Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Martin Brown <'''newspam'''@nonad.co.uk>
Newsgroups: sci.electronics.design
Subject: Re: energy in UK
Date: Sat, 19 Apr 2025 17:20:42 +0100
Organization: A noiseless patient Spider
Lines: 48
Message-ID: <vu0igr$1q5ct$1@dont-email.me>
References: <6cblvjtuqq506j5l5uvvrkvcvj549klff8@4ax.com>
 <vtfhp7$25gv3$1@dont-email.me> <vtipp3$13511$1@dont-email.me>
 <vtka2s$2g8en$3@dont-email.me> <vtme4n$f4pp$1@dont-email.me>
 <vtmmh7$mjlu$1@dont-email.me> <vtnvoa$1vdsp$1@dont-email.me>
 <vtpc6n$35tke$1@dont-email.me> <vtqgc6$b177$1@dont-email.me>
 <vtqkca$b9gt$2@dont-email.me>
 <1raxpc1.wxxc7n63qcuuN%liz@poppyrecords.invalid.invalid>
 <2r58dlxrps.ln2@Telcontar.valinor> <vtrqqm$1ekr6$2@dont-email.me>
 <fqi8dlx1tv.ln2@Telcontar.valinor> <vtt1vb$2icra$1@dont-email.me>
 <vtuhs6$3s37s$4@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Sat, 19 Apr 2025 18:20:43 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="8cb3ed35b7fca93c3292ced5a3a12ae9";
	logging-data="1906077"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18xgQ0+gDleEzt2tP7JHVxbk6794zEvlb9zUQMLFks5cw=="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:mwdbbFdoSpqgNPwSfEfXQJjQTEg=
Content-Language: en-GB
In-Reply-To: <vtuhs6$3s37s$4@dont-email.me>

On 18/04/2025 22:57, Don Y wrote:
> On 4/18/2025 1:19 AM, Martin Brown wrote:
>> Where I live in a rural backwater the mains is actually more like US 
>> style two phase and neutral rather than normal UK 3 phase. 
> 
> Our mains is actually a 240V center tapped configuration (thus, single 
> phase).
> There are two "hot" leads -- each 180 degrees out of phase with the other.
> The center tap is considered neutral.  It is typically bonded to earth
> at the load center.

That is the same as in small rural villages in the UK except that each 
house is only on one of the two phases at 240v. ISTR US and Japan put 
their aircon across the antiphase pair to get the power handling up.

> Ideally, loads in the house are balanced on the two "legs".  An open
> neutral connection is a recipe for disaster as the loads start to
> see unbalanced potentials.

Our village hall has both phases present on 100A circuits 240v. There 
are warnings and duplicate distribution blocks for each phase.

And also warnings for using mixed old Black/Red/Green and modern 
Blue/Brown/Yellow-Green mains cabling.

> Particularly problematic in homes where the earth connection wasn't
> present universally throughout.

Earth is mandatory in UK installations often a local earth copper spike 
nailed into ground at the premises and the shield of the underground 
cable. My electricity actually comes in as two overhead wires. This is 
now actually quite rare in the UK and only happens in rural villages.

>> This is a sore point with businesses that would like to use 3 phase 
>> equipment. Each village is across one pair of the 3 phase distribution 
>> line with a transformer ratio to give 240v output.

> Each *village*?  How is that balanced?  Luck??

Quite possibly. It seems to work fine. It can be fun if the phase that 
isn't one of ours drops out completely and ours stay good. So much kit 
today works fine on 100+ volts that you only notice there is a problem 
when you try to boil a kettle or put on an old fashioned filament lamp!


-- 
Martin Brown