Q&A: 230 V, 240 V, whatever…

I’m an avid Renew reader, member and past contributor. We had a recent experience that we thought wouldn’t be uncommon amongst your readers and thought it would make an interesting story.

We’ve been living off-grid for the past five years. During this time we’ve had issues with electrical appliances breaking down, and each time as soon as the technician discovers we’re off-grid they blame the system. It’s a real fight to get them to consider other options.

The most recent example was today which prompted this letter. We purchased a new electronic fridge, and had a problem with it as soon as it was plugged in. I won’t bore you with the details, except to say that before even looking at or hearing the problem the technician had decided the problem was caused by our power, his rationale being that electronic fridges needed a constant 240 V supply.

When he tested our system is was only providing 230 V. Of course, in the end he finally admitted there was a problem with the fridge and a replacement is being sent.
What would have been really helpful was a fact sheet, written by a qualified person, to give to the tech explaining why the power system is not the problem. – Judy Celmins

You really have to wonder how up-to-date some technicians are, given that Australia officially shifted to 230 volts over a decade ago. This is why current inverters have 230 volt outputs, not 240.

The Australian Standard AS 60038 states the nominal mains voltage as 230 V +10%, – 6%, giving a range of 216.2 to 253 V. The ESAA Customer Guide to Electricity Supply gives more details on page 27 and indeed is a useful document to read for anyone interested in electricity supply in Australia. It can be found at www.bit.ly/WYBb66. Other similarly useful documents are ENA’s Customer guide to Electricity Supply at www.bit.ly/XInUhr and the Electricity Networks Operation Standards 2011 at www.bit.ly/Trfoor.

Even so, most appliances have a wide input voltage range, often from 200 volts up to 265 or so, depending on the brand, model and the markets the model is sold into. Indeed, most modern electronic devices use ‘universal voltage’ power supplies that handle 85 to 265 volts, although the fridge motor will be designed for a narrower voltage range. But, the motor doesn’t seem to be the problem, the electronic controls do, so the technician blaming the power supply on a voltage basis shows considerable lack of knowledge.

Having said that, if you are having a lot of electronic device failures then you might want to have the output waveform of the inverter checked in case it is producing a non-sinusoidal waveform or is producing a lot of electrical noise on the waveform. Any technician with an oscilloscope can check the waveform for any oddities. There might also be another appliance that is producing electrical noise that is damaging other appliances.
Lance Turner

Read more Q&A in Renew 122.