Over-Voltage issues resulting from Solar-To-The-grid supply
Two breeders whose machines had behaved faultlessly for extended periods of time have reported an issue to me
Their issue was narrowed down to solar-to-the-grid supply
In the off-season, one breeder had installed a new solar array.
The second breeder's neighbour had installed a solar array.
In each case the issue was shared by other equipment so the energy supplier was called in to verify the delivered voltage
At its peak on a sunny day midweek the voltage exceeded the upper limit of the energy supplier's target margin
The supplied voltage target is 230VAC - (Less) 10% / + (Plus) 6%
If an over voltage condition is identfied, the energy supplier is obliged to rectify it.
This can be by switching the premises to a different phase or it can be by adjusting the closest transformer
Like most sensitive equipment incubators are susceptible to damage by over voltage
Over voltage can cause component failure and will shorten service life
From a Bulletin by the president of The Electric Energy Society of Australiahttp://www.eesa.asn.auThe 240V to 230V Switch
In Australia we have officially been a 230V country since 2000. However, no significant changes have been made
to the actual voltages delivered to most customers since the 240V days going back as long as I can remember. The
change to 230V in Australia has been more about convenient labelling than one of actually changing the way we
deliver power to electricity customers.
A recent article by Chris Halliday (Electrical Consulting & Training) and Dave Urquhart (Energex) has highlighted
the misalignment of various Australian standards and government regulations in the 230V/240V area. There is a
strong case for changing from the old 240V supply system to a true 230V system by actually lowering the steady
state voltage we deliver to customers. The new drivers for change are four fold:
1. Many customers are under the misapprehension that they actually receive electricity supply at 230V. The reality is that much of the
time the voltage is much higher near the top end of the old 240V ±6% range (253V).
2. The recent surge in connections of rooftop photovoltaics is causing new voltage rise pressures on the electricity networks and customer
installations that they were never designed for. This results in severe overvoltage conditions in localised areas that are causing voltage
stress on customer equipment and PV generation shutdowns caused by overvoltage inverter protection.
3. Many Australian equipment standards are written on the basis of supply voltage being near the nominal 230V level. e.g. motors have
an "A" range of 230V ±5%. There is a clear mismatch between equipment standards and the supply voltages actually being received
by most Australian electricity customers.
4. Specifications of mandatory Minimum Energy Performance Standards (MEPS) for customer equipment commonly call up performance
tests to be conducted at or near 230V. This is a voltage much lower than the environment in which most of these appliances need to operate.