Dry Contact?
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Dry Contact?
I believe the term "Dry Contact" is used more commonly in the alarm industry. Can anyone here explain or point me to a site that contains a good basic explanation of what a "Dry Contact" is and how it is used?
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dry contact
Dry contact refers to a contact of a relay which does not make or break a current. Usually some other relay or device has the job of starting or stopping the current. For example, a reed relay matrix switch is normally switched with all contacts dry. After the contacts are all connected, a wire spring relay connects a supervisory scan point, through which the current flows.
#3
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"Dry contacts" are relay switch contacts that are electrically isolated from the power that energizes the relay coil. Three classes: Form A (Normally Open); Form B (Normally Closed) and Form C (single pole-double throw).
It's mostly a north-american terminology; I think they call it something like "volt-free" or "zero-volt" contacts in Europe.
Here's a pretty good "white paper" on relays:
http://www.panasonic-electric-works....nformation.pdf
It's mostly a north-american terminology; I think they call it something like "volt-free" or "zero-volt" contacts in Europe.
Here's a pretty good "white paper" on relays:
http://www.panasonic-electric-works....nformation.pdf