[plug] Shameless plug <sigh> 60KVA UPS

[Mike from West Australia]

At 12:13 PM 1/5/2000 +0800, you wrote:

>> In the event mains has failed, batteries are supplying load, efficiency at
>> that
>> point is 92% at full load. ie to Supply 60KVA, then battery consumption is
>> 60,000/0.92 = 65217 Watts. Rather less then your 700KW figure !
>
>What, only 92%? What happened to the other 8%? Is this some GST thing?

No, unfortunately...

Normal consequence of losses in switching devices, capacitors, inductors
etc etc Even a piece of wire is not 100% efficient. At lower loads
the efficiency is closer to 99% -> 98.5 I think :)

>You notably did not state any specs for the backup draw and duration (5
>minutes? 10 minutes? 24 hours?)

Depends totally on the load power factor - worst case is 15mins at max
load. At 20KVA its around an hour - you get more time the less load,
not just to porportionality but also due to higher efficiencies (less
switching losses) at lower loads. At 20KVA its around an hour...

And yes Linux drivers can be had as required.


Rgds


Mike Massen

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