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[LUG]Re: OT: Voip power cut, FTTC

 
On Mon, 16 Dec 2024 20:35:25 +0000 (GMT)
Gordon Henderson <gordon+lug@xxxxxxxxxx> wrote:

> 100A gives you a serious amount of power to use - 23Kw. Given that a 
> standard outlet can only supply 13A/3Kw then where is the rest going?
> An induction hob (4+1) zone) can max. out at 4.5Kw. Fast heating
> oven, also 4.5Kw. What are you using the rest for? Given an 80A
> limit, then it's a mere 18.5Kw. More than enough to run your hob and
> oven full blast as well as washing machines, etc.
> 
Not quite sure about this, some of these figures seem a bit low.  Our
Mira shower runs at 9.5kW; accepting the figures above for (twin?) oven
at 4.5kW and the hobs at 4.5kW; add in a single 3kW electric heater.
Our home office runs four 1200W UPS supporting three towers, the two
modems plus hubs, VoIP, and the printer, say 500W; during the working
day, add four laptops, a few lights and a bit of heat, say another 500W;
with the fridge/freezer at about 250W that's about 1.25 kW of
background. Twin immersion heaters can add another 6kW for the 3 hours
it takes to heat the water from cold. 

That's where 'the rest' is going in our household of two working adults.
The issue is that at the end of the working day, the cooker, shower and
heating all get activated, so for a period of an hour or so, the draw
can be easily in the region of the 23A, even if background consumption
is in the 5-10A region for the rest of the time.

I lost my best machine a couple of years ago due to a power cut.  When
the power was restored, there simply wasn't enough power available to
go around (the whole industrial estate went down); after 'restoring
previous state' (bad idea), three of them rebooted to some kind of
zombie state, which I discovered next morning when I arrived; one since
rebooted ok, one was able to be rescued after a reformat and
repartitioning, but one lost a stick of memory and one of its CPUs and
only the dark arts and sorcery got it through the RAID controller. The
insurance eventually stumped up and paid for the 5 (one has since died)
UPSs above (1200 AV PowerWalkers, 14 Ah, £180 each).  Now, the main
machines are behind batteries of some sort, and those that are not,
stay down if they go down. 

I'll let the list know if I can keep the modems up for the full 11.5
hours if we get another power cut...  

Best of luck to you with all your solutions, it's been a helpful thread.

fraser

 
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