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Help in Understanding Relay

Guest urbanmiles

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Guest urbanmiles

i have this another setup where i connected a 12v 5a 3PDT Relay with a 12v 1A adapter,

am i right that from the given coil rating of the relay (12v) and a contact rating of 5Amax, the maximum wattage that it can handle would be 12v x 5a which is equal to 60W ?

what if i connected it with a 12v 1A adapter ? does this mean that the relay can now only handle 12v x 1a = 12Watts maximum contact rating ?
or it can still handle 60W regardless of the amperage of the adapter i use as long as it is 12V and not exceeding the maximum contact amperage which is 5a ?


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The coil ratings and the contacts ratings of a relay are completely different.

You show the 12V adapter powering the coil of the relay. The current is low but you do not say the coil's current.
The contacts of your relay are not connected to anything so they have no current.
Each contact can conduct 5A and there are three contacts so the maximum allowed contacts current is 15A. You do not say the voltage rating of the contacts so we cannot calculate the maximum power the relay can switch.

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Each contact can switch up to 5A so the total for all three contacts is 15A. We do not know the voltage the contacts will switch so we cannot calculate the power (voltage times current) that is switched to a load.

EDIT: You are very confusing because your relay contacts are not connected to anything. Your 12V adapter is connected ONLY to the relay coil which has a low current of 75mA DC, not 5A.

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