Another interpretation of the terms "dry circuits" and "dry contacts" is application related. "Dry circuits" are not "wetted" with a voltage, as analog POTs lines are. A set of contacts in a "dry circuit" might be used to detect an open-circuit -vs- a closed circuit condition, without appreciable current flow in the closed-circuit condition.
"Dry contacts," might open or close on a circuit with no appreciable voltage, for instance a set on contacts controlling the grounded side of a circuit or for a ground detection circuit. The terms including "dry" do not contain any notion of the switching capability of a set of contacts. Regards, Peter L. Tarver, PE [email protected] > From: Chris Maxwell > Sent: Monday, February 23, 2004 10:49 AM > > David, > > Dry contact relays are named because of what they > don't have. Many high > current relay designs feature contacts that are > wetted with Mercury in > order to prevent damage from arcing during > make/break cycles. > From: [email protected] [mailto:[email protected]] On Behalf Of Cereceres, David Sent: Monday, February 23, 2004 1:26 PM To: '[email protected]' Subject: dry circuit questions "When you see a reference to either 'dry contact' or 'dry circuit' as far a relay goes, what does this mean the relay is designed to handle?" As always, your guidance is always appreciated. Regards, David Cereceres This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
