On Sun, 29 Jul 2018 14:00:55 +0100, Scott wrote:

On Sun, 29 Jul 2018 13:49:58 +0100, Tim Watts
wrote:

On 29/07/18 12:31, Scott wrote:
On Fri, 27 Jul 2018 09:10:25 +0100, Tim Watts
wrote:

Hi,

Who makes good domestic UPSes these days? Looking for about 500VA
(need to put a power meter in to be sure) and 30 mins runtime.

But it's more about which make and possibly series are any good?

Would like a decent output too (proper sinusoidal).

Sorry, a basic question. Do these devices detract from energy
efficiency? If leaving stuff on stand-by is frowned upon, is a UPS
not even worse?



Don't care

Well, I do. I'm not spending any of my time trying to set up an energy
efficient home only to have it undone by one appliance.

I was hoping for an answer to my question.

I can satisfy your curiosity about that for three APC models of UPS if
that's any help. The SmartUPS2000 draws 32 to 35 watts depending on the
actual mains voltage I suppose. The much smaller SmartUPS700 draws a
whopping 20 watts for its miserly 450W/700VA's worth of protection and
the tiny BackUPS500 takes a mere 2.7W for its 'quasi-sine wave'
350W/500VA's worth of protection (also, it only uses a *single* 7AH 12v
SLA).

These "maintainance" consumption figures exclude battery charging
activity (i.e. the figures are for when the battery packs are well and
truly charged up and drawing less than a milliamp of charging current).

The UPS manufacturers rarely, if ever, mention the "Maintainance"
consumption figure in their specifications. All UPSes consume some power
whilst in service ready to switch over to their battery powered inverter
supply in the event of a mains outage.

That tiny BackUPS500 was the only one that consumed what I'd hoped all
similarly rated UPSes in the sub 500W class would be specced for. A 3W or
less maintainance figure for a 350W/500VA unit is a not unreasonable
energy cost but discovering that the 450W/700VA rated SmartUPS700 was
taking 20W regardless of whether or not its fully charged battery pack
was connected was a rather shocking surprise.

Scaling that up threefold to the SmartUPS2000's level of 1500W/2000VA
protection would equate to a 60W maintainance figure which is what made
the SmartUPS2000's 32 to 35 watts figure look so economic by comparison.
However, despite the better maintainance consumption to protection ratio,
that's still a significant running expense added onto a household's
annual electricity bill.

At one time I had a total of five UPSes in service, adding some 80 watts
to my background consumption when each watt of 24/7 consumption
approximated to a pound a year's worth of electricity. I've now cut that
down to about 35 watts which now works out to about a quid's worth of
electricity a week which seems a reasonable premium to pay for protection
against any unplanned outages.

Of course, these are all 20 years or older models and one might hope for
lower standby consumption figures with more current models. However, I
wouldn't bank on that being true unless the manufacturer is prepared to
publish this figure of merit in the specifications.

--
Johnny B Good