what do you call the "armour" in SY cable

[SparkyTris]

does SY cable have a practical place within any interpretation of a British Standard?
what is it actually for?
why does it *always* have a transparent outer jacket?

in my own provincial orbit, the popular view is that it is Armoured Cable. I believe that it is strictly not armoured.

I understand from a brief google that the "armour"s proper name is braid.

are you supposed to connect the braid to earth?

 

[flameport]

It's a screened cable with steel screening braid.
Not armoured and not suitable for use in most of the places people use it.

 

[sparkwright]

Yes, you should earth the braiding.

Wouldn't use it outside unless covered - it seems to crack after time.

About the only place it's fit for is between the isolator and a machine in a factory or workshop.

Would also consider using high up out of reach for industrial lighting perhaps.

Otherwise, I can't imagine where else to use it.

 

[SparkyTris]

very interesting.
case in point at the moment are the deck power cables for containerised diving air-compressors and containerised hyperbaric chamber.
(in use with 5-pin 32A 400V 3-phase plus neutral site-type connectors)

would this be an appropriate cable for use in this context?

 

[mattylad]

If it's inside yes, not when it's open to sunlight as it will cause the outer to go brittle, crack and let water in.

Although there is supposed to be a version that is UV resistant.
It's still crap to work with.

Oh ISTR it is not recognized under UK standards.

 

[SparkyTris]

thanks all.
indeed this stuff is regularly used on decks of workboats so loads of oxygen, salt & sunlight. the braid seems to have a very short life as the rot gets in rapidly and you can see its rusty through the transparent jacket. I think it is transparent so that punters in a shop are suggested that it is "armoured".
Im not sure exactly what mechanical protection that braid provides, but not much I dont think. in a crush situation the inner conductors generally become exposed.
I see that RS states it is a control cable. as such - weird that it is sold in fairly high cross-ssectional areas.

why is it so popular?

I feel that this needs a Ban-All-Sheds obsessive detail response.

and are we of consensus that there is no oddball section of a guide document that says "...one way of achieving this is with the use of SY cable..."

and no British Standard applies to it?

 

[bernardgreen]

​

Product Details​

RS PRO SY Control Cable​

The SY control cables from RS PRO are number coded and are reliable connecting cables which combine the characteristics of a flexible mains cable with that of a steel wire armoured type, ideal for use in conditions where mechanical stresses are prevalent and where free movement is required. The SY type cable is often referred to as instrumentation cable, flexible or braided control cable.

These reliable steel wire braid cables work well within the machine tool industry. As interconnecting cables for measuring, controlling or regulation in control equipment for assembly and production lines, conveyors and for computer units. As well as where equipment or machinery may be subjected to vibration and or movement.

They are suitable for internal dry, damp or wet room environments, they are resistant to certain oils, acids and caustic solutions at room temperature. They may only be installed outdoors with UV-protection and by observing the temperature range.

They are made from an inner grey PVC sheath, with an outer transparent PVC sheath, the braid is galvanised steel and the cores are black with white numbers. Due to the way these cables are made and the materials used, there is a high degree of flexibility.

Features and Benefits​

· Ideal for indoor use where mechanical stresses are present
· Galvanised steel braided multi core cable, strong and durable
· SY type cable has a clear PVC transparent outer sheath
· White numbers on the outer sheath
· Inner sheath made from grey PVC
· Mechanical protection due to galvanised steel wire braid
· Flexible cable with copper conductors
· Operating temperatures for flexible use -5 to +70 °C
· Operating temperatures for fixed installation -40 to +80 °C
· Keep out of direct sunlight and observe temperature range if using outdoors

Standards​

This cable confirms to ECD 73/23/EEC (low voltage directive).

​

Type SY

Note​

SY control cables are not suitable for fixed wiring applications requiring compliance with the requirements set out in BS7671

copied from https://uk.rs-online.com/web/p/control-cable/8274215?gb=s

 

[Murdochcat]

Do not use SY …..

 

[RandomGrinch]

As here...

About the only place it's fit for is between the isolator and a machine in a factory or workshop.

Our use of it is to connect up machines in our mechanical workshops.
The flex gives a bit more resistance against swarf and oil, as well as remaining flexible - you may still need to move machines around a bit, to fit in lengthy materials.

 

[crystal ball]

Often seen on outdoor aircon units, just removed a length today, outer just about disintegrated, braid rotted away, inner sheath starting to deteriorate

 

[SUNRAY]

I tend to use SY cable where wear is likely in temporary situations and SWA would be excessive.
I'm not trying to give the impression it's a tough cable, on the contrary the outer clear sheath is fairly easily damaged, however that leaves a metal protected layer followed by another PVC layer.
It's easy to see/feel a damaged sheath, unlike HO5 or HO7 where some splits can go unfound, the braided screen offers protection against metalic puncturing into the live conductors and tripping MCB/RCD which may not be the case with HO5&7 cables. Like HO5&7 it is nearly flexible and lays flat on the floor or ground, unlike SWA.

I know others have different views/opinions but in my risk assessments, I like the added electrical protection offered rather than the mechanical protection of a much heavier and stiffer SWA.

 

[plugwash]

why is it so popular?

I suspect because it appears to combine mechanical protection and protection by earthed metal with flexibility and ease of termination. That is a combination that people are often looking for and that is not offered by any of the "normal" UK cable types.

 

[Gigagator]

Often seen on outdoor aircon units, just removed a length today, outer just about disintegrated, braid rotted away, inner sheath starting to deteriorate

Purely out of interest, what did you replace the SY with? Regular black flex or something like Arctic flex?

 

[crystal ball]

Purely out of interest, what did you replace the SY with? Regular black flex or something like Arctic flex?

HO7

 

[mattylad]

I use it often at work, I have built equipment that uses upto 11 core SY cable, we stock upto 24 core.
Used as equipment wire it's OK, when some numpty then grabs some to power an external aircon unit then problems can arise and a proper electrician then has to step in and change it to SWA

At a previous workplace we used to use it for the foot pedal wire to a big bending machine etc. Worked well until a sheet of steel was dropped onto it and then you could easily see the damage.
I have seen (and used) those SY glands with the slot in, don't bother with them any more and just use a plastic gland and take the outer core direct to an earth bar instead.