B&O mains wiring confusion. - UK Vintage Radio Repair and Restoration Discussion Forum

sobell1980 · 1st Mar 2019, 8:06 pm

Hi all

Just wiring up my Beomaster amp and am faced with continental blue and black mains wires. I've read conflicting advice . Some say the Blue is neutral and some say the Blue is line voltage depending on what sources you read. I'm sure if on the continent it was fitted with a two pin plug so could work either way round. But for my sanity which is the correct way? I'm with black being Live and and blue neutral. Can anyone clear this up?
Dave

TonyDuell · 1st Mar 2019, 8:13 pm

Black is a colour assigned to 'live' wires on the continent, so I'm with you. Blue is neutral, Black is live. But I doubt it matters.

[An aside : The old colours for fixed wiring in the UK were black neutral and red, yellow, blue as the live colours (on 3 phase mains). The new ones are blue neutral and brown, black, grey as the 3 phase lives. When the change happened I asked an electrical engineer how I would lnow if a single phase part of an installation was old colours, blue phase (so blue llve, black neutral) or new colours, black phase (so blue neutral, black live). His reply was 'You measure it' (i.e the voltage between each conductor and earth) 'which I would strongly advise you to do in any case' ]

G6Tanuki · 1st Mar 2019, 9:30 pm

Sur le continent (and in the USA, Central America, Japan etc), they've historically been much more liberally-minded and flexible compared to us narrow-minded and authoritarian British with our rigid ideas of '"live and neutral'" - plenty of 'global market' power-plugs are unpolarised, and lots of their gear came with 2-core flexes with no colour-coding.

So, to be honest, I wouldn't worry yourself unduly about which wire goes to which pin!

sobell1980 · 1st Mar 2019, 10:37 pm

Fair enough. Thank you for the replies. Just for the record I've gone black to live and blue to neutral. Just needed a sanity check today.
Many thanks.
Dave

Marconi_MPT4 · 2nd Mar 2019, 5:27 pm

Hi,
Often used to be asked this question regarding B&O equipment. Agree that blue is neutral and black is live. Many customers cut off the European two pin moulded plug and fitted a standard BS three pin type.

Although European countries had different configurations before the EU standardised on blue and brown, blue was always neutral.

A useful link showing old wiring standards. See table 'Old Fixed Cable Colours In European Countries' further down the page.

https://wiki.openelectrical.org/inde...le_Colour_Code

Rich

Tractorfan · 2nd Mar 2019, 6:05 pm

Hi,
For information:
I've done a fair bit of wiring in France, household as well as appliance, and here blue is always neutral (neutre), green/yellow is always earth (terre) and any other colour can be live (phase), but is often red, brown or black.
I'm sure the situation is similar in other European countries.
As mentioned earlier, polarity isn't considered important and I have a twin socket (earthed) where the polarity depends on which socket is used.
Cheers, Pete.

ben · 7th Mar 2019, 2:48 am

Same in Spain. Though I've never seen old mains cables with blue and black over here, a few black and red though.
These days at least circuit breakers are fitted to homes and there is less kit around with exposed metal parts! One has to be careful with vintage things like record players with U series valves, but I digress.

1st Mar 2019, 8:06 pm	#1
sobell1980 Octode Join Date: May 2011 Location: Bromyard, Herefordshire, UK. Posts: 1,241	B&O mains wiring confusion. Hi all Just wiring up my Beomaster amp and am faced with continental blue and black mains wires. I've read conflicting advice . Some say the Blue is neutral and some say the Blue is line voltage depending on what sources you read. I'm sure if on the continent it was fitted with a two pin plug so could work either way round. But for my sanity which is the correct way? I'm with black being Live and and blue neutral. Can anyone clear this up? Dave

1st Mar 2019, 8:13 pm	#2
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,224	Re: B&O mains wiring confusion. Black is a colour assigned to 'live' wires on the continent, so I'm with you. Blue is neutral, Black is live. But I doubt it matters. [An aside : The old colours for fixed wiring in the UK were black neutral and red, yellow, blue as the live colours (on 3 phase mains). The new ones are blue neutral and brown, black, grey as the 3 phase lives. When the change happened I asked an electrical engineer how I would lnow if a single phase part of an installation was old colours, blue phase (so blue llve, black neutral) or new colours, black phase (so blue neutral, black live). His reply was 'You measure it' (i.e the voltage between each conductor and earth) 'which I would strongly advise you to do in any case' ]

1st Mar 2019, 9:30 pm	#3
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: B&O mains wiring confusion. Sur le continent (and in the USA, Central America, Japan etc), they've historically been much more liberally-minded and flexible compared to us narrow-minded and authoritarian British with our rigid ideas of '"live and neutral'" - plenty of 'global market' power-plugs are unpolarised, and lots of their gear came with 2-core flexes with no colour-coding. So, to be honest, I wouldn't worry yourself unduly about which wire goes to which pin!

1st Mar 2019, 10:37 pm	#4
sobell1980 Octode Join Date: May 2011 Location: Bromyard, Herefordshire, UK. Posts: 1,241	Re: B&O mains wiring confusion. Fair enough. Thank you for the replies. Just for the record I've gone black to live and blue to neutral. Just needed a sanity check today. Many thanks. Dave

2nd Mar 2019, 5:27 pm	#5
Marconi_MPT4 Heptode Join Date: Mar 2011 Location: Dorset, UK. Posts: 522	Re: B&O mains wiring confusion. Hi, Often used to be asked this question regarding B&O equipment. Agree that blue is neutral and black is live. Many customers cut off the European two pin moulded plug and fitted a standard BS three pin type. Although European countries had different configurations before the EU standardised on blue and brown, blue was always neutral. A useful link showing old wiring standards. See table 'Old Fixed Cable Colours In European Countries' further down the page. https://wiki.openelectrical.org/inde...le_Colour_Code Rich __________________ To an optimist a glass is half full; a pessimist half empty; an engineer twice as big as need be!

2nd Mar 2019, 6:05 pm	#6
Tractorfan Dekatron Join Date: Mar 2008 Location: St. Frajou, l'Isle en Dodon, Haute Garonne, France.(Previously: Ellesmere Port, Cheshire, UK.) Posts: 3,184	Re: B&O mains wiring confusion. Hi, For information: I've done a fair bit of wiring in France, household as well as appliance, and here blue is always neutral (neutre), green/yellow is always earth (terre) and any other colour can be live (phase), but is often red, brown or black. I'm sure the situation is similar in other European countries. As mentioned earlier, polarity isn't considered important and I have a twin socket (earthed) where the polarity depends on which socket is used. Cheers, Pete. __________________ "Hello?, Yes, I'm on the train, I might lose the signal soon as we're just going into a tunn..."

7th Mar 2019, 2:48 am	#7
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: B&O mains wiring confusion. Same in Spain. Though I've never seen old mains cables with blue and black over here, a few black and red though. These days at least circuit breakers are fitted to homes and there is less kit around with exposed metal parts! One has to be careful with vintage things like record players with U series valves, but I digress. __________________ Regards, Ben.