2.5mm wire into 1.5mm plug

[Martiv]

I’m welding and have a cable blue 2.5mm 3 core 10metwrs to reach my shed

the plug and socket I got to wire on them biggest hardware has says 13amp but then says 1.0-1.5mm wire rated
online said I can stil do it but it’s a squeeze is that acceptable ?

I use 2.5 for it stops volt drops while welding you can see it in the end weld teated it from wall on my extension and on friends 2.5mm and yeah wall and his cable weld the same my old 1.5extension has a drop you wouldn’t know until you compare welds

so I got the blue cable but can’t find plugs n socket that say 2.5mm in hardware store do I wire the ones I got by master plug a 2 socket and a plug 13amp heavy duty

 

[loz2754]

BS1363 13 amp plugs are designed to accept a maximum of 1.5mm² cable.

 

[James]

ABB 16A 2P+E Connector 250V - Screwfix

Order online at Screwfix.com. 2P+E. 250V. 16A Compact design, excellent grip industrial plug. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

for 2.5mm cable you need to upgrade your plug and socket to something like this.

 

[Electro-tech]

As James posted. It would seem that upgrading to a 2.5mm cable reduces volt drop, but the 13amp connections at either end may warm up with long periods of welding even if you manage to wire them. What is the max load of the welder?

 

[Martiv]

As James posted. It would seem that upgrading to a 2.5mm cable reduces volt drop, but the 13amp connections at either end may warm up with long periods of welding even if you manage to wire them. What is the max load of the welder?

It’s only a 210 arc I weld at 90 to 150 amp max
not really for long times either i tinker as I need to make a tool etc

was told it’s a squeeze but that they wire it into a 13amp plug and socket still ?

I can’t plug that in me bloody wall or welder haha not sure what a 16amp is thaight max I can run is 13amp plugs without getting them yellow boxes

 

[timhoward]

I can’t plug that in me bloody wall or welder haha not sure what a 16amp is thaight max I can run is 13amp plugs without getting them yellow boxes

The yellow boxes do a different job - they are for connecting 110v gear.
It’s not usually complicated to get an appropriate socket installed with appropriate protection for the supply. The easiest way to do it depends on lots of unique local factors so you really need some advice from someone standing in front of it all.

 

[davesparks]

Have you checked your existing 1.5mm extension lead for any damage or loose connections at either end? Is it in good condition, are the pins of the plug clean and shiny or are they tarnished?

And have you confirmed it is in fact 1.5mm? A lot of 13A extensions are made with 1.0 or 1.25 flex.

 

[Avo Mk8]

BS1363 13 amp plugs are designed to accept a maximum of 1.5mm² cable.

I see a lot of discussion, dare I say argument, on forums about this point (eg IET)
Is someone out there in the 13A plug manufacturing business?

From BS 1363-1:1995 and A4:2012, (which might be out-of-date?) "Provision shall be made for the entry and effective clamping without bending of 2-core and 3-core flexible cords for rewirable plugs as given in Table 11, Table 12, Table 13, Table 26 and Table 27 of BS 6500:2000, having nominal conductor cross-sectional areas not exceeding 1.5 mm2."

The standard does not give a maximum size of cable csa that can be used, it effectively sets the minimum size for the termination, ie a 1.5mm csa cable MUST fit.
Limitation comes from manufacturers who rightly specify maximum cable size for their product. That doesn't stop other manufacturers making plugs that do accept 2.5mm cable.

And I believe all this is for rewirable plugs, not permanently affixed (eg moulded) ones

I see several ready made 10m or more extension leads on the market, from seemingly reputable suppliers, available with 2.5mm flex with a 13A plug one end and a single 13A soclet on the other, eg:

14M Extension Lead 240V 13A Heavy Duty 2.5mm Cable

www.orbitalfasteners.co.uk

If the OP needs to keep voltage drop to a minimum, but the average power requirement is within the rating of a 13A plug/socket combo and the house circuit, I don't see a problem with the principle of buying a commercially available, properly tested, 13A extension lead incorporating a 2.5mm flex.

 

[loz2754]

Limitation comes from manufacturers who rightly specify maximum cable size for their product. That doesn't stop other manufacturers making plugs that do accept 2.5mm cable.

And I believe all this is for rewirable plugs, not permanently affixed (eg moulded) ones

An interesting point.

However, if a manufacturer chose to make 13 amp rewireable plugs that accommodate 2.5mm² cable, they would not to be able to claim compliance with BS1363, at least that's the way I see it.

I wonder what the specification says about non rewireable plugs...(if anything).

 

[Julie.]

An interesting point.

However, if a manufacturer chose to make 13 amp rewireable plugs that accommodate 2.5mm² cable, they would not to be able to claim compliance with BS1363, at least that's the way I see it.

I wonder what the specification says about non rewireable plugs...(if anything).

It would come down to the detail in the wording of bs1363, and bs6500.

However specifications usually detail the minimum size of the maximum capacity, in other words "take cables up to a minimum of 1.5mm^2" so anything from 0 to 1.5mm^2 must fit, it usually doesn't preclude 0 to 1.6mm^2 or 1.7......etc.

It would be difficult to do otherwise, after all if you used a cable of 7 strands to get 1.5mm^2 it would have a larger diameter than 64 smaller strands also of 1.5mm^2.

So if you made it of the correct size to just take the 64 strand cable, it wouldn't take the 7 strand cable - so definitely wouldn't be compliant, conversely if it was large enough to accept the 7 strand version, it would be able to take larger cross section multi strand cable.

Unfortunately specifications aren't often clear with just extracts, the detail is important, bs1363 is likely to reference the size/type of cable in bs 6500 using the terminology in bs6500.

Thus bs 6500 may detail cable dimensions via definitions of cable sizes as "dimensions of cables for"
"Not exceeding 0.75mm^2".....
"Not exceeding 1.0mm^2".....
"Not exceeding 1.5mm^2".....
"Not exceeding 2.5mm^2".....
And so on.

Then bs 1363 sets the minimum size of hole to that which fits the dimensions of the 1.5mm^2 cable, which by name is "Not exceeding 1.5mm^2"

Hence it may look like 1.5mm^2 is the maximum, but it is actually just the minimum size of hole required.

Unfortunately to determine exactly, the actual standards must be examined in detail.

 

[telectrix]

jfyou can't get it in with a hammer, phone an electrician.

 

[ElectricBanana]

I have known 2.5mm to be squeezed into a permaplug but it isn't ideal.

Better option - put a 16A plug on your welder, and turn your 2.5mm extension lead into a 16A extension lead by putting a 16A plug and socket on each end.

Then make up a short adapter lead from 1.5mm with a 16A socket and a 13A plug or buy one ready made (i.e. something like this Fly Lead Socket Convertor 13A Lead to 16A Socket | Toolstation - https://www.toolstation.com/fly-lead-socket-convertor/p47166 )

That way you can plug your welder in to a 16A supply if it is available, or a 13A socket if you are welding at low currents.

If you are going to be doing a lot of welding, it would be worth investing in having a 16A socket installed, even for the robustness if nothing else.