bosch wiring colours on double oven .. help

Hi all,

just got a bosch double under oven, model HBN13n5.ob

the wiring diagram is missing for some reason. It says it will be stamped on the back of the unit, but they obviously forgot on this one. Bosch customer care wont tell me unless i'm a qualified electrician.. great.

Anyway, there are one blue, one black and an earth. I'd assume black is neutral and blue live, but from my days as a wireman i seem to remember blue AND black can be live... so i dont know which one to stick it on. I know that in current wiring regs blue is neutral, but black is also neutral isnt it on older systems? Likewise, blue was used to indicate phase, so you can see why i'm confused !
Note that this is not a cable, its internal wiring so may well not follow the same rules as cabling colours.

So, can anyone help? which would it be?

what are you trying to do that you need to mess with internal wiring?

Hi Maxxy,

i'm not trying to mess with internal wiring, dont worry I just need to wire the supply to the cooker .. and those are the colours at the terminals under the back plate

Any markings on the terminal?

Best bet is phone customer services again - you will probably get a different person who may answer your question. Or just blag it and say your a sparky whose been called in to wire one up, but theres no wiring diagram.

Have you checked the manual?

If its a brand new cooker, its likely that Black is phase, and Blue is neutral, as this is the new colours. They should have used Brown as phase though to avoid confusion. Its best not to make assumptions though, but to get a definite answer from the suppliers of the cooker.

If customer servies refuse to tell you, then tell then that in that case, you havent received what you ordered - as its faulty goods if it doesnt include the safety manuals etc, and they should come and collect it. More than likely they will then sort it out!

finally managed to get through to bosch technical.

yuou were right.. Black is live, blue is neutral

They said that the markings are etched onto the terminal block, but they're definately not...
Anyway, all happy now.. ican finally wire it up after four days !