Is 1.5mm Low Smoke 3 core Flex thinner than the standard stuff?

Cinquestelle

My local electrical shop was out of stock of 1.5mm 3 core flex but offered to sell me the normally more expensive low smoke or heat resistant alternative for the same price. I have bought some but I notice that it is a lot a thinner, more like 1.00mm flex at around 6.5-7mm in diameter. Even the seller was a bit surprised however his colleague persuaded him it was normal.

My initial thought was that the lighter thinner qualities of the flex might be a characteristic of low smoke or heat resistant varieties but I'm not so sure now. I can't see 1.5 mm cable as thin as this anywhere online. The flex has the following markings on it:

318 3B1,5 LS:OH/LS:OH 300/500 V CE

Any reassurance or otherwise really appreciated.

fluffpot

If it's on a 6A breaker or smaller fuse then it doesn't make any difference - unless perhaps it's running though lots of insulation
The figure 1,5 in the above jumble of numbers appears to indicate the size perhaps??
Its the size of the copper that is 1.5mm sq not the sheathing or conductor insulation, so it might just be a bit thinner - it does seem to vary between manufacturers

Cinquestelle

Thank you fluffpot. I also think the 1,5 is the reference to size, and I understand its the size of the copper and not the sheath but I have to say I have never seen 1.5 sheath like this. Its more like 1.00. I'm using it to rewire an extension socket that needs to be a little longer. Good to know you find it variable between manufacturers. I may take it up with BASEC tomorrow.

har0ld

I know it sounds like ----! however we lower mortals should be paying for a qualified part P, 17th edition electrician to do anything like this or render our house insurance void!!!

Cinquestelle

har0ld wrote: »

I know it sounds like ----! however we lower mortals should be paying for a qualified part P, 17th edition electrician to do anything like this or render our house insurance void!!!

Attaching a longer flex to an extension socket a job for electricians? You must have been in the lobbying group that succeeded in persuading the Government in making changing a pull-cord light switch a notifiable job costing £60 upwards.

Owain_Moneysaver

Cinquestelle wrote: »

Attaching a longer flex to an extension socket a job for electricians? You must have been in the lobbying group that succeeded in persuading the Government in making changing a pull-cord light switch a notifiable job costing £60 upwards.

Changing a pull-cord light switch is not a notifiable job, regardless of in which room it is.

Cinquestelle

Perhaps a 'small' exaggeration but I am not going to employ an electrician to wire an extension socket any more than I would employ an electrician to wire a plug!

Myser

Was the cable that is being replaced suitable for appliances up to 10A or 13A?

Cinquestelle

Myser wrote: »

Was the cable that is being replaced suitable for appliances up to 10A or 13A?

If so, you may want to label the extension to state that it's now only suitable up to 6A and fit an appropriate fuse in the plug. This is to warn someone else who may use it in the future e.g. builders/tradesmen.

Do you suspect this is 0.75mm flex?

Myser

Cinquestelle wrote: »

Do you suspect this is 0.75mm flex?

Sorry for the confusion. 1.5mm should be fine up to 13A if wiring to a standard UK plug!

I have amended my previous post.

Cinquestelle

Myser wrote: »

Was the cable that is being replaced suitable for appliances up to 10A or 13A?

That's right and I want it to stay that way. I do tend to over think these things but it was the degree of surprise on an experienced seller's face that planted the seeds of doubt in the first place!