Is there 50+ year old electrician out there?

Post by **RogerRust** » Thu Nov 16, 2006 9:04 pm

I tripped over the lead to my battery charger today. I bought it in 1972 so that I could charge the 6 volt battery on my BSA. Any way thought I better check the wiring in the plug. In the dim garage I took the plug top off and took the wires out. Then I decided to take in in doors and rewire it in the warm.
Ok here's the intereasting bit, - three core flex - green/yellow must be earth, but the other two - one is blue the other is black.

I checked the earth is connected to the metal case but I can't see the other two because the box was spot welded from new to stop people like me getting inside!

Neither the black or blue show any connection to the case so I guess its insulated and the earth just earths the case. I connected black to live and blue to negative. It works fine, but I can't remember seeing this mixture of colours.

Post by **nebogipfel** » Thu Nov 16, 2006 9:16 pm

Was it manufactured somewhere other than the UK?

It's not the old or new UK standards.

Thinking about it (and bearing in mind I'm not an sparkie) Does it matter which way around you wire a transformer primary windings?

As long as you got the earth right

Post by **RogerRust** » Thu Nov 16, 2006 9:26 pm

Thats exactly what I decided! yes it is from the UK "Dencon ltd- 200-240 volts solid state" it says on the label

Post by **moggyminor16** » Fri Nov 17, 2006 8:38 pm

i would say that blue is live and the black neg

Post by **aupickup** » Sat Nov 18, 2006 1:11 pm

blue is live i would have said

Post by **moggyminor16** » Sat Nov 18, 2006 2:38 pm

yes in germany that use the same colour code and the blue is live

Post by **lowedb** » Sun Nov 19, 2006 9:51 am

yes in germany that use the same colour code and the blue is live

Not in the workshop I'm sat in. I've just been and looked at the distribution board, and blue is neutral, with the lives being black or brown and earth being green/yellow.
That would sort of tie in with the european standard for flexes(been around for years), and now for all wiring (came in over the last few years) being neutral blue.

Thinking about it (and bearing in mind I'm not an sparkie) Does it matter which way around you wire a transformer primary windings?

No. You can wire things both ways round as the supply is AC anyway. The reason you need to do it the right way is for switches and fuses. The easiest way is to give an example:
If there is a (mains) fuse inside the device and you wire it the 'wrong' way round then get a short circuit to the casing that blows the fuse, it would open the neutral line, and leave the casing still connected to live and hence potentially (pardon the pun) dangerous. Likewise if a device is switched off, but the switch is in the neutral wire, everything up to the point of the switch remains live, although it's apparently off. Aain this could be a problem. An absolute classic of this would be something like a table lamp, where the pins in the bulb holder would be live, even though the lamp is switched off.

Post by **moggyminor16** » Sun Nov 19, 2006 11:25 pm

Not in the workshop I'm sat in. I've just been and looked at the distribution board, and blue is neutral, with the lives being black or brown and earth being green/yellow.
That would sort of tie in with the european standard for flexes(been around for years), and now for all wiring (came in over the last few years) being neutral blue

yes very very very true but i was working putting new lights and sockets in a flat that was there before the war in hannover so i recon the person that owns the block of flats needs to do some fast rewiring dont you think