tegwin
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| posted on 4/4/07 at 10:41 AM |
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OT..house electrical supplies?
Im looking at putting a three phase supply to my house to power a german built heatpump...
In the heatpump manual is says it wants a 400V 3ph supply....
Does this mean that L1, L2, and L3 are 400v, or that they are 130V each?..?.
Is a UK 3ph supply 400V? and if so, how do I use that to power my exsiting 230V house?
Argh...its so damn confusing!
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nitram38
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| posted on 4/4/07 at 10:47 AM |
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No!
A 3 phase supply is 415V between phases and each phase is 240v between phase and neutral.
I hope you have deep pockets as your electricity supplier will charge anything from £1500 to £5000 to install. They will also install a 3 phase
meter, which will cost you more.
Why a 3 phase pump for a house?
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Sporty
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| posted on 4/4/07 at 10:47 AM |
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400v 3 ph is 230 v per phase. To power the house you just use take one phase connection off the 3 ph supply. Don't underestimate how much 3
phase is going to cost you to get put in.
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tegwin
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| posted on 4/4/07 at 10:53 AM |
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Im just looking at possiblities here...nothing is set instone...
The problem is, that the heatpump required to heat the house is quite large, and they only make three phase heatpumps of that size....
There is no harm in getting a quote from the power company for a three phase supply...
But once the installation is done, I assume they will only charge for the electricity we use, and wont charge other fees just because we are running
3ph?
And would I be correct in assuming, that as the house idealy needs 60A and the heatpump requires 25A that I should be getting a threephase supply
capable of supppling atleast 70A per phase? (or can I get a smaller supply and divide the house load between the phases?
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Sporty
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| posted on 4/4/07 at 10:54 AM |
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As for the difference between 400v and 415v or 230v and 240v there isn't one as all electricity supply voltages vary with system load. The UK
used to be 240v + or - 6% with european harmonisation it went to 230v + 10% - 6% classic european bodge job. No electrical equipment or supplies were
changed.
Your pump will work fine in the UK so all you have to worry about is cost.
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nitram38
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| posted on 4/4/07 at 10:58 AM |
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You can buy single phase to 3 phase converters but they will cost more to run.
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Sporty
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| posted on 4/4/07 at 10:58 AM |
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The 3 ph will cost you more in standing charge just look at one of the suppliers websites for costs. Take the minimum size you can get usually 60A it
will do fine and take the house off just one of the phases. You will need a competent electrician to do it as well due to the new part P regs and the
Electricity company required certification
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MikeRJ
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| posted on 4/4/07 at 11:43 AM |
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As far as I know you can not (or should not!) distribute a dometsic supply accross more than one phase.
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Bob C
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| posted on 4/4/07 at 12:17 PM |
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If the 3 phase is just for the heatpump compressor motor, you could use a large inverter, single phase input units are available up to about 4kW,
these would probably run 5.5kW in a heatpump. The other proviso is that the motor terminal box will let you connect in delta so you can get full
torque - most motors that size are wired like this nowadays.
You'd need to wire it to the electric cooker/shower supply....
Bob
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bartonp
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| posted on 4/4/07 at 12:44 PM |
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Discussion on ground source heat pumps (~ 2kW?)
http://tinyurl.com/2tx6gv
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tegwin
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| posted on 4/4/07 at 12:48 PM |
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Chears guys.
Spoke to the power company and indeed they do want silly money not only for installation but to provide the service...
So I spoke to a company who specialise in sold state 415V 3ph inverters....
They can supply a single box for a heap of cash that will happily feed straight into the contactors in the heatpump...I can then run the heatpump
controls of an un-inverted normal single phase supply...
Although the inverter is expensive, it doesnt waste a huge amount of energy...
Looks like a good possibility
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iank
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| posted on 4/4/07 at 01:30 PM |
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quote:
Originally posted by MikeRJ
As far as I know you can not (or should not!) distribute a dometsic supply accross more than one phase.
I believe you are correct in that it's probably illegal. I'm sure I was told in a previous company that each floor (at least) must be on
the same phase. I'd expect all the power in a domestic situation to be on the same phase (though different houses in the same street will vary
which phase they are connected to IIRC).
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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nitram38
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| posted on 4/4/07 at 01:36 PM |
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quote:
Originally posted by iank
quote:
Originally posted by MikeRJ
As far as I know you can not (or should not!) distribute a dometsic supply accross more than one phase.
I believe you are correct in that it's probably illegal. I'm sure I was told in a previous company that each floor (at least) must be on
the same phase. I'd expect all the power in a domestic situation to be on the same phase (though different houses in the same street will vary
which phase they are connected to IIRC).
Sorry boys, you are both completely wrong!!!!!!!!!
No regulation exists that says you can't have 3 phase anywhere as long as the correct installation methods are used and warnings
stickers/labels are on the relevent equipment.
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iank
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| posted on 4/4/07 at 01:52 PM |
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quote:
Originally posted by nitram38
quote:
Originally posted by iank
quote:
Originally posted by MikeRJ
As far as I know you can not (or should not!) distribute a dometsic supply accross more than one phase.
I believe you are correct in that it's probably illegal. I'm sure I was told in a previous company that each floor (at least) must be on
the same phase. I'd expect all the power in a domestic situation to be on the same phase (though different houses in the same street will vary
which phase they are connected to IIRC).
Sorry boys, you are both completely wrong!!!!!!!!!
No regulation exists that says you can't have 3 phase anywhere as long as the correct installation methods are used and warnings
stickers/labels are on the relevent equipment.
Not quite what we said. Are you really saying it's OK to have have different single phase 13 amp sockets in the same room running from
different phases? That is just plain dangerous.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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nitram38
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| posted on 4/4/07 at 02:17 PM |
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I am not going down the he said we said route. There are too many "experts" here sometimes.
What you are talking about has nothing to do with the original question of a 3 phase supply to domestic premises.
I have been an electrician for 27 years.
No regulation exists that says you can't have the different phases in one property or even that it has to be on different floors.
Like I said, if you use the correct installation methods (which I think covers good working practice regarding sockets adjacent to each other) and
warning labels etc it is ok.
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iank
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| posted on 4/4/07 at 02:42 PM |
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quote:
Originally posted by nitram38
I am not going down the he said we said route. There are too many "experts" here sometimes.
What you are talking about has nothing to do with the original question of a 3 phase supply to domestic premises.
I have been an electrician for 27 years.
No regulation exists that says you can't have the different phases in one property or even that it has to be on different floors.
Like I said, if you use the correct installation methods (which I think covers good working practice regarding sockets adjacent to each other) and
warning labels etc it is ok.
I certainly am responding to the original question:
quote:
And would I be correct in assuming, that as the house idealy needs 60A and the heatpump requires 25A that I should be getting a threephase supply
capable of supppling atleast 70A per phase? (or can I get a smaller supply and divide the house load between the phases?
Now if you say there is no regulation against it I'm certainly not going off to try to prove you wrong. But I was certainly told this
wasn't legal by a qualified electrician 15 years ago while he was installing a 3 phase robot controller.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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MikeRJ
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| posted on 4/4/07 at 03:16 PM |
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quote:
Originally posted by nitram38
No regulation exists that says you can't have the different phases in one property or even that it has to be on different floors.
No regulation exists to say I must always wear goggles when using my angle grinder, but I'd be stupid if I didn't.
The point being having multiple phases on sockets in close proximity to each other is a safety risk, and even splitting across floors in a domestic
situation were extension leads are often likely to be used doesn't seem too clever.
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nitram38
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| posted on 4/4/07 at 04:05 PM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by nitram38
No regulation exists that says you can't have the different phases in one property or even that it has to be on different floors.
No regulation exists to say I must always wear goggles when using my angle grinder, but I'd be stupid if I didn't.
The point being having multiple phases on sockets in close proximity to each other is a safety risk, and even splitting across floors in a domestic
situation were extension leads are often likely to be used doesn't seem too clever.
Whatever you "think" is correct is not necessarily correct either.
As to the googles comment, if you are at a place of work not wearing googles and a hse officer saw you, you can be fined.
It is not "illegal" to put 2 sockets next to each other carrying different phases.
You can do this providing that they are installed correctly and have the correct warning labels.
All though this is not good practice, it is not "illegal".
Show me where it says this in the IEE regs.
[Edited on 4/4/2007 by nitram38]
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iank
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| posted on 4/4/07 at 04:31 PM |
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Found a reference pretty quickly which seems to imply separation of phases was a requirement before 16th edition came in:
http://www.abtt.co.uk/forums/index.php?s=a6245ac84f02e93d9a877dfb650674d3&showtopic=970&st=0&#entry4416
See the post by someone called gareth:
quote:
It's not a question of there being a document that says "you can" - more one of there no longer being a document that says
"you can't". There used to be a section concerning phase separation in the IEE wiring regulations, but that part of the regs
disappeared with the 16th edition.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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Bob C
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| posted on 4/4/07 at 05:18 PM |
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shouldn't be silly money - should be a couple of hundred - eg
http://uk.farnell.com/jsp/Industrial+Controls+&+Automation/Motor+Drives/OMRON/CIMR-V7AZB4P00/displayProduct.jsp?sku=3181704
OK it's silly money from the catalogs..... & the cheaper suppliers (mitsy, siemens) didn't have a 4kW in farnell
Bob
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nitram38
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| posted on 4/4/07 at 05:32 PM |
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quote:
Originally posted by iank
Found a reference pretty quickly which seems to imply separation of phases was a requirement before 16th edition came in:
http://www.abtt.co.uk/forums/index.php?s=a6245ac84f02e93d9a877dfb650674d3&showtopic=970&st=0&#entry4416
See the post by someone called gareth:
quote:
It's not a question of there being a document that says "you can" - more one of there no longer being a document that says
"you can't". There used to be a section concerning phase separation in the IEE wiring regulations, but that part of the regs
disappeared with the 16th edition.
The 16th edition came in 23 years ago.
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iank
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| posted on 4/4/07 at 05:40 PM |
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So can you remember what 15th edition said about phase separation? Seems my source was still hanging on to the wisdom from his original training 
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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MkIndy7
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| posted on 4/4/07 at 05:56 PM |
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25A... that must be 1 hell of a pump!
A 3 to 4" heating circulating pump for a commercial premisis only draws about 10 amps max.
Is the 25A Just a start up current?
in which case if started slowy by and inverter it would be much less.
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nitram38
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| posted on 4/4/07 at 06:23 PM |
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quote:
Originally posted by iank
So can you remember what 15th edition said about phase separation? Seems my source was still hanging on to the wisdom from his original training
Unfortunately I can 
Most segregation applied to multiple way switches, where there could be several circuits on different phases.
This had more to do with installation circuit crossover mistakes and risk to the electrician if he opened up a live switch, rather than a hazard to
the consumer.
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DIY Si
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| posted on 4/4/07 at 07:08 PM |
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The only place I've ever seen 2 or more phases used in one house is where one is feeding storage heaters, and even that doesn't happen too
often. Only really big houses/industrial places need 3 phases, as 1 is good for 100A in most areas.
If you can find a way of not using 3 phase, I'd go that way as I know what BG charge for theirs! It'll take ages to get put in and cost a
fortune. If you're careful a single phase for the house will do fine, unless you want loads of power showers/storage heaters and big electrical
gear.
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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