[OZAPRS] hardware suggestions

vk2tv vk2tv at exemail.com.au
Thu Feb 18 13:28:10 AEDT 2016

Things staying the same makes it easier for old blokes like me, hi.

Likewise here with HV/LV transformers having manual tap changers, with 
usually 5 steps. We ran a nominally 11,000 volt system so the tap 
changer had taps at 10,500, 10750, 11,000, 11250 and 11,500, but our 
adjacent neighbour at the time (amalgamated since 1980) used a nominal 
supply of 10,500 so their transformers had that voltage as the centre 
(middle) setting. I can't remember how many steps the auto-tap changers 
in zone sub-stations had. I should because I calibrated them often 
enough, but the passage of time ....... rhubarb, rhubarb.

When I went out as SIO in 1974 the area where I worked still had a 
bucket load of 7/.080 copper mains in the air, and sometimes half a mile 
of it to the end consumers. Back then the first indication the consumer 
had about voltage issues was usually the TV picture shrinking during the 
evening peak. All of that 7/.080 is long gone and so have valve TVs, 
solving two problems.

Ray vk2tv

On 18/02/16 12:41, Matthew Cook wrote:
> Old habits die hard after 27 years in the Electrical industry I still 
> think of the nominal mains supply being 240VAC at 50Hz.
> I perhaps should have been more accurate with; my original statement 
>  "It's better your iGate sips and not sucks on the nominal mains 
> supply regardless these days o_O"
> Your nominal mains voltage (and frequency for that matter) will 
> certainly not be the same as mine for the very reasons Ray has pointed 
> out.  I'm sitting here watching the nominal mains voltage at our 
> industrial building hovering around 251.2VAC with a mains frequency of 
> 49.557987Hz (with better a accuracy better than 1e-9 Hz).  I'm sure 
> I'll see that climb back above 50Hz in the next 15 minutes as the 
> generators correct the loss over the remainder of the day. There's 
> certainly been a power demand spike somewhere in the VK5 network today.
> I agree with Ray that nothing really changed when the nominal mains 
> voltage limits in AS60038 were updated, the limits were effectively 
> still the same, well within a few volts of the same write that off to 
> minor percentage differences.
> Most of VK5 is still largely manual tapped transformers between the 
> HV/LV networks.   As a result our mains voltage can vary like a drunk 
> skunk due to network load.  Only made worse by the high prevalence of 
> solar inverters and wind generation now invested within the electrical 
> network.  Our energy market can see large cloud masses drifting across 
> our state before our Bureau of Meteorology.
> Now getting back to the APRS hardware Liz asked us all about.
> 73
> Matthew
> On 18 February 2016 at 07:31, vk2tv <vk2tv at exemail.com.au 
> <mailto:vk2tv at exemail.com.au>> wrote:
>     Matthew, all,
>     AS60038, was published in Australia on 23rd January 2000 toreplace
>     the previous 240V standard. This requires, under normal service
>     conditions, that thevoltage at the point of supply should not
>     differ from the nominal voltage of 230/400V by more than +10%,-6%.
>     Voltage drop within a customer's premises may reduce this by
>     another 5%, the maximum permissible under AS/NZS 3000, known as
>     the Wiring Rules.
>     Essential Energy therefore say that the total variation can be as
>     wide as +10%, -11%. Essential Energy realises that this voltage
>     range may cause issues with 240V equipment and they, therefore,
>     have adopted the range of 230V, +10%, -2%, which aligns very
>     closely with the old 240V standard. When I was the Supply
>     Irregularity Officer with a County Council (not Essential Energy)
>     the standard was 240V, ±6%, or 226V-254V. I know that other states
>     had different standards at the time, and maybe they still do.
>     The current Essential Energy "standard" of 230V, +10%, -2%, is
>     within AS60038 requirements, and returns a voltage range of
>     253V-225V. The AS60038 percentages return 253V-216V.
>     During my time in the position of SIO the nominal HV supply was
>     11,000V, and that tap setting was chosen on distribution
>     transformers. Under unloaded network conditions the LV would be at
>     near the top allowable figure of 254V, and network load would
>     reduce that figure.
>     Whilst the "nominal" voltage may be 230V according to AS60038, in
>     practice, it appears little (nothing?) has changed since the 240V
>     standard.
>     Ray vk2tv
>     On 17/02/16 21:30, Malcolm Larkin wrote:
>     We haven't had 240V AC in Australia since the 23rd of January 2000. The day we dropped to 230V
>     It is allowed to be +5% / -10% (241.5 to 207) Previously when 240,
>     it was ± 10% so 264 to 216
>>     Sent from my iPhone
>>>     On 17 Feb 2016, at 18:56, Liz VK2XSE<edodd55 at gmail.com> <mailto:edodd55 at gmail.com>  wrote:
>>>     QTR Wed, 17 Feb 2016 09:41:42 +1030 Matthew Cook QTC
>>>>     It's better your iGate sips and not sucks on the 240VAC regardless
>>>>     these days o_O
>>>>     73
>>>>     Matthew
>>>>     VK5ZM
>>>     Mine is solar powered - radio and the computer setup
>>>     The planned one is for a place where the power is provided by my son's
>>>     employer at very good rates ;)
>>>     -+-+-+-+-+-+-+-+-+-+-+
>>>     Liz
>>>     VK2XSE
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