Ask Dan: Why do Australian UPSes have IEC sockets on them?

Date: 15 May 2007
Last modified 03-Dec-2011.


I am an United Statesian who plans to move to Australia next year.

I plan on building a nice gaming rig once I move, and I would like to protect my equipment with a UPS.

All the Australian UPSes I've seen online have IEC outlets on the back. Obviously, you can't directly connect a piece of equipment to these outlets. Is there a power strip or something that one can buy to make these outlets useful? Or would one have to get adapter cables for each of these outlets?

Why are these UPSes designed this way? Is the standard Australian power plug too large to fit neatly on the back of a UPS?


This problem has annoyed geeks in Australia (and, I assume, several other countries) for many years, but it's easier to deal with now than it used to be.

Typical IEC-socketed UPS back panel

I think the reason for the ubiquity of IEC sockets on the back of Australian UPSes is just that it's easy to make a "world compatible" UPS that way. IEC sockets are usable, after a fashion, everywhere. Country-specific sockets aren't.

Australia, like a number of other countries with their own flavour of mains connector, is not a very big market. This whole country has about the population of New York State. That's not enough people, for a relatively niche product like a UPS, to justify making a whole special model just for us.

(Argentina has twice Australia's population and uses a similar plug to us, but with active and neutral reversed. And China, with 63 times our population, now uses a plug that's almost exactly the same as ours. But the other way up. It's almost as if they're toying with us.)

I'm thinking that this is why Australia, like other countries with oddball connectors, gets IEC-socket versions of all of the standard medium-sized rectangular UPSes.

If you only want a baby UPS, the kind that looks like a bloated powerboard, you can get one with Australian sockets on it; they're sold all over the place. They tend to contain odd skinny batteries that you can't buy cheaply, though, and those little batteries of course can't support a very powerful inverter, or give you a lot of run time. But they're available, and they work, and you don't need to lift with your legs to move them around.

The most powerful powerboard-shaped UPS I know of in Australia is the suspiciously cheap "PrOffice" unit from Upsonic (PDF datasheet here). It's a lot chunkier than most of its competition, and sports an alleged 650VA power rating, which the manufacturers guesstimate equals 390 watts (read about the difference between volt-amps and watts here). 390W is enough to run a boring business box and LCD monitor, no sweat, but a beefy gaming PC will push it harder, and give you maybe five minutes of run time.

Still, I think it's fat enough that the 7Ah battery in it is the standard brick type that you can buy from any electronics store (which you can replace with something humungous for more run time if you're a hackin' fool), and Aus PC Market sell the thing for a mere $AU140.80 including Sydney metropolitan delivery here in Australia (delivery elsewhere costs more; Australian shoppers can click here to order one). So you can't really complain.

The only larger UPSes I've found that you can plug an Australian mains cable straight into have "universal sockets" on the back, which look like this:

Worryingly universal mains sockets

These sockets are the same ones you'll find on dodgy off-brand travel plug adapters, and I believe they're likely to signify a similar level of compliance with legally mandated electrical codes (here's a fantastic example of the breed). The only UPS I own that has them is one that I bought super cheap on eBay.

I would not trust that UPS with the life of a goldfish, even if I did not very much like that goldfish.

IEC sockets, in contrast, have a shrouded-pin design that makes them safer than many standard mains connectors. A partially unplugged IEC connector, male or female, doesn't have any exposed live metal. Modern Australian mains plugs are required to have partially insulated pins for this same reason; recent Australian extension cords have sprouted shrouds around their socket ends, too, which have to be chopped off if you want to plug in an old flat-fronted plugpack.

IEC sockets also do take up less panel space than just about any other earthed mains socket in existence.

But I don't think safety or space efficiency has much to do with the issue. I think it's just more profitable for UPS companies to make one IEC-connectored version of each of their larger models for all of the smaller markets.

Remember that the UPS companies are already forced into involuntary market segmentation by the 115VAC/230VAC divide and the 50/60Hz one. It's a heavily segmented world for manufacturers of anything with an inverter in it, even if you ignore plugs and sockets entirely.

So that's why we've got them. What to do about it?

IEC-socket UPSes are, as you might imagine, something of a pain to work with.

Standard computer power leads with a regular mains plug on one end and an IEC female on the other are easy to find, and so are IEC male-to-female leads, which are used to hook up the switched IEC socket on the back of many computer PSUs to a monitor.

IEC male-to-females are only useful for running things that have an IEC input of their own, though. That counts out a lot of the stuff that people want to plug into a UPS.

So what you need to use an IEC-connectored UPS with ordinary equipment is an adapter with an IEC male plug on one end and a standard mains socket on the other.

And, fortunately, you can buy such a thing.

The Australian electronics chain Jaycar sell such adapters, catalogue number PS-4100, for a rather exorbitant $AU8.95. That's about what you'll pay for one on the Australian eBay site as well, possibly because the eBay dealers are buying the things from Jaycar's wholesale arm.

M'verygoodfriends at Aus PC Market sell the same thing for $AU17.60. Which includes delivery to anywhere in Australia, but is still a pretty hilarious price for a chunk of wire. Fortunately, they also have a four-pack for only $AU48.40 delivered. That's six bucks more than Jaycar will charge you for the same number of cables mailed to your door, but Aus PC Market's delivery is an Australian Air Express courier that'll get the stuff to you faster.

So that's the sensible way to solve the problem.

And now, the do-you-feel-lucky way!

Before the adapter leads existed, I dealt with the IEC-socket problem by getting a few IEC male-to-female leads (if you're at all friendly with an office IT person you'll probably be able to scare some up for free, on account of their uselessness...), and a few cheap powerboards, and grafting the plugs from the former onto the boards of the latter.

Bingo; lots of standard outlets from IEC sockets.

NOTE: Making these things yourself, if you are not a licensed electrician, is probably a violation of some law. As with other such creations, though, you are unlikely to suffer legal repercussions if your handiwork does not injure anyone, and you do not attempt to sell it.

If you screw up and burn your house down and your insurance company rejects your claim, though: Tough.

Realistically, anybody who knows which end of the soldering iron is hot and owns a variety pack of heat-shrink tubing should be able to make cables like this without endangering themselves or others. Just make sure you get the wires right. The modern Australian colour code is brown for live, blue for neutral, and green and yellow striped for earth. Check, check again, check with a multimeter when you've finished.

If you're hacking up an old powerboard or extension cord (which may or may not be a good idea - that cloth-insulated cable Grandpa used to listen to the wireless in the garden is probably not worth saving...), earth will be either green and yellow or solid green, but live will be red and neutral will be black.

Plugging powerboards into UPSes makes it quite easy to exceed the UPS's rating. If you've got a cable-jungle situation, label each powerboard and its plug so you can see which outputs come from the UPS and should be used for PCs and monitors, and which ones come from the wall and should be used for laser printers, refrigerators and toasters. It's perfectly OK to hang lots of low-powered things like clock-radios, plugpacks and compact fluorescent lamps off a medium-powered UPS, but you'll feel like a right Charlie if the power drops out, everything's fine, then your laser printer decides to reheat its fuser roller and overloads the UPS into which you mistakenly plugged it.

Also, if you're going to plug a powerboard into any UPS by any means, home-made or shop-bought, make that powerboard a plain vanilla model with no "surge protection" features.

It's OK if the powerboard has an overload protection circuit breaker (generally indicated by a little button sticking out somewhere to reset the breaker), but an actual surge protector may treat the non-sine-wave output of many UPSes as something in need of filtering, and waste power by doing so.

In reality, this too is unlikely to be a big problem. That's mainly because most of the world's surge protectors didn't do much power filtering when they were brand new and don't do any at all now that they're more than a year old.

But if you've got a big expensive surge-stopping powerboard, don't plug it into a UPS unless that UPS is a proper sine-wave unit. More and more UPSes have near-sine-wave output these days, but it's still not the way to bet. You don't need an oscilloscope to find out, though; just plug a desk fan into your UPS, turn the UPS and the fan on, and turn off the wall power. If the fan starts buzzing when it's running from inverter power, then that inverter power is not very sine-wave-y.

(Proper ultra-heavyweight ferroresonant power conditioners, also mentioned in this column, should work fine from UPS output. If you're wondering whether your surge buster is a proper power conditioner, though, I'm afraid that means it isn't.)

While I'm scolding you all about bad things that you probably haven't even considered doing with your UPS: Do not daisy-chain UPSes, or plug them into themselves.

Usually, people plug UPSes into themselves by accident, but I'm sure plenty of bored nerds have made a UPS circle deliberately, just to see what'll happen. One UPS plugged into itself will go clickety-clickety-clickety until it fails, which probably won't take long; make a ring of them and they'll click in a more haphazard way and survive longer.

For maximum entertainment, plug a lamp into each UPS in the ring so you can see when it's on, and enjoy your inverter-powered disco for as long as it lasts.

Oh, and plug in a shredder, too.

For the warranties.

Australian shoppers can purchase a selection of fine UPSes from Aus PC Market.
Click here to order!