# 4 pole socket for boiler ?

That's not the hard part - it's having someone understand that a 4 or 5 pin socket isn't 3 phase.
Which is surely the point of the colour system and not using a Red socket with single phase, the Red 3 pin you quoted was for 2 phase and E, so i guess not likely for the UK market, a red socket denotes too most people that at least 2 or 3 phase may be present and the voltage may be higher than normally expected from a Normal blue outlet.
Similar to why you see Yellow on building sites, this is drummed into any engineer or trade thats taken his Ecs Health and safety course.

According to the table on Wikipedia, the red 3 pin is in a column labelled "P+N+E, 2P+E" so could be Line+Neutral or two Lines, and the heading specifically says that P is Pole and not Phase - but either way there's up to 415V between pins. I agree it's not likely to be found over here - more likely to find 4 or 5 pin sockets and if a device did need a single phase @ 415V then it would just have one phase and neutral pin unused in the plug.
For a blue socket, it's 200-250V P-N for a 3 pin but only 120-144V P-N for a 5 pin plug. Thus it would not be correct to have a 5 pin blue socket with 240V P-N.

Looking at the way the table is done, it looks very much like the colour code is the highest pin-pin voltage present.
While I can see your argument that this would not have more than 240V between any 2 pins, it would (in theory, but rather unlikely) for someone to plug something in expecting no more than 144V P-N which would then let the magic smoke out. Safer to use a red socket - that way nothing could get plugged in that wasn't designed to take 240V P-N. it would be "wrong" in that it didn't have 3 phases or 415V - but nothing would be "right" for this application.

the heading specifically says that P is Pole and not Phase
In that case aren't "P+N+E" & "2P+E" the same?

While I can see your argument that this would not have more than 240V between any 2 pins, it would (in theory, but rather unlikely) for someone to plug something in expecting no more than 144V P-N which would then let the magic smoke out.
F*S Simon, this is a CH installation in a church hall, not an electrical provision in an open-to-all, "run what yer brung" industrial complex.

In that case aren't "P+N+E" & "2P+E" the same?
Yes, AFAICS
F*S Simon, this is a CH installation in a church hall, not an electrical provision in an open-to-all, "run what yer brung" industrial complex.
So ? Is that an excuse not to do things properly ?

Of course it isn't.

But it has a bearing on what constitutes "properly".

So you advocate installing a socket :
• whose specification restricts phase-neutral voltage to 144V (and therefore any equipment fitted with a matching plug could be assumed to work on such a low voltage)
• in a circuit where the phase-neutral voltage is 240V (and therefore could be assumed to be in excess of what such equipment is designed to tolerate)
• and there is an equivalent socket available whose specification allows for 240V phase-neutral ?
If anyone else had proposed that, what would your likely response be ?

So you advocate installing a socket :
• whose specification restricts phase-neutral voltage to 144V
No.

Hence the rest of your questions are defunct.

Then you really need to address your approach so you don't come across as doing so.
It is clear from your statements (taken in total) that you consider it "OTT" to suggest that using a red socket is more correct (or less incorrect) than a blue one - and justify this by inferring that it's irrelevant since it won't happen (someone plugging in the wrong bit of kit), see your post 19. You then go on to say that the situation does affect what is considered to be "properly" in your post 21, after all, if it has an effect on what constitutes "properly" then the inference is that you consider using a blue socket as OK in some situations.

So either "properly" means using a socket of appropriate voltage ratings all the time, in which case your earlier posts are "incorrect" - or it means using a socket of inappropriate ratings is considered "proper" in which case your answer of "no" is false.

And given that one of the people in charge of the building blew a fuse (15A rewirable) by plugging in several fan heaters - "but was careful to plug them into different sockets" so "I don't know why it didn't work". He then went on to be amazed that I could find the blown fuse - he thought nothing was blown because all the MCBs (plug in MCBs in an old Wylex board) which only fed the lights were all on.
So yes, things have to be made idiot proof - so it's simply not possible to plug something in (even if it's highly unlikely they'd find such a thing) that could be damaged by inappropriate voltages.

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So either "properly" means using a socket of appropriate voltage ratings all the time, in which case your earlier posts are "incorrect" - or it means using a socket of inappropriate ratings is considered "proper" in which case your answer of "no" is false.
"Appropriate voltage rating" means connectors rated for at least the highest voltage present.

Your concern seems to be that if you use red accessories that this would be inappropriate because the voltage between the pins would be too low.

And given that one of the people in charge of the building blew a fuse (15A rewirable) by plugging in several fan heaters - "but was careful to plug them into different sockets" so "I don't know why it didn't work". He then went on to be amazed that I could find the blown fuse - he thought nothing was blown because all the MCBs (plug in MCBs in an old Wylex board) which only fed the lights were all on.
So yes, things have to be made idiot proof - so it's simply not possible to plug something in (even if it's highly unlikely they'd find such a thing) that could be damaged by inappropriate voltages.
What did your risk assessment conclude about the possibility of the people in charge of the building deciding to bring items of 3-phase equipment into the building because they thought they could now run them there, and unplugging boilers, valves, controllers, whatever in order to plug them in?

a red socket denotes too most people that at least 2 or 3 phase may be present and the voltage may be higher than normally expected from a Normal blue outlet.
Hands up all those who think that the fan-heater person described by Simon would be one of those people.

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Hands up all those who think that the fan-heater person described by Simon would be one of those people.
Actually, I don't think he'd know what the plug was !

Your concern seems to be that if you use red accessories that this would be inappropriate because the voltage between the pins would be too low.
Then you haven't comprehended much of the discussion at all have you - because that is NOT the concern
If you look at the table on the connectors specs/coding, you will see that the maximum phase-neutral voltage for a 5 pin blue plug/socket is 144V and phase-phase maximum is 250V. For a red connector these figures are 240V and 415V.
So, lets say we go with your argument that there will not be more than 240V present if we use a blue socket. Should someone find a bit of equipment with a matching plug, what's it's specs likely to be ? Phase-phase will be "safe" because there won't be any voltage between phases. But phase-neutral will be 240V for something that might be specced for only 144V - oops It is true that the chances of someone finding such a piece of equipment are slim - but they do exist and I've worked in environments with a 240V phase-phase voltage (in the UK and abroad).
But using a red socket, again there will be no phase-phase voltage - but the 240V phase-neutral will now be within the spec of 200-240V. Even though equipment with such a connector is more likely to be found, it shouldn't be damaged because it won't be exposed to a voltage above what it's designed for, and most likely "nothing will happen, it just doesn't work".
But to be honest I'd not be too worried either way - because as you say, it's not like it's some industrial complex with loads of 3 phase hand tools around.

I hadn't intended a long discussion on the merits of red and blue, I was only asking if anyone had ideas for connectors. I'm still thinking Klix 4 pin might be more appropriate

I hadn't intended a long discussion on the merits of red and blue, I was only asking if anyone had ideas for connectors. I'm still thinking Klix 4 pin might be more appropriate
I'm thinking Klix 4 pin might be more appropriate as was mentioned right at the start.
As long as you don't employ a professional electrician who will insist they are exclusively for lighting systems and the 'E' pin is for the power to the emergency part of the fitting.

CEEforms are ridiculously over spec'd for the application although perfectly acceptable. As to the concerns about incorrect application of these connectors. I say use them properly as I have come across so many silly applications, some of which are potentially dangerous:
1P power to a van using a red 3PNE, L2 & L3 had a short in the socket, in the van was a relay to inhibit the starter solenoid:

with the van was a cable with a blue plug and red socket which worked successfully for several years. On a site the temp electric supplier had been asked to provide a 16A supply and seeing a red plug applied 3ph.

I've seen 32/3 being used as 2x1ph (2xL & 2xN with common earth).
Both of the above did a lot of damage.

I've previously posted a couple of times with pics of a welder supply and on a building site.

Using a 16/3 for a boiler 'shouldn't' cause any problem if someone tried to use the socket to supply a3ph device but applying 3ph to the boiler plug would very likely damage the pcb. Klix is a much better option but do you not require 5 poles? LNE supply, demand & pump.

If you look at the table on the connectors specs/coding, you will see that the maximum phase-neutral voltage for a 5 pin blue plug/socket is 144V and phase-phase maximum is 250V. For a red connector these figures are 240V and 415V.
So use a red one then.

"Maximum" is not the same as "mandatory".

So, lets say we go with your argument that there will not be more than 240V present if we use a blue socket. Should someone find a bit of equipment with a matching plug, what's it's specs likely to be ?
And just who are "they"? And where will "they" find this equipment and decide to bring it into the church hall to plug it in?

Phase-phase will be "safe" because there won't be any voltage between phases. But phase-neutral will be 240V for something that might be specced for only 144V - oops It is true that the chances of someone finding such a piece of equipment are slim - but they do exist and I've worked in environments with a 240V phase-phase voltage (in the UK and abroad).
F*S this is a church hall.

Just who is going to be finding anything and deciding to take it to the hall, to unplug part of the CH system, and plug what they have found in?

Even though equipment with such a connector is more likely to be found
Found by whom? And where?

Just who are these people who are going to find this sort of equipment? And where will they find it? And why, having found it, will they take it to the hall to plug it in in place of part of the CH system?

But to be honest I'd not be too worried either way - because as you say, it's not like it's some industrial complex with loads of 3 phase hand tools around.
Precisely.

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