New Electricity Supply - Split Phase?
Discussion
Single phase.
We had a very strange "brownout" a number of years ago (our old Eddison lightbulbs went down to a barely visible brown light so I presume that is where the phrase comes from).
Turned out our "phase" has gone down due to gas contractors nicking the electric supply, you could look and down the road (7pm November) and see which houses were on the lost phase and it was pretty much the ratio 1:2. Fortunately the nearby Sainsburys local was even nearer the event and all phases had been lost and their fridges were off / freezers were defrosting. My wife came home with a load of milk and meat she'd got for free "to freeze and save for later".......then had an "ooops" moment realising all our big white good were off as well. Fortunately the freezing weather meant we could store the goods outside for the night until power was back.
We had a very strange "brownout" a number of years ago (our old Eddison lightbulbs went down to a barely visible brown light so I presume that is where the phrase comes from).
Turned out our "phase" has gone down due to gas contractors nicking the electric supply, you could look and down the road (7pm November) and see which houses were on the lost phase and it was pretty much the ratio 1:2. Fortunately the nearby Sainsburys local was even nearer the event and all phases had been lost and their fridges were off / freezers were defrosting. My wife came home with a load of milk and meat she'd got for free "to freeze and save for later".......then had an "ooops" moment realising all our big white good were off as well. Fortunately the freezing weather meant we could store the goods outside for the night until power was back.
Allegro_Snapon said:
Single phase.
Wikipedia would disagree with you:https://en.wikipedia.org/wiki/Split-phase_electric...
https://electricianforum.co.uk/threads/split-phase...
Mr Pointy said:
Allegro_Snapon said:
Single phase.
Wikipedia would disagree with you:https://en.wikipedia.org/wiki/Split-phase_electric...
https://electricianforum.co.uk/threads/split-phase...
eliot said:
Two phases of a three phase supply essentially
no its not., and this is the point. what you are saying here isnt the case and its the difference between 400 and 460v....With three phase 230 / 400 v supply you have three lives and a neutral. the lives are 120 degrees rotation between them.
source is usually an 11kv 3 phase supply thats stepped down to 230 / 400v for the consumer.
North America run similar with their 110 - 0 - 110 supplies. its what we call a centre tapped supply. the board primary supply is single phase HV which is stepped down.
our british supply is generally three phase.
connected in a star format. L1 L2 and L3 are 120 degrees apart hence 400v difference between the lines and not 460v
No going away from three phase to single phase, this is what 230 - 0 - 230 volt is.
It is basically a 460 volt secondary. with a centre tap. Do you have a power tool transformer ? those big yellow thingys ? Well its kinda like that. The transformer secondary there is 55 - 0 - 55. connection to the outer gives 110v centre tap is grounded to limit the voltage to earth to 55v which is safer.
Your 230 - 0 - 230 transformer supply comes to your house. Your not interested in 460 volts but 230 volts. so the utility incoming after the meter will split the supplies into two seperate 230v supplies. job jobbed. those supplies powering your house.
However you have to deal with the fact that you have 460v at your house. And if you have two circuits from different boards in close proximity you will have 460v between the lives.
TN-C-S refers to your earth - In the Uk the earth is derived from the neutral. Back at source the neutral is earthed to the mass of the earth through an earth rod or earth farm to tie it to the earth. TN-C-S means that the earth and neutral is combined right till your main board, where at the meter cut out its seperated.
Forget the usa system
UK split phase is 2 different phases red and yellow or red and blue or blue and yellow plus a neutral
or nowadays
Electrical Three Phase Wiring Colours
UK Old* UK New*
Phase 1 Red Brown
Phase 2 Yellow Black
Phase 3 Blue Grey
Neutral Black Blue
you have probably been quoted for split phase because of the load you have have asked for
or the supplier have guessed because you have said its for a barn ?
If you have split phase you can share the load over 2 phases rather than possibly overload 1 single phase , as I said it depends on what you have asked for load wise
UK split phase is 2 different phases red and yellow or red and blue or blue and yellow plus a neutral
or nowadays
Electrical Three Phase Wiring Colours
UK Old* UK New*
Phase 1 Red Brown
Phase 2 Yellow Black
Phase 3 Blue Grey
Neutral Black Blue
you have probably been quoted for split phase because of the load you have have asked for
or the supplier have guessed because you have said its for a barn ?
If you have split phase you can share the load over 2 phases rather than possibly overload 1 single phase , as I said it depends on what you have asked for load wise
Edited by x type on Sunday 26th March 22:05
x type said:
Forget the usa system
UK split phase is 2 different phases red and yellow or red and blue or blue and yellow plus a neutral
or nowadays
Electrical Three Phase Wiring Colours
UK Old* UK New*
Phase 1 Red Brown
Phase 2 Yellow Black
Phase 3 Blue Grey
Neutral Black Blue
you have probably been quoted for split phase because of the load you have have asked for
or the supplier have guessed because you have said its for a barn ?
If you have split phase you can share the load over 2 phases rather than possibly overload 1 single phase , as I said it depends on what you have asked for load wise
Who said it's anything to do with the USA system? One of the links I posted was from UK forum & the Wikipedia link has separate sections for the USA & Europe/UK. If it was two out of three phases why would the DNO describe it a Split Phase instead of two phases?UK split phase is 2 different phases red and yellow or red and blue or blue and yellow plus a neutral
or nowadays
Electrical Three Phase Wiring Colours
UK Old* UK New*
Phase 1 Red Brown
Phase 2 Yellow Black
Phase 3 Blue Grey
Neutral Black Blue
you have probably been quoted for split phase because of the load you have have asked for
or the supplier have guessed because you have said its for a barn ?
If you have split phase you can share the load over 2 phases rather than possibly overload 1 single phase , as I said it depends on what you have asked for load wise
Do you have any particular qualifications in this area? You seem to be very sure that split phase isn't what several references have described it as being.
https://midsummerwholesale.co.uk/split-phase
https://www.electriciansforums.net/threads/480v-sp...
The nominal voltage numbers give a clue what you're getting - two 230V phases and one shared neutral.
As they talk about it being rated for 30kVA it probably couldn't manage 100A on one phase so they've rounded up to what two phases can manage (~130A combined in this case).
Guess it will end up effectively as two single phase supplies and you'll have to split your loads part on one and part on the other.
As they talk about it being rated for 30kVA it probably couldn't manage 100A on one phase so they've rounded up to what two phases can manage (~130A combined in this case).
Guess it will end up effectively as two single phase supplies and you'll have to split your loads part on one and part on the other.
x type said:
Forget the usa system
UK split phase is 2 different phases red and yellow or red and blue or blue and yellow plus a neutral
or nowadays
Electrical Three Phase Wiring Colours
UK Old* UK New*
Phase 1 Red Brown
Phase 2 Yellow Black
Phase 3 Blue Grey
Neutral Black Blue
you have probably been quoted for split phase because of the load you have have asked for
or the supplier have guessed because you have said its for a barn ?
If you have split phase you can share the load over 2 phases rather than possibly overload 1 single phase , as I said it depends on what you have asked for load wise
No its not. UK split phase is 2 different phases red and yellow or red and blue or blue and yellow plus a neutral
or nowadays
Electrical Three Phase Wiring Colours
UK Old* UK New*
Phase 1 Red Brown
Phase 2 Yellow Black
Phase 3 Blue Grey
Neutral Black Blue
you have probably been quoted for split phase because of the load you have have asked for
or the supplier have guessed because you have said its for a barn ?
If you have split phase you can share the load over 2 phases rather than possibly overload 1 single phase , as I said it depends on what you have asked for load wise
Edited by x type on Sunday 26th March 22:05
its a SINGLE PHASE SUPPLY the untility only has one phase and this is used to give a split phase to user. got nothing to do with THREE PHASES. period.
ruggedscotty said:
No its not.
its a SINGLE PHASE SUPPLY the untility only has one phase and this is used to give a split phase to user. got nothing to do with THREE PHASES. period.
Surely you realise that the underlying utility distribution is 3 phase? its a SINGLE PHASE SUPPLY the untility only has one phase and this is used to give a split phase to user. got nothing to do with THREE PHASES. period.
A '230V 0V 230V' supply is fairly obviously going to be fed by two phases underneath, but wired to give two independent single phase supplies.
No different from any other case of using a 3 phase as 3x single phase, ideally with the loads balanced.
This thing is likely going to end up as 3 cores, giving two 60A fused supplies each with its own distribution on the end and a 3 phase meter configured for split phase operation. It's not that rare a setup.
pquinn said:
Surely you realise that the underlying utility distribution is 3 phase?
A '230V 0V 230V' supply is fairly obviously going to be fed by two phases underneath, but wired to give two independent single phase supplies.
No different from any other case of using a 3 phase as 3x single phase, ideally with the loads balanced.
This thing is likely going to end up as 3 cores, giving two 60A fused supplies each with its own distribution on the end and a 3 phase meter configured for split phase operation. It's not that rare a setup.
Have you really not read any of the links? Split Phase is a very distinct form of supply which is not derived directly from the three phase distribution. The phases are 180° apart not 120° & the phase-to-phase voltage is 460V instead of the usual 400/415V, high enough to require separate distribution boards.A '230V 0V 230V' supply is fairly obviously going to be fed by two phases underneath, but wired to give two independent single phase supplies.
No different from any other case of using a 3 phase as 3x single phase, ideally with the loads balanced.
This thing is likely going to end up as 3 cores, giving two 60A fused supplies each with its own distribution on the end and a 3 phase meter configured for split phase operation. It's not that rare a setup.
pquinn said:
The nominal voltage numbers give a clue what you're getting - two 230V phases and one shared neutral.
As they talk about it being rated for 30kVA it probably couldn't manage 100A on one phase so they've rounded up to what two phases can manage (~130A combined in this case).
Guess it will end up effectively as two single phase supplies and you'll have to split your loads part on one and part on the other.
I think this explains it - the original quote was for a 60amp supply and I went back and asked for a 100amp supply - future proof etc.. this was when the split supply appeared.As they talk about it being rated for 30kVA it probably couldn't manage 100A on one phase so they've rounded up to what two phases can manage (~130A combined in this case).
Guess it will end up effectively as two single phase supplies and you'll have to split your loads part on one and part on the other.
Interestingly they also state;
NGED to supply and install approximately 140m 0f 3c 185mm wavecon from points B to C (run as a bunched
main L1 & L2 live L3 & Neutral run as neutral). Joint to approximately 22m of 95mm wavecon cable, terminate
into new 200A HDCO (fused at 100A) at point A. 185mm wavecon Cable to be run through customer installed
steel duct at point D.
185mm wavecon to be terminated at the sub pole to energise.
So it looks like a 200A supply but fused at 100A....once they've installed I was told I need to get a electricity supplier to put the meter etc. in and then they will energise the line...
BatForcePC said:
theboss said:
OP can you just give the national grid planner the URL for this thread?
LOL - I never knew this was going to be such an interesting topic!https://www.nationalgrid.co.uk/downloads-view-reci...
National Grid said:
Split-phase connections are derived from split-phase transformers or in some cases from
three-phase transformers connected in a split-phase configuration. The two phases operate
180° apart and, in a perfectly balanced system, no current flows in the neutral
Then you can look at all the various wiring schemes utilising a 3 phase cutout.three-phase transformers connected in a split-phase configuration. The two phases operate
180° apart and, in a perfectly balanced system, no current flows in the neutral
Edited by theboss on Monday 27th March 12:06
Prior to this thread, I'd blindly assumed "split phase" was 2 out of three phases. Seems it's more complex than that from the expert discussion above!
OP(BatForcePC) - for your purposes, I believe you will have 2 wires coming in and you can probably treat them as two distinct single-phase supplies. Normally you'd avoid having both wires powering things in the same room or even building (even if they are 180 degrees out of phase). Your electrician will need to divide the loads between them. e.g. you might have one wire powering your house and one powering a barn/outbuilding or EV.
OP(BatForcePC) - for your purposes, I believe you will have 2 wires coming in and you can probably treat them as two distinct single-phase supplies. Normally you'd avoid having both wires powering things in the same room or even building (even if they are 180 degrees out of phase). Your electrician will need to divide the loads between them. e.g. you might have one wire powering your house and one powering a barn/outbuilding or EV.
pquinn said:
ruggedscotty said:
No its not.
its a SINGLE PHASE SUPPLY the untility only has one phase and this is used to give a split phase to user. got nothing to do with THREE PHASES. period.
Surely you realise that the underlying utility distribution is 3 phase? its a SINGLE PHASE SUPPLY the untility only has one phase and this is used to give a split phase to user. got nothing to do with THREE PHASES. period.
A '230V 0V 230V' supply is fairly obviously going to be fed by two phases underneath, but wired to give two independent single phase supplies.
No different from any other case of using a 3 phase as 3x single phase, ideally with the loads balanced.
This thing is likely going to end up as 3 cores, giving two 60A fused supplies each with its own distribution on the end and a 3 phase meter configured for split phase operation. It's not that rare a setup.
A point of note, although not that important to the OP, for a true understanding it's not really sufficient to simply state there is a 180 degree phase shift in split phase supplies. It's an important point but often missed - L1 and L2 have a 180 degrees shift but only with respect to neutral. There is no phase shift between L1 and L2. A completely different setup both physically and electrically than "two independent single phase supplies".
Laplace said:
It's still a single phase supply as stated by ruggedscotty. The underlying utility distribution is moot. The split-phase supply is derived from a single center tapped transformer secondary, therefore it's a single phase.
A point of note, although not that important to the OP, for a true understanding it's not really sufficient to simply state there is a 180 degree phase shift in split phase supplies. It's an important point but often missed - L1 and L2 have a 180 degrees shift but only with respect to neutral. There is no phase shift between L1 and L2. A completely different setup both physically and electrically than "two independent single phase supplies".
Neutral is neutral. It doesn't have 'phase'. it's zero.A point of note, although not that important to the OP, for a true understanding it's not really sufficient to simply state there is a 180 degree phase shift in split phase supplies. It's an important point but often missed - L1 and L2 have a 180 degrees shift but only with respect to neutral. There is no phase shift between L1 and L2. A completely different setup both physically and electrically than "two independent single phase supplies".
L1 and L2 are opposite polarity, 180 degrees out of phase. They are a 460V supply centre tapped by Neutral, which is grounded at some point.
High power equipment can connect from L1 to L2 and run at 460V
Laplace said:
A point of note, although not that important to the OP, for a true understanding it's not really sufficient to simply state there is a 180 degree phase shift in split phase supplies. It's an important point but often missed - L1 and L2 have a 180 degrees shift but only with respect to neutral. There is no phase shift between L1 and L2. A completely different setup both physically and electrically than "two independent single phase supplies".
If there's no phase shift between L1 & L2 wouldn't that also mean there's no voltage difference?Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff