If there is only a very remote chance of the product being connected to *public* LV mains supplies (as opposed to industrial supplies from a dedicated MV/LV transformer), 61000-3-2 doesn't apply. Does it meet the Class A limits?  I agree that it's 'professional equipment', but, as you see, the standard is not totally clear in this context. I will follow up with the IEC committee. It may take a few days to get an answer.

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associates www.woodjohn.uk
Rayleigh, Essex UK

On 2017-10-11 17:08, James Pawson (U3C) wrote:

Hello John,

It uses phase angle control hence the concern about the harmonics generated.

Manufacturer specs are single phase, 230V nominal, 3kW.

Typically used at less than a 15% duty cycle, often less, in an industrial environment or powered from a generator.

My *feeling* is that should be classified as professional equipment and exempted under Clause 7 but the IEV has 0 search for feelings.

Thanks for your help

James

*From:*John Woodgate [mailto:j...@woodjohn.uk]
*Sent:* 11 October 2017 16:49
*To:* EMC-PSTC@LISTSERV.IEEE.ORG
*Subject:* Re: [PSES] IEC 61000-3-2 Confusion

I agree that there appears to be a need for clarification, and I will take that up with the committee responsible. But for your particular case, what is critical is the nature of the 'triac control'. Is it phase-angle control, or 'burst firing' or something else?

John Woodgate OOO-Own Opinions Only
J M Woodgate and Associateswww.woodjohn.uk <http://www.woodjohn.uk>
Rayleigh, Essex UK

On 2017-10-11 15:01, James Pawson (U3C) wrote:

    Hi folks,

    I apologise as I seem to be all take and not much give on this
    forum at the moment; I’m trying to do a lot of learning very
    quickly. Someone ask a question about HDMI so that I can feel useful!

    Today’s question is what appears to be a contradiction in IEC
    61000-3-2:2014.

      * The customers equipment is a triac controlled high-power PSU
        for welding plastic parts together using resistance heater coils
      * Power is over 1kW and the customer is suggesting that it is
        “professional equipment” which, according to Clause 7, means
        that harmonic “limits are not specified in this standard”
      * Flowchart in Clause 7 says that Clause 6.1 for allowed control
        methods still applies even to equipment with no limits
      * Clause 6.1 says symmetrical control methods which produce
        large low order harmonics (arguably this applies to triac
        control) that are used to power heating elements (applicable)
        provided that either input power is less than 200W (it isn’t)
        or the harmonic limits of Table 3 apply
      * Clause 6.1 also says that symmetrical control for professional
        equipment is OK provided one of the “above conditions” is
        fulfilled (which it is, see previous bullet)

    So we’ve gone from Clause 7 saying no limits apply to Clause 6
    saying that Class D equipment limits apply.

    However the flowchart in Clause 7 suggests that just by being
    exempt from Clause 7 limits means it automatically conforms to
    61000-3-2

    I feel like I’m going in circles. Does anyone have any insight
    that might help?

    Much appreciated,

    James

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