Fire cable (pf200) used for mains.

[Craig Pickersgill]

Hi all, this is just a question to put my mind at rest and to see if I'm right. I'm not a qualified spark and I'm not the person(s) involved with the work.... OK here we go!

My workplace (large Plc) are having the staff toilets done up a bit. A hand dryer was removed from the wall and chase made for the cable that was in a conduit.

Got to work one morning (contractor working nights.) Wall had been clad over, out of the hole where dryer to be fitted a nice loop of what I'd call pyro!! (We are also having the fire alarm worked on.) obviously I immediately know the alarm won't be going there!
So why use an off cut of this to hard wire in the hand dryer?
I think the red cable is PF200? Its made up of red outer jacket, metal clad then 2x 1.5mm in a Rubery low smoke jacket and a steel earth or PC.

So is that right? I'd say no, and it should be PVC twin and earth 2.5mm.

Our fire cable runs out of a fused spur with a 13amp fuse fitted.

Photos included and any views greatly appreciated. Thank you all.

 

[Craig Pickersgill]

Personally I wouldn't be happy with red FP200 being used for non-fire alarm installations. The colour red is specifically to designate it as fire alarm. I would much rather it be any other colour. (That said, there are other cable types, e.g. 6491B LSF singles in containment.)

A galvanised saddle might have been better than a PVC one too in order to protect against premature collapse of wiring systems in the event of a fire.

That's more like my thinking. Tbh I don't know why they chased and buried one cable but left the other in a conduit down to the FCU?? (apart from its easy )

 

[pc1966]

The other white cables look like the non-fire version of similar construction, one well-known brand is Flexishield, but generically it is to BS 8436 (UK standard) and IS 273 (Republic of Ireland standard).

They have some good features, such as the aluminium foil layer that is designed to short out the supply if penetrated by a nail, etc, and so safely disconnect power and save the poor sod with the hammer from shock even for circuits without RCD protection. They are also a bit more rodent-proof than T&E cable, but Flexishield make a special cat urine flavoured version for that job if it is a big factor:

Flexishield R for protection against rodents

Flexishield R Cable with Rodent Protection

www.flexcables.co.uk

Traditionally alarms were in MICC (mineral insulated copper clad), later with a red or orange sheath for easier identification and to reduce corrosion damage under certain conditions. However, MICC is expensive (all that copper sheath!) and tricky & expensive to properly terminate so around a couple of decades ago the liked of FP cable was introduced that has enough fire survival for the job, has the foil shield safety aspect, and is much cheaper and easier to use than MICC.

Still way more expensive than T&E though!

 

[Timbo]

a couple of decades ago the liked of FP cable was introduced

I was using FP200 in the eighties.

 

[pc1966]

I was using FP200 in the eighties.

Ah, I seem to have missed a decade or two. Damn, how does that happen!?

 

[UNG]

I was using FP200 in the eighties.

I hated it then and I still hate it now, nowhere near as reliable as MICC and FP is very rarely installed properly
I remember having to find a fault on a fire alarm system around 1987 the alarm had been install a few years earlier and had started showing an earth fault that I eventually tracked down to a crushed FP cable

Traditionally alarms were in MICC (mineral insulated copper clad), later with a red or orange sheath for easier identification and to reduce corrosion damage under certain conditions. However, MICC is expensive (all that copper sheath!) and tricky & expensive to properly terminate so around a couple of decades ago the liked of FP cable was introduced that has enough fire survival for the job, has the foil shield safety aspect, and is much cheaper and easier to use than MICC.

Still way more expensive than T&E though!

It's only tricky if you never mastered it, personally I always enjoyed a big Pyro job on the smaller stuff I could do up to 8 terms an hour not quite as quick as one of my mum's friends who worked at BICC who was doing around 20 ends an hour on piece work that paid 3d per end

 

[pc1966]

It's only tricky if you never mastered it, personally I always enjoyed a big Pyro job on the smaller stuff I could do up to 8 terms an hour

Alas, time is money on most jobs and skilled sparks like yourself are harder to come by. At least, cheaply...

I think pyro is brilliant stuff, most installations will outlive the building's use. In fact, I expect 100 year post-nuclear-apocalypse there would still be MICC circuits that would pass an inspection!

 

[7029 dave]

I did a pyro job in an office block 39 years ago, new build did all the staircase lighting and fire alarm system.
That was in Barnet London, when I visit my mother (in Barnet) I still pass the block, when the lights are burning on the staircase I chuckle an think I did that still going strong. lol