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I'm making a PCB board where I'd like a barrel connector rated for 10 amps. I have been using part this part which is rated for 10 amps at 50V.

https://www.digikey.com/en/products/detail/globtek-inc/JACK-C-PC-10A-RA-R/8597889?s=N4IgTCBcDaIFIEEDCBpAtEtAFTBGADAmgEoIAUxAlCALoC%2BQA

My PCB board however only runs at 5V. Can I safely use a barrel connector that's rated for, 6 amps rated for 48V, but at 5V and 10 amps? Or are parts rated for 6amps at any voltage?

I'd like to get my cost down and switching to a cheap plastic unshielded barrel connector saves me $2.75 per board.

https://www.digikey.com/en/products/detail/tensility-international-corp/54-00129/9685438

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    \$\begingroup\$ No, you cannot. Too high a voltage arcs and punches through things. Too high a current overheats and melt things. You can see how that is unrelated. \$\endgroup\$
    – DKNguyen
    May 28, 2022 at 23:00
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    \$\begingroup\$ ratings - they mean something! \$\endgroup\$
    – Marcus Müller
    May 28, 2022 at 23:05
  • \$\begingroup\$ Thanks for the confirmation, thats what my feeling was but wanted to make sure. \$\endgroup\$
    – user2508385
    May 28, 2022 at 23:11
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    \$\begingroup\$ No, and in fact I wouldn't use it right up at the manufacturer's rating. I've seen a lot of cheap connectors burn up. \$\endgroup\$
    – Spehro Pefhany
    May 28, 2022 at 23:52
  • \$\begingroup\$ The problem even ASUS makes is the surge current oxidizes/burns the plating so the surge current might exceed the rating and even when using less than rated, reliability might be only <5 yrs instead of 50 years. But if static installed and not inserted daily , ok Reliability drops 50% for every 10'C rise \$\endgroup\$
    – Tony Stewart EE75
    May 29, 2022 at 2:49

1 Answer 1

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No. Voltage has nothing to do with current rating.

Current ratings in connectors are usually (always?) based on temperature rise. For example, maybe the connector was tested at 5 Amps and it was found that after a long time, the temperature of the connector stabilized at 60 degrees in a 25 degree room, so this was declared to be the maximum allowable current. (I am just kind of making up numbers here to explain the idea.... these are not real numbers from a real connector).

However, if you know that your room will always be 10 degrees, maybe you can get away with running the connector at 6 Amps. Likewise, if you are only going to run 6 Amps for 5 minutes, then rest for 1 hour, maybe that is OK, too.

But doubling the current will probably cause the connector to overheat fairly quickly. So, the best thing to do is use the component within its published limits, or test it yourself to make sure it will work satisfactorily.

Connectors get hot because they have some resistance, R. The power dissipation in the connector is I2R. So doubling the current will quadruple the power dissipation and temperature rise in the connector (even more than quadruple because of the positive temperature coefficient of resistance).

So if a connector runs at 60 C in a 25 C room at 5 Amps (5 Amps -> 35 C temperature rise), then when you double the current to 10 Amps it will probably stabilize at over 165 C (10 Amps -> 140 C temperature rise). Unless the plastic melts first.

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