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  #1   Report Post  
Pandora
 
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Default 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   Report Post  
Steve
 
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Default 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   Report Post  
BigWallop
 
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Default 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.


  #4   Report Post  
Michael McNeil
 
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Default 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   Report Post  
IMM
 
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Default 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





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  #6   Report Post  
Pandora
 
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Default 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   Report Post  
John Laird
 
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Default 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   Report Post  
David Hearn
 
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Default 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   Report Post  
Tony Hogarty
 
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Default Upgrade to a three phase domestic supply?

Pandora wrote:

How do my load estimations look?


Like a complete load of ********?
--
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Tony Hogarty
(take out garbage to reply, any mail to this account over 3k in size is
deleted at the server)
  #10   Report Post  
 
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Default 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   Report Post  
Christian McArdle
 
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Default 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   Report Post  
Terry
 
Posts: n/a
Default 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   Report Post  
Owain
 
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Default 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




  #15   Report Post  
Bob Eager
 
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Default 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...



  #16   Report Post  
Ed Sirett
 
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Default 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   Report Post  
geoff
 
Posts: n/a
Default 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   Report Post  
Colin Wilson
 
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Default Upgrade to a three phase domestic supply?

And 2300W of lighting ?

Hell, I have 540W of lighting in the kitchen alone :-}

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  #19   Report Post  
BigWallop
 
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Default 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 ? ? ?


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  #21   Report Post  
N. Thornton
 
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Default 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   Report Post  
Colin Wilson
 
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Default 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

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  #23   Report Post  
Michael McNeil
 
Posts: n/a
Default 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   Report Post  
jacob
 
Posts: n/a
Default 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   Report Post  
IMM
 
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Default 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.



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  #26   Report Post  
BigWallop
 
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Default 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.


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  #27   Report Post  
Colin Wilson
 
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Default 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 :-}

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  #28   Report Post  
BigWallop
 
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Default 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. :-))


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  #29   Report Post  
Pandora
 
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Default 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   Report Post  
Wanderer
 
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Default 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   Report Post  
Pandora
 
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Default 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   Report Post  
 
Posts: n/a
Default 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   Report Post  
geoff
 
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Default 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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