Upgrade to a three phase domestic supply?

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I have moved to an old 5 bedroom house that I plan to renovate, including a complete rewire.
This is also an opportunity to change the domestic supply from 100A single phase to three phase, if I wish.
I am trying to find a website that has a list of typical currents drawn by, or VA rating (not Watts - I don't know the appliance power factors) of, different domestic appliances so that I can calculate if I would exceed the 100A limit of a single phase supply. Anyone know of such a website?
Aside from the danger of 415V in the house, would anyone care to comment on the risk/reward of a domestic three phase supply? (E.g. higher standing charge?). I do not intend to use any three phase equipment in the house.
Thanks for your help.
Steve
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Pandora wrote:

Are you having all electric space and water heating and cooking ? You might then exceed the 24kW that the supply will feed you. Otherwise I doubt you can come close to needing it. Many UK supplies are limited at 60 A.
Steve
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Steve wrote:

About the only reason to install a 3-phase supply in a largeish domestic house is if there were going to be 3 or more instant electric showers in use simultaneously.
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Ed Sirett - Property maintainer and registered gas fitter.
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Are you intending to build a workshop with heavy machinery ? Are you going for a fully electric heating, cooking, automation systems etc. etc. ?
If you come close to needing a three phase supply for an ordinary 5 bedroom house without any specific installations that would use it, then you'll also be coming close to bankruptcy with bills you'll receive on using that amount of power.
Using triple phase and neutral supplies is typically used for industrial or excessively heavy domestic installation, i.e. letting out separate apartments, heavy workshop machinery attached to the house etc. etc. So anyone using such a supply is normally making money out of it to justify the need.
A simple test to carry out, is to wonder around the house and total up the load of all the electrical equipment you have plugged in to the mains supply. i.e. heating, lighting, cooking, laundry, food storage etc. etc. and see how much power it would use if it was all running at the same time, even all the little clock radios and things, and I think you'll be amazed at how little it really does draw compared to the supply's capability.
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I vaguely remember the woodyard I worked at having to pay three figure numbers for the upgrade. Up to then he was running everything on a diesel genny.
The genny would be viable if you had a means of abstracting the heat. (Think how much oil a CH boiler uses to no other effect but heating, while a generator not only burns the same fuel but supplies the lecky too, also, as well.)
A good ex-military genny would be cheaper than a tranformer on a stick in your garden. And you could use it to annoy the neighbours if they upset you -or even if they haven't (yet.)
OT:
How much oil does a central heater use? And what generators have a comparable fuel consumption? And how much would heat exchangers for the cooling and exhaust cost?
Got a link to that in the Corris site anyone?
Anyone know if you can use old lubricating oil in a diesel? I know that you can use it to spray a jet from an oil-pump onto a firebrick alongside a fan that would work as a blowlamp for melting aluminium scrap etc.
(Yes I know this is getting silly but I didn't start the thread.)
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The internal combusition engine's biggest product is heat. Far more heat than power is produced. Extracting "all" the heat, and it produces a hell of a lot, and power (electiucty) it is very efficient. But most people would not use all the heat and power available, so they are very inefficient.

Heat exchangers are not cheap. Many people make their own. It is using all the heat available. Having a small LPG genny, about 1.5 kW/hr, and extracting all the heat is feabile. But you have to extract all of its heat and store it in a large thermal store. Then your house has to be run mainly on LV lights, run from batteries overnight with the genny off, and all appliances run on gas (gas fridges are available). Washing machines, etc, have to be super energy efficient and hot and cold fill, with the hot water comming from the stored water. No appliance should draw more than 1.5 kW.
Now there are Combined Heat and Power Stirling units available. http://www.whispergen.com http://www.microgen.com/products1.html
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Excellent sites well the first one was excellent except that it gave no clear idea of the size weight and price. Ditto the other one but I couldn't get on with the way the pictures loaded.
I'd never heard of the stirling engine and am having difficulty with the concept. They seem to be shooting themselves with the overbuild quality as a fuel efficient small unit that wears out rapidly would sell if it was cheap enough to supply a site. It could be without the heat saving ad ons.
Of course the firms shown were designing a unit for specific purposes not including what I would buy one for. If I was in the market for a genny.
I wonder why they can't incorporate an oil way in the crancks and etc the way that motorcycle 2 strokes do.
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using
heat
mainly
etc,
water
kW.
Whispergen is available, so see a dealer.

The Microgen is available next Spring.

http://www.stirlinginfo.com /
Stirling's do not wear out rapidly. They are super simple with minimum components. The Microgen unit doesn't have a crank, with the piston being the only moving part.

Why? It works on a different concept and operation to an IC engine. Get al the stuff out your head about IC engines.
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time,
at
It's Sunday evening. Mum's doing the washing/drying/ironing, Dad's cooking lunch and four teenage children are showering/doing homework/watching TV. (Putting aside the debate about stereotypical representations) I think that this family could draw the following loads simultaneously:
12.5A (Washing machine) 14.5A (Tumble dryer) 6A (Iron) 1.5A (Fridge) 3A (Freezer) 12A (Dishwasher) 10A (Cooker (electric)) 6A (Microwave oven) 8A (Electric kettle) 2A (Hi-Fi Stereo, surround sound system.) 2A (2 x Computer) 1A (2 x 17" monitor) 6A (Hair dryer) 0.5A (TV) 1A (Computer) 0.5A (17" monitor) 2A (Shower pump) 2A (Extractor fan) 12.5A (Immersion or water heater) 3.5A (Central heating pump) 3A (Fan Heater 1/3hp) 10A (Lighting) 5A (Sundry electrical loads)
That's a total 124.5 amps. OK, we can argue that their approach to energy efficiency could be improved. In terms of rating a supply, however, a single phase 100A supply seems inadequate.
How do my load estimations look?
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High ;-) All the "small" things like fridges, freezers, ch pumps, fans, don't draw anything like the current you suggest, for a start. And 2300W of lighting ?
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wrote:

of
Plus ignoring pulling 14.5A from a 13A plug on the drier... ;)
D
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Hell, I have 540W of lighting in the kitchen alone :-}
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But is it Low Voltage Dichroic Lighting or Incandescent Lamps or GLS or Flourescent or Halogen or ? ? ?
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Bog standard incandescent - 3 * 3 * 60W reflectors - the room is about 18 foot by 7 foot, switched in a bank of 3, and a bank of 6 - if you knock the bank of 6 on first of a night it can take several seconds before your eyes recover, and it sure as hell wakes you up :-p
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I bet ya' it would wake you up. :-)) Is the room used as a craft workshop ? With that amount of illumination, I bet you can see the tinniest details.
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No, it`s just a standard domestic kitchen - although if my wife was replying to this, she`d comment about needing it that bright to see through the plumes of smoke when I cook :-}
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workshop ?

details.
LOL
Ah well ! If it's acting as emergency lighting, then it is better to have it as bright as possible. :-))
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Only for the small proportion of time it's heating water; "modern" machines use little water compared to older ones. And few have elements above 2kW. So a better figure for the peak draw would be 9A; and with some 15% of the time spent heating, rather than spinning, tumbling, etc., the average figure will be more like 3A.

Not as high as that, but could be 12A, and unlike the washing machine will be sustained for a longer time - 60-90 minutes.

Yes, but again there's a thermostat. If Mum's ironing her linen tablecloth with the steam going full on, you might see an 80% duty cycle; if she's just passing it over her Janet Regier with the iron set a bit under the one-dot position, it'll be a 5-10% duty cycle...

Unlikely to be that high for either, and again will be smoothed by thermostat action.

Same comment as washing machine: heating and drying account for say 50% of the duty cycle, the rest is spent spraying the already-hot water round the washdosh and rinsing its contents with cold water; so average down to 5-6A.

Yes, maybe that high if we've got all 4 plates on the go and something in the oven (each plate 2kW and maybe 1kW oven, but thermostats clicking in and about bring the average down near the figure you suggest).

Ooh, that's a big one, as the bishop said to... but seriously, most MWs are in the 600W-800W range, so 3A rather than the 1.5kW which 6A would mean. And is Dad cooking for real (on the cooker), or just heating something up (microwave)? Shirley he's not using both?

Yes, while it's on; but not for more than 4-5 minutes in an hour.

Hang on. If Dad's cooking, Mum's ironing, and the kids are doing homework on the three computers you've enumerated *and* watching teli *and* got the Hi-Fi on the go, who's left to wash the hair?

Hmm, it's the cat in the shower?

What, immersion *and* CH on the go at once? And there's a 'stat on the immersion; and that's a monster CH pump - steady-run current will be well under 1A.

Possible but profligate!

They're notably pessimistic; but they do show why (a) new builds usually have a 100A mainfuse these days, rather than the 60A which used to be standard; (b) illustrate why the main incomer is a cartridge fuse rather than an MCB (well, there's cost reasons too, and the vulnerability of an MCB to kids turning them off if they're in an outdoor-accessible meter cupboard). (The wired fuse allows getting on for twice the nominal rating to be drawn for a good few minutes before it blows, though it'll rupture within milliseconds with a serious short circuit.) In particular, lots of the loads you mention are thermostatically controlled, and you list the peak rather than the average. The heating effects in the circuit cables (from meter tails down to final circuits) take a while to kick in, so in practice we don't see houses either blowing their main fuses or melting/drooping PVC cables all over the place.
There's also a difference between a single-family house - the case you've suggested here - and "houses in multiple occupation", i.e. converted into flats/bedsits. For a bedsit conversion, it's more likely that there'll be multipe fanheaters/hairdryers/kettles and all sorts going on at once - in the evening as the occupants come home, say - and Good Practice says you apply lower "diversity" factors (that's RegSpeak for "not all the possible loads will be on at once") in such a case, or in a school domestic science "lab" where all cookers/oven/baby-Bellings *will* be on at once, than for a domestic installation.
HTH, Stefek
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On 26 Sep 2003 13:05:59 GMT, snipped-for-privacy@hp.com wrote:

uWaves have RF outputs in the 600 to 800W range but aren't that effcient at converting electrickery into RF. 1.5kW for an "800W" uWave isn't too far from the mark.
You mention the regs and diversity, calculating that correctly is what is important rather than simply adding up all the possible loads. TBH you can probably ignore most things that are not "heaters" as they won't take that much power, allow a few kW for them. It's the biggies like water heaters (from washing machines, through kettles and immersions to showers) and space heating that really determine the maximum load.
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Thanks, Stefek, this was most helpful.
I went round the house and switched various loads on and off. I measured the "with load" and "without load" current through the live incomer using a Fluke clamp meter. I recorded the following readings (difference between "with" and "without"):
Tumble dryer = 11.9A average, 16.0A peak Dishwasher = 13.6A for at least 10 mins Electric cooker (two ovens on full, no rings on) = 18.7A Electric cooker (four rings on full, no ovens on) = 25.3A Microwave oven (Cat D) = 7.0A Electric kettle = 9.2A Toaster (two slice) = 3.1A Hair Dryer = 7.3A All lights on (40 bulbs) = 11.6A Electric fan heater on full = 11.6A Washing machine = [still to test]
The point of my original post was not how expensive or inefficient it would be to use all the above at the same time. It is that, worst case, you could conceivably consume near the 100A single phase limit with standard appliances.
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