Switch Contact Ratings

Discussion in 'General Electronics Chat' started by tracecom, Dec 30, 2014.

  1. tracecom

    Thread Starter AAC Fanatic!

    Apr 16, 2010
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    There are two switches: one has a contact rating of .5A @ 50VDC and the other is .3A @ 125VAC. I am aware that ratings of all sorts are somewhat "iffy," but what I am wondering is there a way to determine what current the contacts would handle at 5VDC.

    Thanks.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Usually they have a rating that gives and idea.
    http://en.wikipedia.org/wiki/NEMA_contact_ratings
    Also there is Dry Contact types where the contacts cannot switch the primary current, IOW only open or close when the load is not present.
    As a general rule, even if going with a lower DC voltage say, IMO, it is not always advisable to go any higher in current.
    Max.
     
  3. wmodavis

    Well-Known Member

    Oct 23, 2010
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    .5A
     
  4. tracecom

    Thread Starter AAC Fanatic!

    Apr 16, 2010
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    Is that your answer for both switches? Thanks.
     
  5. wmodavis

    Well-Known Member

    Oct 23, 2010
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    For the DC rated switch. Don't think you can extrapolate DC ratings from the minimum AC ratings you gave for the other one. Look at manuf specs.
     
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The fact of whether it is switching a resistive or inductive load factors in to a large degree also.
    Max.
     
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