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I need to use panel mount power entry C14 IEC inlet to turn on/off an SMPS inside an enclosure. The SMPS however has 70A inrush current and my IEC inlet's switch's inrush current were not mentioned(only 6A nominal current was mentioned). When I contacted the manufacturer they replied me that the rocker switch of the inlet is 45A. This is much lower than the my SMPS's inrush current(70A).

My two questions are:

  1. Am I correct that the rocker switch inrush current is too small for the SMPS? Is there a regulation for CE marking or standard for this?

  2. I have hard time from a restricted vendor(I can only purchase from this vendor) to find an IEC inlet with high inrush current mentioned. I came up with this inlet available but its rocker switch is not high inrush type. I then found this rocker switch from the same manufacturer. Can I just replace the IEC inlet's rocker switch with the high inrush version in this case?

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  • \$\begingroup\$ Can you use an inrush current limiter of some type? \$\endgroup\$
    – Hearth
    Commented Oct 1, 2022 at 21:09
  • \$\begingroup\$ 70A in rush current seems excessive to me, like the product was perhaps under-designed. A simple fix would be an "in-rush current limiter" (ICL), a type of NTC thermistor, wired in series with the mains "hot" connection. Example: digikey.com/en/products/detail/cantherm/MF73T-1-10-10/9919659 To choose a exact part, we need to know few more things, like what the normal steady-state current flow is. \$\endgroup\$
    – Rich S
    Commented Oct 1, 2022 at 21:10
  • \$\begingroup\$ @RichS In my case the AC side nominal current will be less than 0.5A. But I asked long ago a question here how to size it no one had an answer: electronics.stackexchange.com/questions/634446/… \$\endgroup\$
    – user1245
    Commented Oct 2, 2022 at 16:00

2 Answers 2

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The switch is to be selected from 'high-inrush current' models, considering the TV rating mentioned in their data sheet.

The TV rating, as per UL and CSA standards, is an assessment of the inrush current withstanding capability of switch or relay contacts as follows:

TV3 - 51A, TV4 - 65A, TV5 - 78A and TV8 - 117A, TV10 - 141A, TV15 - 191A.

TV5 and TV8 rated switches, intended for use as 'Power On' devices, are available.

You would need to separately mount the TV5 / TV8 rated switch and the mains input socket.

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Many different loads have high inrush currents .Examples: Incandescent lamps ,Motors, Transformers. This was long before Cheap SMPS became popular. Sure better often more expensive SMPS has inbuilt inrush current limiting. If you want to keep your existing SMPS then you can get switchgear that has a weld current spec .For example the cont inious rating could be say 10 Amps and the weld current could be say 100Amps .For your job such a switch would be good.

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