Silly things

[plugwash]

So a yellow 3 pin socket should have the pins marked L1, L2, and E,

IIRC a three pin 60309 connector should have two of the pins marked L and ⏚. The third pin should be unlabelled as it may be either a neutral connection or a second live connection.

The designers of the standard *could* have chosen to have different connectors for P+N+E supplies and 2P+E supplies, but they did not decide to do so. Presumably because they thought such a distinction would have caused more problems then it solved.

Yet most yellow cable seems to have a blue core, why?

I presume because as far as the cable manufacturers are concerned it's just two core cable with earth, the "default" colour code for that is brown, blue and green/yellow and there hasn't been strong demand to produce cable in an different combination.

Plus, the maker of a cordset doesn't know for sure what supply type it will be used on anyway. They may make an educated guess but it's still just an educated guess.

 

[ericmark]

Would you prefer ,brown, brown, green and yellow inside yellow flex?

Brown, Black, green/yellow. Point is there is no neutral so should not be a blue wire.

 

[pete01]

Brown, Black, green/yellow. Point is there is no neutral so should not be a blue wire.

But blue doesn't always mean neutral, put a brown sleeve on it.... maybe.

 

[ericmark]

But blue doesn't always mean neutral, put a brown sleeve on it.... maybe.

I could see the point if having split supplies was rare, but there must be many more 100's of meters of yellow flex which should be brown, black, green/yellow to having brown, blue, green/yellow, so why not over sleeve the black with a blue sleeve?

 

[pete01]

I could see the point if having split supplies was rare, but there must be many more 100's of meters of yellow flex which should be brown, black, green/yellow to having brown, blue, green/yellow, so why not over sleeve the black with a blue sleeve?

Could do I suppose never really thought about it before

 

[ebee]

Not that long ago some European flexes had 5 cores as Brown/Black/Black (again) for three phases and d Blue for N then the fifth core was earth.
Two Blacks for two different phases! The mind boggles

 

[pete01]

Not that long ago some European flexes had 5 cores as Brown/Black/Black (again) for three phases and d Blue for N then the fifth core was earth.
Two Blacks for two different phases! The mind boggles

I remember those flexes now you've said it.

 

[plugwash]

Not that long ago some European flexes had 5 cores as Brown/Black/Black (again) for three phases

Ah how time flies.

AIUI grey came in around 2004, as part of the negotiations to finally bring the UK fully onto the harmonised colours.

 

[SUNRAY]

So a yellow 3 pin socket should have the pins marked L1, L2, and E,

Why

and 4 pin L1, L2, L3 and E,

Are they not so marked?

and the cable will not have a blue core.

And what about when a neutral is required?

I can't think where I would use yellow cable with a blue core?

I can

Yet most yellow cable seems to have a blue core, why?

 

[SUNRAY]

Afaict a three pin red would be a perfectly legitimate way to connect a 400V single phase load,

Thinking further you are correct, that 400V single phase supply would be from a 690V 3ph supply.
More likely 380V 1ph from a 660V 3ph supply, however to clarify this: A full 3ph 660V supply would require a 4 0r 5 pole black connector.

I believe most conciencious people would use a 4p connector (or 5p without using the neutral pin {although a neutral should be run to the socket}) when feeding something with 400V 1ph using 2 of the phases from a standard 400V 3ph supply.

and a 4 pin red would be a perfectly legitimate way to connect a three phase load that did not need a neutral.

Indeed it would and I have done so on a number of ocassions.

 

[SUNRAY]

Brown, Black, green/yellow.

I've always opted for Brown, Grey, green/yellow if that is possible (rare but does happen).

Point is there is no neutral so should not be a blue wire.

What about when there is a neutral, like in the multitude of other countries who use them?

 

[plugwash]

I believe most conciencious people would use a 4p connector ..... when feeding something with 400V 1ph using 2 of the phases from a standard 400V 3ph supply.

They might well use a 4 pin or 5 pin connector for commonality with other equipment, but I can't see how there would be anything wrong with using a 3 pin. Just as it's not wrong for us to use 3 pin yellow connectors for construction site supplies.

 

[SUNRAY]

They might well use a 4 pin or 5 pin connector for commonality with other equipment, but I can't see how there would be anything wrong with using a 3 pin. Just as it's not wrong for us to use 3 pin yellow connectors for construction site supplies.

Having worked with the situation on a number of occasions, the usual expectation would be for a 4p connector if installed specifically for the service.
However I do understand your point and reasoning.

 

[ericmark]

The thread title is "Silly things" and in real life having blue instead of black is not really a problem.

As to 4 and 5 pin plugs and sockets, reducing from 5 pin to 4 pin where neutral is not required is fine. But it is when some one makes a lead 4 pin to 5 pin when it all goes wrong, and one expects a neutral which is simply not there.

The other is phase rotation, get it wrong with one lead, and it is like a disease going around the site, we had a phase rotation meter on a plug to find out where the error was. Today with inverter drives not so much a problem.

And the phase rotation meter can also catch one out, I was careful to insure new socket was correct, what I did not know, was rest of site was wrong. So it was red to red, yellow to yellow, and blue to bits.

 

[pete01]

. So it was red to red, yellow to yellow, and blue to bits

Or it just went backwards.

When I change a 3 phase board I always make sure the roller door is in the middle just incase it goes over the limits...not what you want on a Friday afternoon