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03-24-2008, 06:31 PM   #1
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will a switch rated for 25 amps DC work with 15 amps @120v? I am assuming it should.

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03-24-2008, 07:23 PM   #2
david_42

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What is the voltage rating? A 25 amp 12 volt DC switch would probably fry.
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03-24-2008, 07:58 PM   #3
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Actually it is the other way around....AC current ratings are higher then DC current rating for a given voltage. The reason being that it takes a much more robust contact to break DC under load this is why large DC contactors have arc chutes or bellows to help extinguish arcs.

Here is the contact rating off of a relay on my work bench for example

15A , 120VAC
15A, 30VDC

The question is if it is rated for 120VAC, if it isn't marked as such then it isn't.

03-25-2008, 07:49 PM   #4
Shockerengr
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Feb 2007
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the other bit that goes in is the dielectrics used in the switch....keep in mind that a 120 VAC has a peak voltage of around 170v

03-26-2008, 02:11 AM   #5
slnies

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Quote:
 Originally Posted by Shockerengr the other bit that goes in is the dielectrics used in the switch....keep in mind that a 120 VAC has a peak voltage of around 170v
the 120 volt rating is a nominal rating and takes into account the peak.
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03-26-2008, 11:42 AM   #6
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Quote:
 Originally Posted by slnies the 120 volt rating is a nominal rating and takes into account the peak.
Yeah ratings are RMS voltage....