Any harmonic standards for switch-mode power supply have to pass in US 2

[drchen]

I am going to design switch-mode power supplies/battery chargers just for US market. I know if these products designed for CE market, they have to pass EN61000-3-2 harmonic standard, which means the designs must include PFC functions. But if the products just for US market, any similiar harmonic standard must pass? I know US recommends following IEEE-std-519, it is a voluntary standard not mandatory one, am I right? So in my design PFC function is not necessary for US market in order to reduce the cost. The next question is when the US harmonic standard(like IEEE-std-519) will become mandatory?

 

[dpc]

The intent of IEEE 519 is to establish guidelines for harmonic distortion at the interface between an electric utility and a utility customer. It really has nothing to do directly with something like a small power supply.

Your power supply will be subject to mandatory regulations established by the Federal Communications Commission(FCC)regarding radiated noise, and voluntary standards established by Underwriter's Laboratories(UL). The UL standards are essentially mandatory, since no one will sell your product without a UL label. There are probably other voluntary standards as well, depending on the size and application of the unit.



I'd suggest visiting FCC website and contacting UL directly for more detailed information.

 

[busbar]

If I correctly understand your query, the authoring agency/standards-making body does not necessarily have enforcement authority over a national-consensus standard.

IEEE 519 not only considers harmonic-producing equipment, but also covers systems in an “umbrella” aspect; recognizing that interaction between electrical components may produce undesirable {usually unacceptable loss} in other parts of an electrical system not immediately proximate to the subject device.

519 limits get adopted by reference into facility- and equipment-procurement contracts. By omitting them, you haven’t necessarily committed a felony, but should their limits be overlooked, funds for projects or assemblies may get significantly delayed or denied until compliance has been satisfactorily demonstrated. Having to accommodate them later in a project cycle—id est, after the design phase—can get very expensive.

 

[drchen]

Thank you for your advices, dpc and busbar. I know power supplies for US market must pass FCC standards for EMC regulations and UL safety(UL1950) standard and AC input transeint test. The only thing I don't know is any Harmonic standard(like IEC/EN61000-3-2 for CE market) in US must pass or not?

 

[busbar]

Aside: 519 specifically excludes radio-frequency matters.

 

[RonShap]

At this time, there is no harmonic limit standards placed on individual system comonents. IEEE 519 recommends a limit at the utility interface. There are many discussions within IEEE to add a standard for individual components such as a single switch-mode power supply (called 519-A at one time).

 

[drchen]

Thank you, RonShap, your statement is very helpful. According to the papers published by USCCEMC Harmonics Workshop in 3/22/00, USCCEMC intended to disagree with IEC/EN61000-3-2(Harmonic) and IEC61000-3-3(Inrush). The Committee contnds the IEC standards as:
1. Absence of quantitative rationale for broad application of emission limits.
2. Failure to consider and employ the full range of aviailble mitigation techniques in order to optimize cost/benefit outcomes.
3. Unstable technical content in the standards.
4. Conflicting requirements between standards.

So look like USCCEMC(IEEE) perfer system-level solutions more than component-level solutions. So maybe we can reasonalbly predict that no component-level harmonic standard comes out in a few years. Now Maybe the condition is changed. IEEE plans to release a harmonic standard for individual component? When it will come out? Could you give me more information about this standards(519-A)?

 

[Lewish]

My understanding is, if the power supply is going into a home computer or entertainment product, it has to meet the same standards in the US that it does for CE.

The current push is to make PFC a requirement for certain products by July of this year, and to add to that list in succeeding years. Right now, that list is for all products which draw 1500 watts or more. I have several customers who are scampling to be ready to meet that requirement.

 

[drchen]

Thank you, Lewish. You mean power supply for home computer or entertainment product has to meet EN61000-3-2 and EN61000-3-3 in US market? And US is going to require PFC function for power supply? My power supply will be less than 500 watts, is it affected by the new harmonic limit requirement? Could you tell me what is the name of the standard(list) and where I can find it?