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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#1
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Upgrade to a three phase domestic supply?
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 |
#2
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Upgrade to a three phase domestic supply?
Pandora wrote:
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? 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 |
#3
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Upgrade to a three phase domestic supply?
"Pandora" wrote in message om... 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 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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Upgrade to a three phase domestic supply?
"BigWallop" wrote in message ...
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.) |
#5
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Upgrade to a three phase domestic supply?
"Michael McNeil" wrote in message om... "BigWallop" wrote in message ... 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.) 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. 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? 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 --- -- Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.520 / Virus Database: 318 - Release Date: 18/09/2003 |
#6
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Upgrade to a three phase domestic supply?
BigWallop wrote in message ... snip 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. snip 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? |
#7
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Upgrade to a three phase domestic supply?
On Fri, 26 Sep 2003 12:37:56 +0100, "Pandora" wrote:
How do my load estimations look? 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 ? -- John Mail john rather than nospam... |
#8
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Upgrade to a three phase domestic supply?
"John Laird" wrote in message ... On Fri, 26 Sep 2003 12:37:56 +0100, "Pandora" wrote: How do my load estimations look? 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 ? Plus ignoring pulling 14.5A from a 13A plug on the drier... D |
#9
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Upgrade to a three phase domestic supply?
Pandora wrote:
How do my load estimations look? Like a complete load of ********? -- Regards Tony Hogarty (take out garbage to reply, any mail to this account over 3k in size is deleted at the server) |
#10
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Upgrade to a three phase domestic supply?
In uk.d-i-y, Pandora wrote:
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) 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. 14.5A (Tumble dryer) Not as high as that, but could be 12A, and unlike the washing machine will be sustained for a longer time - 60-90 minutes. 6A (Iron) 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... 1.5A (Fridge) 3A (Freezer) Unlikely to be that high for either, and again will be smoothed by thermostat action. 12A (Dishwasher) 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. 10A (Cooker (electric)) 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). 6A (Microwave oven) 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? 8A (Electric kettle) Yes, while it's on; but not for more than 4-5 minutes in an hour. 2A (Hi-Fi Stereo, surround sound system.) 2A (2 x Computer) 1A (2 x 17" monitor) 6A (Hair dryer) 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? 0.5A (TV) 1A (Computer) 0.5A (17" monitor) 2A (Shower pump) 2A (Extractor fan) Hmm, it's the cat in the shower? 12.5A (Immersion or water heater) 3.5A (Central heating pump) 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. 3A (Fan Heater 1/3hp) 10A (Lighting) Possible but profligate! 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? 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 |
#12
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Upgrade to a three phase domestic supply?
Well high. You make no allowance for diversity. Many of the ratings quoted
are well above the currents actually likely to be drawn. Also, they are peak currents. Most will only draw these for short periods, which are unlikely to be exactly coincident in time. Also, short transient currents above the rating are permitted. It is only if the current remains over the rated current for a long time (i.e. minutes) will it matter. 12.5A (Washing machine) Only whilst heating water, which might be for ten minutes at a time. Average current much lower. 14.5A (Tumble dryer) Again, average current is lower. The rating you give is actually above the 13A fuse, so is too high. 6A (Iron) Low duty cycle. Mine only comes on for a few seconds before cutting out for a minute. Average current much lower. 1.5A (Fridge) Again, low duty cycle. The compressor only comes on occasionally. 3A (Freezer) I don't believe a freezer would draw 3A on average. 12A (Dishwasher) Only whilst heating, which isn't very much. 10A (Cooker (electric)) If cooking a complex dinner, the average might exceed this. 6A (Microwave oven) Only for a couple of minutes. 8A (Electric kettle) Only for a couple of minutes. 2A (Hi-Fi Stereo, surround sound system.) Hope you don't have neighbours. That would produce about 125W rms per channel on a 50% efficient amplifier, which would blow your ears off, unless you wear baseball caps backwards. 2A (2 x Computer) 1A (Computer) Well over. The power supply is its maximum rating. It will only draw a fraction. 1A (2 x 17" monitor) 0.5A (17" monitor) Probably about right. 6A (Hair dryer) Only used for a couple of minutes at a time. 2A (Shower pump) Only used for a couple of minutes at a time. 2A (Extractor fan) Only used for a couple of minutes at a time. This rating will produce a hurricane. 12.5A (Immersion or water heater) Should only be used for backup. You do have central heating that heats the water? It is also thermostatically controlled, so isn't a constant load. 3.5A (Central heating pump) This is totally way over the top. Normally, the entire central heating system is fused at 3A. 3A (Fan Heater 1/3hp) That's a very little heater. However, it could be a reasonable average in a centrally heated home with thermostatic control. 10A (Lighting) Does this include floodlighting the football pitch? I have about 10 bulbs, with an average wattage of around 15W, giving 150W ~= 0.6A. Even if you have tonnes of halogen lighting, I'd be surprised to see a figure this high. This is 2.4kW of bulbs, or 24 100W bulbs, all on simultaneously. 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. This would absolutely covered by diversity calculations. You could probably squeeze it into a 60A supply. Remember, it doesn't matter if the instantaneous current exceeds 100A for a short period. It is the average current drawn over a period of minutes that counts. I doubt that these loads in actual use (rather than pathological timing) would actually exceed 60A). Christian. |
#13
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Upgrade to a three phase domestic supply?
Pandora wrote:
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 Would seem like overkill? If not electric heating would not 230 volt 100 amps be OK; unless it's a boarding house with people living, cooking/eating etc. in individual rooms? Reminds one of the old 'shilling in the slot meter' old old digs! Our four bedroom insulated wood frame 1530 sq. ft (main floor) plus full basement has the here standard 200 amp 115/230 volt supply. Wired over head from a pole mounted distribution transformer about 120 metres away. In this somewhat colder and longer heating season than the UK; we have electric baseboard heating with individual thermostats for each room/area. Thirty five gallon hot water heating tank, clothes dryer, dish washer, radios, TV, computers etc. Several other (about five IIRC) typical homes are supplied from the same distribution transformer. No voltage problems. Lights and wall plugs are 115 volt, 'heavy' items, viz. cooking stove (oven +4 hobs), water heater, electric heating is 230 volt. Basement workshop is mixture of 115, and 230 volt for occasional heater and bench saw. On a 24 hour average, cos never is everything 'ON' at once, the consumption is around 4-5 kilowatts per hour, often less. At a maximum, even if one comes home turns up the heat and put clothes on to wash, maybe boils the kettle for a few minutes etc. etc. I doubt if it ever goes up to the 'rated' maximum which in our case is 200 amps X 230 volts = 46,000 watts or 46 kilowatts! Suggestion. |
#14
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Upgrade to a three phase domestic supply?
"Pandora" wrote
| 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. | 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. About the only requirement for 3 phase (as others have subsequently illustrated with their demand calculations) in a single family household is if there is a high storage space heating and storage hot water load, as all these would come on simulataneously during the off-peak time and there is no diversity applicable. In a house which is subdivided into bedsits etc, or used as B&B with lots of electric instantaneous showers, or if you run a pottery kiln etc, then things are different. Owain |
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Upgrade to a three phase domestic supply?
On Fri, 26 Sep 2003 01:55:27 UTC, "BigWallop"
wrote: 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. Perhaps he has a wife and seven daughters who all have ensuite showers and want to use them at the same time.... :-) -- Bob Eager rde at tavi.co.uk PC Server 325*4; PS/2s 9585, 8595, 9595*2, 8580*3, P70... |
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Upgrade to a three phase domestic supply?
Steve wrote:
Pandora wrote: 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? 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. 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. -- Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at www.diyfaq.org.uk Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html |
#17
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Upgrade to a three phase domestic supply?
In message , Pandora
writes 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? It looks like a bit of time budgeting might be in order -- geoff |
#18
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Upgrade to a three phase domestic supply?
And 2300W of lighting ?
Hell, I have 540W of lighting in the kitchen alone :-} -- Please add "[newsgroup]" in the subject of any personal replies via email * old email address "btiruseless" abandoned due to worm-generated spam * --- My new email address has "ngspamtrap" & @btinternet.com in it ;-) --- |
#19
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Upgrade to a three phase domestic supply?
"Colin Wilson" wrote in message t... And 2300W of lighting ? Hell, I have 540W of lighting in the kitchen alone :-} But is it Low Voltage Dichroic Lighting or Incandescent Lamps or GLS or Flourescent or Halogen or ? ? ? --- www.basecuritysystems.no-ip.com Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.521 / Virus Database: 319 - Release Date: 23/09/03 |
#21
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Upgrade to a three phase domestic supply?
"Pandora" wrote in message t...
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: 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? You seem to think that people have at least 4 hands each and do in fact do 2 3 or 4 things at once. Others have commented on diversity. 12.5A (Washing machine) 14.5A (Tumble dryer) 1kW is more likely. 6A (Iron) 2-4A 1.5A (Fridge) not many eating 360w nowadays. 3A (Freezer) try 65-150w 12A (Dishwasher) 10A (Cooker (electric)) may be much higher 6A (Microwave oven) 8A (Electric kettle) more likely 12 or 13A 2A (Hi-Fi Stereo, surround sound system.) try 20-50w 2A (2 x Computer) may be higher 1A (2 x 17" monitor) 6A (Hair dryer) thats more like a paint melting gun 0.5A (TV) 1A (Computer) 0.5A (17" monitor) 2A (Shower pump) 500w?? no, closer to a tenth that 2A (Extractor fan) more ike 20 or 30w than 500 12.5A (Immersion or water heater) 3.5A (Central heating pump) divide that by 10. When the house is eating 100A theres no way the CH will be on 3A (Fan Heater 1/3hp) as well as cookers and all the other loads? 240v 100A is already 24kW. 10A (Lighting) 5A (Sundry electrical loads) IRL you'd cook before exceeding a 100A house supply. Lots of places still run happily on 40A supplies. Regards, NT |
#22
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Upgrade to a three phase domestic supply?
And 2300W of lighting ?
Hell, I have 540W of lighting in the kitchen alone :-} But is it Low Voltage Dichroic Lighting or Incandescent Lamps or GLS or Flourescent or Halogen or ? ? ? 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 -- Please add "[newsgroup]" in the subject of any personal replies via email * old email address "btiruseless" abandoned due to worm-generated spam * --- My new email address has "ngspamtrap" & @btinternet.com in it ;-) --- |
#23
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Upgrade to a three phase domestic supply?
"IMM" wrote in message ...
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 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. |
#24
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Upgrade to a three phase domestic supply?
We have 3 phase already in our chapel - being converted to house and
workshop. I am keeping it as I am a woodworker and have some 3 phase machines - and future machines bought will be much cheaper if 3 phase, second hand that is, not much difference in new prices. Also, having a large workshop I could for instance accomodate a potter with a large kiln which would definitely need 3 phase. Except for these considerations 3 phase is unecessary and no normal domestic set-up is ever likely to exceed 100amps. However the problem remains - what considerations are there with respect to re-wiring in 3 phase. I'm ok with single phase wiring and I know about spreading the load between phases but are there any particular problems or no-nos, or good sources of info? cheers Jacob |
#25
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Upgrade to a three phase domestic supply?
"Michael McNeil" wrote in message om... "IMM" wrote in message ... 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 Excellent sites well the first one was excellent except that it gave no clear idea of the size weight and price. Whispergen is available, so see a dealer. Ditto the other one but I couldn't get on with the way the pictures loaded. The Microgen is available next Spring. I'd never heard of the stirling engine http://www.stirlinginfo.com/ 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. 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. 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. Why? It works on a different concept and operation to an IC engine. Get al the stuff out your head about IC engines. --- -- Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.520 / Virus Database: 318 - Release Date: 18/09/2003 |
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Upgrade to a three phase domestic supply?
"Colin Wilson" wrote in message t... And 2300W of lighting ? Hell, I have 540W of lighting in the kitchen alone :-} But is it Low Voltage Dichroic Lighting or Incandescent Lamps or GLS or Flourescent or Halogen or ? ? ? 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 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. --- www.basecuritysystems.no-ip.com Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.521 / Virus Database: 319 - Release Date: 23/09/03 |
#27
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Upgrade to a three phase domestic supply?
Hell, I have 540W of lighting in the kitchen alone :-}
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. 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 :-} -- Please add "[newsgroup]" in the subject of any personal replies via email * old email address "btiruseless" abandoned due to worm-generated spam * --- My new email address has "ngspamtrap" & @btinternet.com in it ;-) --- |
#28
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Upgrade to a three phase domestic supply?
"Colin Wilson" wrote in message t... Hell, I have 540W of lighting in the kitchen alone :-} 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. 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 :-} LOL Ah well ! If it's acting as emergency lighting, then it is better to have it as bright as possible. :-)) --- www.basecuritysystems.no-ip.com Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.521 / Virus Database: 319 - Release Date: 23/09/03 |
#29
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Upgrade to a three phase domestic supply?
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. |
#30
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Upgrade to a three phase domestic supply?
On 28 Sep 2003 08:21:22 -0700, Pandora wrote:
snip 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. Yes, but you really do need to try and grasp the principle of diversity. If you switch every single appliance in your house on the same time, it is very likely that you would exceed the maximum design ratings of the supply equipment or the installation. But, and it's a very big but, that load *will* fall off as thermostats start to operate. Electrical cables and mains fuses are more than capable of withstanding overloads (as distinct from faults) for short periods of time, although the installation fuses or mcb's may operate. It might surprise you to learn that the after-diversity maximum demand per dwelling on a non-electric heating estate of say 50 houses for design purposes could be a low as 1.5 to 2kva per dwelling, although each dwelling could have some 15 to 20kva of load installed! The mains distribution equipment installed will have a notional maximum load of 75 to 100 kva, not 750 to 1,000kva. |
#31
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Upgrade to a three phase domestic supply?
Wanderer wrote in message news Yes, but you really do need to try and grasp the principle of diversity. snip OK. After some reflection, I'll stay with a single phase supply. Thanks to all posters. |
#32
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Upgrade to a three phase domestic supply?
In uk.d-i-y, Pandora wrote:
OK. After some reflection, I'll stay with a single phase supply. Thanks to all posters. You're welcome; and thanks in turn for not taking umbrage at the relatively robust terms in which your knowledge was supplemented ;-) |
#33
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Upgrade to a three phase domestic supply?
In message , Pandora
writes Wanderer wrote in message news Yes, but you really do need to try and grasp the principle of diversity. snip OK. After some reflection, I'll stay with a single phase supply. Good idea -- geoff |
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