > Sent: Thursday, January 03, 2002 12:57 AM > To: emc-p...@majordomo.ieee.org > Subject: Electric Shock and Water > > My apologies if this is just too naive... > > I am trying to explain to a collegue why there are so many cautions against > "mixing" water with electricity. He is not the type to accept "common sense" > as an answer. This is what I have reasoned so far... > > MAL-OPERATION > Water is generally conductive. If it enters the area of a chassis that > houses control elements such as relays or switches, it can short circuit the > control elements and cause the affected device to "operate" unexpectedly, > and sometimes in unexpected ways. > > ENERGIZING SURFACES > Water is generally conductive. If it enters a chassis containing hazardous > voltages it is possible it may act as a conductor of the voltage to an > otherwise un-energized conductive surface. If the conductive surface, for > whatever reason, is itself not sufficiently grounded, it can carry hazardous > voltage potentials. > > INCREASED LEAKAGE CURRENTS > Water is generally conductive. If you are working on a chassis and > accidentally touch an energized contact, you may not experience any shock > because there is no current path between you and the voltage source > supplying the contact. Let us assume the contact is energized by a local AC > mains. There is always SOME leakage current possible from where you are > standing back to a grounded point. Usually it is a very small leakage. > However, if you are standing in water, the leakage current is likely to be > much higher, and you may experience a serious electric shock from your > accidental touching of a contact. > > AVALANCHE EFFECT > Water is generally conductive. If it enters a chassis with high power > electrical components, it can instigate an avalanche of failure that results > in the release of a lot of energy. For example, the water can provide a > short circuit between two potentials. As it carries current, the water may > heat up quite rapidly, in doing so it creates steam. The effects of the heat > and steam may then provide an even lower resistance path for additional > current flow...and so an avalanche of conductivity (from less conductive to > more conductive) is started... > > I welcome any comments and additional "generic" scenarios. > > Regards, > > Jason Mallory > Product Safety Consultant. > > -- > > __________________________________________________________________ > Your favorite stores, helpful shopping tools and great gift ideas. > Experience the convenience of buying online with Shop@Netscape! > http://shopnow.netscape.com/ > > Get your own FREE, personal Netscape Mail account today at > http://webmail.netscape.com/ > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. -- Andrew Carson - Product Safety Engineer, Xyratex, UK Phone: +44 (0)23 9249 6855 Fax: +44 (0)23 9249 6014 ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
