Sanity Check Required - Do I really need 3 Phase Upgrade?

[JohnW2]

Becuase it's not!; One can not call it 2 phase without then being 180° out of phase from each other.

Well, people might (and do) quibble about what is meant by "180° out-of-phase" - but, by my reckoning, they are!

Even those who call it 'split phase' are implicitly accepting that there are 'two phases'. If you don't believe that the two 240V supplies one can derive from a 240-0-240 feed are 180° apart, what do you think the phase difference between them is??

Kind Regards, John

 

[deadshort]

Or the electrican does not want the job!

DS

 

[JohnW2]

Or the electrican does not want the job!

It would seem that he's already taken on the job, and has already completed much of it!

Kind Regards, John

 

[PBC_1966]

Going back even further, we used to have red, blue and green phase,

Once again, not affecting installations within buildings, but I believe that at least one of the pre-nationalization companies used white for neutral along with red/blue/greeen phases on its outside plant. (And for those not already aware of it, white has long been the standard color for neutral here in the United States.)

If you don't believe that the two 240V supplies one can derive from a 240-0-240 feed are 180° apart, what do you think the phase difference between them is??

//www.diynot.com/diy/threads/single-phase-2-phase-3-phase-etc.437581/page-5

 

[eveares]

philnixon, could you do us lot on here a favour; show the link below to your electrician and get him to read the page.

https://www.tlc-direct.co.uk/Book/6.2.3.htm

 

[securespark]

Was I ?

Yes, you were.

Doubt it.

Sure about that ?

99% certain.

That'll be "No", then.

Are you denying you ever wrote anything about that?

I'm not denying that I ever wrote anything related to that subject.

But I am denying that I said what you seem to think I did. But feel free to show that I'm wrong in that.

Why so defensive?

Why not just tell me what you did say?

 

[RF Lighting]

They used to be! Red, white and blue (how patriotic!) were permitted as standard colours for three phase supplies up until 1966.

Yes, I chose to write red/white/blue as many of the d.c. to a.c. conversions were carried out during that era, but some would have been done after white changed to yellow.

Not that the electricity boards necessarily followed immediately, but the change for installations in the IEE Regs. specified yellow after 1st August 1964. White continued to be permitted for flexible cords & cables to 1st April 1971.

From 13th edition as amended to 1963, original 14th edition 1966, and revised 14th edition 1970:

View attachment 91828 View attachment 91827 View attachment 91826

Yes, but 240V x 2 = 480V. Paul was talking about a 240-0-240 three-wire 'split phase' supply (which people don't like me calling '2-phase', even if that's what BS7671 now calls it!) which still exists in some places in the UK

Yes, 240/480V systems are still not at all unusual in rural areas; I can think of at least half a dozen such systems within a few miles of where I used to live. The majority of homes get a standard 2-wire 240-volt connection, but for exceptionally heavy loading you could bring in both poles of the supply on a 3-wire service, just to balance the load.

which is analogous to thy 120-0-120 supply which I believe is very common in the US.

Indeed, it's been the standard supply system for residential and light commercial service for many decades, except that here it's the norm for all properties to get the full 3-wire service so that heavier loads within the building can operate on 240V.

Found this cutout on a job not far from me. It looks to be a repurposed old DC supply.

Also here's some RWB cable found on a recent job.

 

[JohnW2]

Also here's some RWB cable found on a recent job.

Does that count as 'white'? If there is any insulation at all (I was not initially sure!) it looks like 'transparent' rather than coloured at all.

Kind Regards, John

 

[RF Lighting]

I suppose it is transparent! It's definitely insulated.

 

[ban-all-sheds]

What's this "still"?? Has anyone, from my very first post onwards, ever suggested that?

No, but that doesn't mean that there was nobody thinking it.

 

[ban-all-sheds]

Why so defensive?

Well, excuse me, I'm sure, for "defending" myself against false allegations.

Why not just tell me what you did say?

I've said all sorts of things in 54,000+ posts.

Here are 3 randomly chosen ones:

Am I the only one who, when installing something new, or rewiring, always pushes a goodly length of "spare" cable into a ceiling or floor void, "just in case"?

Could be the site mangling URLs

Paste this into the search box on ebay: (metrel,robin,fluke,megger) (installation,multifunction) tester

which people don't like me calling '2-phase'

Becuase it's not!;

Yes it is.

One can not call it 2 phase without then being 180° out of phase from each other.

But as they are 180° apart then, as you say, one can call it 2-phase.

Was there something particular you wanted me to tell you I said?

It really would be much simpler for you to find what you think I said rather than me trying to guess which posts in which I did not say it should be repeated.

 

[securespark]

Trying to be clever results in you looking stupid.

Was there something particular you wanted me to tell you I said?

You know there is. I asked you about what you said about the 26A on a 20A breaker subject.

You know what you said and I don't know why you are reluctant to repeat it.

 

[ban-all-sheds]

I expect I said something along the lines of if you find, when you are doing your design, that your design current is 26A then you should not choose a 20A device.

Why you find that so unacceptable that you have to pursue me from thread to thread over it IHNI.

 

[PBC_1966]

Found this cutout on a job not far from me. It looks to be a repurposed old DC supply.

And judging by the condition of those tails, it looks as though they're about the same age as the cut-out.
Presumably the old positive fuse is still live with a second a.c. phase now.

Also here's some RWB cable found on a recent job.
View attachment 91850

Interesting - Don't think I ever came across triple like that where the "white" core is actually transparent instead of opaque white.

 

[securespark]

I expect I said something along the lines of if you find, when you are doing your design, that your design current is 26A then you should not choose a 20A device.

Why you find that so unacceptable that you have to pursue me from thread to thread over it IHNI.

I think we have both been guilty of not letting things go...

In the case of a socket circuit, it is difficult to allow for all scenarios when designing a circuit. Therefore I feel there is always a possibility of end users overloading a socket circuit.

But, and I think this is where we differ, I feel that if you think like that, you would never install a 20A socket circuit.