Australia EESS Q&A – UPS & PDU

Note: this Q&A contains personal opinions only, that are of a general nature. They have not been reviewed or endorsed by any organisation or regulatory agency, but are provided as a friendly informational perspective only. In all cases, readers should rely on their own research and professional & legal advice.

Q: Are UPS or PDU covered by L2/L3 categories in the EESS (for example as battery chargers)?

A1a: I’m going to assume the enquirer meant a 230 V ac input-output UPS was intended.  The short answer is: although a UPS does charge a battery, it appears to be L1 equipment only. This is because the regulatory definitions are in AS/NZS 4417.2, and B.2.36 there specifies that for the device to be covered by L3 for Australia or L2 for NZ, it has to have an output voltage not exceeding 50 V a.c. or 120 V d.c only, which is the ELV range. In case of doubt, the referenced battery charger standard is AS/NZS 60335.2.29, and the latest version of that says it only applies to equipment with ELV outputs, so that can’t be applied to an LV (230 V range) output device either.

A1b: If the UPS has a detachable power cord set, the mains plug, flexible cord and the appliance coupler all need individual certification at L3. It’s a good idea to use already-certified standard cord sets, so if you’re using already approved parts in the cord set for the UPS,  you don’t have to certify them again to use with the UPS. If the cord set is non-detachable, only the mains plug is an L3 part.

A2: PDU (I assume the enquirer meant power distribution unit) is a little trickier. The short answer is they’re generally L1, but it depends, so please read on: The closest regulatory category to that is B.2.34 “Outlet device” in AS/NZS 4417.2. 

A2a: A PDU consisting of appliance outlets such as IEC 60320 types in a strip would be exempt from L2/L3 as a whole, because the definition for outlet device covers socket-outlet devices (as per definition B.2.45) only. 

A2b: Further, if the PDU was built into a machine, such as a rack, it’s not portable, and that would exempt it from B.2.34 as well even if it used AS/NZS 3112 socket-outlets.

A2c: The socket-outlet (if used instead of AS/NZS 60320 (IEC 60320) appliance outlets) itself would be L3, because of definition B.2.45.

A2d: The supply flexible cord (B.2.47) would also be exempt from L2/L3 if it is directly connected to the equipment (non-detachable) – because of part (f) of the definition.

A2e: The power attachment mains plug also needs to be considered L3 per B.2.35. Again, it’s a good idea to use certified parts if the part used is within the definition.

Hope the above observations will be of use to somebody. Again, the answers depend on your own product circumstances, and there might be other arrangements I haven’t discussed above, so its important to seek your own professional advice.

PWR.

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