Three phase colour code

brown black and blue is NOT a standard 3 phase color code
it sounds like a flex intended for 2 lives and a neutral

currently british wiring is in a changeover
old code
red L1
yellow L2
blue L3
black neutral

new code
brown L1
black L2
grey L3
blue neutral

 

brown black blue is a continental standard for three phase. i cant remember where it originates from but i think it might be italy..?
and they go in that order.
brown being red
black being yellow
blue being blue

 

or, as plug indicated it could be bi-phase.
though it doesnt have to be flex.

i think some parts of poland and the czech (?) republic use bi-phase

 

Also what are the
relative benefits of Delta as opposed to star
configuration?

Main reason for a delta winding is that a neutral isn't necessary because the phases are balanced, so why have it? Also 3rd harmonics are attenuated.

 

Take a look at http://www.niceic.org.uk/downloads/WiringSupp.pdf for full info.

 

Your flex is fine, it has TWO blacks. Brown is L1, one Black is L2 and the other is L3, the Blue is the Neutral. This is a standard euro-type flex. Very soon, the second black will turn into a grey i would think.

 

Are you doing the full installation or just the motor end, I have come across every combination of connections using control cable,blue as phase, black as earth etc, also if it is SY type with an outer braid it is good practice to earth it using the correct gland.This type of cable has been in common use in industry for 20 years. I have never seen a 3ph induction motor with a neutral connection, star or delta the configuration is more about torque, small hp motors are usually star, bigger ones delta and even bigger - star/delta

 

Unless the installation is wired under the new colours i would sleeve brn blk blu as red yell blu.
Delta wiring gives max power on a 400 rated motor (generally over 2.2 KW)
If a motor is wired in star it is usually a dual voltage motor 230/400 and generally less than 2.2kw

 

Yup, a star config set of windings has a mid point, but no need for a neutral still

 

don't some motors start in star then switch to delta?

 

Yes usually found in large compressors and the like, star connection keeps the starting current down until a timer switches the contactors over to delta

 

Yup, but still no neutral needed

 

I do not know wherehalf the answer's come from but this is the future 3phase colours. BUT I MUST WARN PEOPLE I HAVE WORKED ON ITALIAN SHIPS WHERE THEY USE BROWN ON A THREE CORE CABLE AS EARTN.

 

I do not know wherehalf the answer's come from but
this is the future 3phase colours. BUT I MUST WARN
PEOPLE I HAVE WORKED ON ITALIAN SHIPS WHERE THEY USE
BROWN ON A THREE CORE CABLE AS EARTN.

no, it isnt.
you my friend are a moron. and you dont use scotch blocks outside. i really hope you arent a practising electrician as the public really are in danger...

 

Your flex is fine, it has TWO blacks. Brown is L1, one Black is L2 and the other is L3, the Blue is the Neutral.

If Frere had 1 Brown, 2 Blacks and 1 Blue, I wonder why he tried to mislead us all by saying that he had Brown, Blue, Black & Green/Yellow?

 

BAS - well spotted

I was sure he said 2 blacks, and we work with this on a regular basis

 

if you get 2 phases swapped motors will run backwards

apparently this is such a problem with some 3 phase systems that you can buy (can't remember where i saw it but it was either RS or FARNELL) 3 phase CEES where you can use a small screwdriver to swap two of the phase pins to make your equipment turn the right way with the socket you are using