Bootlace ferriles

[Sparkattack]

Came acroos this today during an inspection of a 3 phase square D load centre. The cable was a temporary supply to some contractors cabins onsite, 32 amp MCB which was terminated with a bootlace ferrile. I know bootlace ferriles are widely used in control wiring, im just interested in peoples opinions on there use for this application??

 

[Sparkattack]

Yeah how did you guess, this must be a common requirement in the industry! Youve got a point its only as good as the person installing it i suppose!

 

[Marvo]

For general house circuit or RFC wiring it seems to be a swings and roundabouts thing to me.

On the pro side it may result in a mechanically stronger connection and a lower resistance connection but I've scoured the net for conclusive data from studies of this and I can't find any.

On the con side it's time consuming, it needs probably more than one good quality crimper tools, a range of several sizes and combinations of ferrules and it makes for difficult splitting up of a circuit for future testing.

If you add that to the lack of any requirements for this procedure in the existing (or previous versions) of any regulations I've ever seen, I won't be adopting the method as standard practice at least for now.

If I can see some real evidence of the benefits of using this method and the need for those benefits then I would happily review.

 

[johnboy6083]

i wouldnt use this method for anything other than flex connections, and process systems , ie pumps/machines ect, and the control sytems for these.

for normal building services, i dont bother, as the terminals on most of the gear is tight as it is, never mind adding bootlace ferrules.

 

[johnboy6083]

Yeah how did you guess, this must be a common requirement in the industry! Youve got a point its only as good as the person installing it i suppose!

your profile mate.

 

[Engineer54]

I agree with some of your points spin. Crimpers are expensive, my self adjusting one cost me £113. I also agree that using double bootlaces ferrules is a pain when it comes to testing or fault finding. That's when I prefer to use spades.

I don't agree with the conductor deforming argument. I see far more deformation from twisting normal stranded cable. I do agree that there is no need to crimp these cables, but i don't see a detrimental effect of doing it. Also I disagree with the poor conductivity argument. You get no less surface area contact on a ferrule, than you would on a solid core.

Deforming of the conductor within the terminal crimp, is the main point of a good crimping tool, especially the non insulated crimps. Apart from anything else, it secures the crimp to the conductor.

No-ones saying that crimped terminals should always be used, but on all of the high standard prestige projects, you will normally find that the contract specifications will most certainly call for there use on all final circuit distribution boards and panels etc!!

As for contact area, that very much depends on the type of crimp connector, or ferrule your using, along with the shape of the crimping tool dye. With the flat pin crimps you will certainly have far more contact area than that of a solid core conductor.

 

[vaughant]

As E54 says their near enough standard in industry,particularly in the control side of things.
A good crimp tool helps but I'm personally not a fan of any of these ferrule things on anything above 10mm cable,I've seen a few burnouts recently on IR heater plugs and each time the cause has been these things,quite possibly not connected right in the first place but IMO every termination or join in cable is just another place where a fault could occurr(that's the control spark in me coming out).
I cured the heater problem by squashing the ends in the terminal post and tinning the ends with solder and I've had no failiures since.
Obviously this is even more bloody time consuming!!!

 

[Adam W]

Marine wiring uses stranded cable to allow for vibration, so all terminations are made either with a ferrule or in clamp type terminals or wagos, but never a screw termination such as in a plugtop.

Bearing in mind the way a ferrule works (a terminal screw clamps down onto it) I don't see that a ratchet crimper would be strictly necessary; you can pick up a pair of non ratchet 'plier type' crimpers for around 12 quid.

IMO reg 526.8 requires multiwire, fine wire and very fine wire conductors to be ferruled when used with a screw terminal, as I've mentioned in other threads.

IMO there is no point using ferrules with T&E.

 

[Engineer54]

Marine wiring uses stranded cable to allow for vibration, so all terminations are made either with a ferrule or in clamp type terminals or wagos, but never a screw termination such as in a plugtop.

Bearing in mind the way a ferrule works (a terminal screw clamps down onto it) I don't see that a ratchet crimper would be strictly necessary; you can pick up a pair of non ratchet 'plier type' crimpers for around 12 quid.

IMO reg 526.8 requires multiwire, fine wire and very fine wire conductors to be ferruled when used with a screw terminal, as I've mentioned in other threads.

IMO there is no point using ferrules with T&E.

I would have to disagree with you on that one, To obtain a rock solid connection between ferrule and cable you need a ratchet crimping tool every time. To be honest, i wouldn't give a thank you for a non ratchet crimping tool, not unless your built like king kong!! lol!!

Agree with you on the T&E though, ferrules on the whole are pretty useless on solid conductors... They would require a standard flat style crimp terminal...

 

[vaughant]

Yeah the ratchet crimpers are ACE!!!
on thin cable you could probably get away with a good strong grip on the ferrule but it's just as easy with the ratchet.
Never seen them on t&e personally,pretty pointless really as it's just single core,no chances of strands hanging off.

 

[Deleted member 26818]

Reg. 526.8 as far as I'm aware requires the conductor to be protected.
This can be achieved, simply by twisting and folding over the conductor.