SY Cable? Thoughts?

[Deleted member 105018]

I was once told that SY has never been rated for power (ie high currents) by an NICEIC quality supervisor. We use it for input/output at 24v for devices close to the PLC on machines unless we’re using ProfiBus. Any power work is done in SWA or manufactured specific cable (Siemens basically demand you use their cable for their servo motors). I’ve also heard on the grapevine that because the braid isn’t always terminated, a damaged cable can cause it to become live. Nevertheless it’s powering my shed!!!

 

[Darkwood]

I was once told that SY has never been rated for power (ie high currents) by an NICEIC quality supervisor. We use it for input/output at 24v for devices close to the PLC on machines unless we’re using ProfiBus. Any power work is done in SWA or manufactured specific cable (Siemens basically demand you use their cable for their servo motors). I’ve also heard on the grapevine that because the braid isn’t always terminated, a damaged cable can cause it to become live. Nevertheless it’s powering my shed!!!

Question is how does the SY get from your house to the shed?

 

[MFS Electrical]

This subject has interested me. What did they change?

Just some words on the spec sheet probably I’ve never seen an SY gland made off properly anyway so it’s probably a good thing

 

[Deleted member 105018]

Haha. If I told you it was buried would you tell me off?

 

[mickfred]

Come across a light wired in SY yeasterdy . Shoved in a 13 amp plug, braid hanging out and very near to going in to the plug . Hate the stuff and should only be able to be sold with correct glands supplied

 

[Silly Sausage]

Haha. If I told you it was buried would you tell me off?

Instrument techs shouldn't be let within a 100 miles of electrical work

 

[Chris1234]

I use it in industry, a lot.
We have a £30k traveling saw, loads of SY.
£2 million extruder, SY connects rotating / travelling parts, and every induction motor on it, rough guess is around 30 of them.
I’ve never found any damaged due to oil etc.

We have maybe 200 cable drops suspended from unistrut with commando plugs on the end in SY, the specific glands make a very strong connection so the cable doesn’t get pulled out. A previous factory also had the same, never had a problem.

One thing to note is you can get overheating where a standard compression gland has been over tightened on it, I’ve seen this a few times.

 

[Darkwood]

I use it in industry, a lot.
We have a £30k traveling saw, loads of SY.
£2 million extruder, SY connects rotating / travelling parts, and every induction motor on it, rough guess is around 30 of them.
I’ve never found any damaged due to oil etc.
.

Are you saying you have SY in a constant flexing motion on a machine here or am I reading this wrong?
You are also saying you install a pvc outer sheath cable in an environment where it is subject to oil?

The difference I would suggest is a cable flexing 1000 - 10,000 times before breakdown and 10million and also a pvc degrading within 2-5 yrs or lasting 20yrs subject to and nature of the chemical oils.

Are you providing a machine that requires costly services every few yrs after warranty of a machine runs out or one that will last, trust me I know the difference just from a visual inspection.

 

[Deuce]

Are you saying you have SY in a constant flexing motion on a machine here or am I reading this wrong?

I was about to say the same thing but in Germany I was once shown around Festo's factory in Stuttgart and their assembly machines used it too.

Constant movement, nothing more than some basic cable support around the glands. I think they were using it's relative inflexibility to support itself and protecting it around the wear points at either end of the cable.

I'm going to be careful now as I was just 23 years old at the time, I may have not judged the situation correctly. However I'm also going to keep an open mind as I see a lot of SY in machine use in Germany (albeit mostly more static) and it wouldn't be the first time the British have scoffed at an idea, and pointed to all the reasons it can't be a good solution.. whilst elsewhere in the world others are using that solution with no problem whatsoever.

The supposed chemical weakness is of particular interest. Is this evidence based? Or just that on paper it could be a weakness, but in real world use it never really manifests as a problem?

 

[Darkwood]

PVC is not good against oils, it is well known and is evidenced based, there was major issues in the past with PVC and bitumen based building materials also other insulating or decorative, this somewhat led to a change in the chemical structure of pvc but it still cannot cope with natural or synthetic oils, you can easily tell because it start to become stiff as the oils leach out the natural plasticisers in the pvc.

I design controls for machines and the wiring to boot, I have to use specialised cables to suit too like used in energy track where they are designed for repeated constant movement, I spec'd some of my jobs to give a service life according to the manufacturers details of 10 to 15yrs with flexing in the million+, some of them are still going after 20yrs.

I can tell you from experience that I seen SY used to do the same and it barely makes a yr on frequent flexing and is why it is not designed for it, I can cite you all the info from companies like Lapp or Igus who make these cables and have spent 100,000's designing and proving their products ...

SY is snake oil to the electrical industry, it has been pushed and promoted by non electrically minded sales people to ignorant professionals that it is a wonder solution but like expressed before, it is not recognised by BS standards and is misused so much it is worrying for the industry as a whole.

 

[Deuce]

PVC is not good against oils, it is well known and is evidenced based, there was major issues in the past with PVC and bitumen based building materials also other insulating or decorative, this somewhat led to a change in the chemical structure of pvc but it still cannot cope with natural or synthetic oils, you can easily tell because it start to become stiff as the oils leach out the natural plasticisers in the pvc.

I design controls for machines and the wiring to boot, I have to use specialised cables to suit too like used in energy track where they are designed for repeated constant movement, I spec'd some of my jobs to give a service life according to the manufacturers details of 10 to 15yrs with flexing in the million+, some of them are still going after 20yrs.

I can tell you from experience that I seen SY used to do the same and it barely makes a yr on frequent flexing and is why it is not designed for it, I can cite you all the info from companies like Lapp or Igus who make these cables and have spent 100,000's designing and proving their products ...

SY is snake oil to the electrical industry, it has been pushed and promoted by non electrically minded sales people to ignorant professionals that it is a wonder solution but like expressed before, it is not recognised by BS standards and is misused so much it is worrying for the industry as a whole.

In such circumstances, could sy cope for 1 year without issues? In a single years use is there a concern about oils and subsequent breakdown?

 

[LeeH]

Just to add my 10p

SY (and CY) is a pretty poor cable for EMC compatibility too (VSDs) as the screening is usually extremely poor (full of holes) and it’s impossible to buy it in a concentric formation ie 3 core.

So it’s no good for anything basically but the AC boys cannot get enough of it.

 

[Darkwood]

In such circumstances, could sy cope for 1 year without issues? In a single years use is there a concern about oils and subsequent breakdown?

When you design a machine and its controls and cabling you sell it on the premise it is of good design and service is minimal and not too costly, in answer to your question then I would need to know the travel, the duty of flexing and the usage of the machine but regardless of this SY is not a cable designed for constant repeated operational flexing, I will provide a link to show you how much tech' goes into energy cables (constant flexing cables)..just an example of many companies out there I use that you don't get at you average wholesalers ...https://www.igus.com/contentData/wpck/pdf/US_en/7 guidelines for continuous flex cables.pdf

 

[Darkwood]

Just to add my 10p

SY (and CY) is a pretty poor cable for EMC compatibility too (VSDs) as the screening is usually extremely poor (full of holes) and it’s impossible to buy it in a concentric formation ie 3 core.

So it’s no good for anything basically but the AC boys cannot get enough of it.

You are correct for the most of your comment but weirdly some VSD manufactures promote and accept the use of SY cable as a solution, the issue is the quality, most SY has loose wound braiding, the ones they suggest has compact tight braiding ...easy to tell in that it is impossible to unravel the braiding on the good stuff without time and determination although the correct expensive glands should be used anyway.

 

[LeeH]

The only time I’ve seen a decent SY braid was on a project in Holland when the customer requested all cabling had to be from LAPP.

Everything I’ve seen from the normal wholesalers has more holes in it than a sieve.

I’m aware some manuals state it can be used but the fact you cannot buy it in 3 core, it’s poor steel braid makes in useless especially on large motors.

I’d rarther (and have) use SWA. But that has its own issues as you cannot terminate that directly into the drive.

 

[suffolkspark]

You can buy it in 3core?
Just a note rode wickerman at alton towers in the summer.... Theyve used it for all the speaker cabling and at thorpe park there was an abundance of it on the ride controlls of swarm

 

[netblindpaul]

The only time I’ve seen a decent SY braid was on a project in Holland when the customer requested all cabling had to be from LAPP.

Everything I’ve seen from the normal wholesalers has more holes in it than a sieve.

I’m aware some manuals state it can be used but the fact you cannot buy it in 3 core, it’s poor steel braid makes in useless especially on large motors.

I’d rarther (and have) use SWA. But that has its own issues as you cannot terminate that directly into the drive.

The thing with SWA is that it is not suitable for EMC screening that drive cables will require.
This is a known issue with SWA & drives, and has been proven with EMC testing and analysis.

 

[Midwest]

I installed SY cable in the car factory in the 1980’s. It was used on conveyor systems etc. I know the paint shop install I worked on is still there, wonder if the cable is?

 

[suffolkspark]

Played crazy golf last week and it had been used everywhere on the course which is only a few months old! Chucked in the water features and laying on gravel and all in sunlight, ill give it a couple of years! Its been used everywhere! outside lights etc all in compression glands! Bloody abortion

 

[Tes369]

Nothing wrong with the stuff at all if your mindful of its limitations like any other cable.

*I'm not agreeing with the post above.

 

[Spoon]

but the fact you cannot buy it in 3 core,

Just for your info mate. Eland do SY from 2 to 18 core.
https://www.elandcables.com/media/1677951/veriflex-sy-pvc-yslysy-control-cable.pdf

They do state in the spec:

 

[Darkwood]

I think there is some confusion here to what classifies as SY cable, SY is a standard pvc flex with an external braid and usually a clear jacket, other cables with a braid are not necessarily SY even if they appear to be, the proper energy cables fitted to most automation plants or many of the machines I service have very similar traits and sometimes appear to be SY but they are specialist cables that you cannot just walk into your wholesalers and pick up off the shelf.
When I buy the correct cabling for repeated flexing joints you are required to do a lengthy check list of all the environmental issues it may be subject to, the bending radii, the number of flexing actions it will undergo etc etc and you are looking at several quid a meter in comparison to a quid a meter for its equivalent SY version, the last stuff I used was from IGUS and came in at about £400+ for 2 x 15m lengths of chainflex cable 4mm 4core and a 15m 7core which is about 5 x the cost of equivalent standard SY and understandably so, it has a 10million flex lifespan and on the job I put it on it will last 10yrs plus (exposed to all outdoor temperatures, direct sunlight etc), If I used normal SY it would fail within a few yrs and end up costing more in replacement and servicing over the same period.

I did have pictures of when standard SY is used in forced flexing conditions and the results are not pretty but cannot find them, I will also put my hands up to its deliberate use myself but only as a stopgap to get a machine running while the correct cable is been shipped in.

If one understands the construction of a energy flex cable and why it is design like that and compare it to your bog standard SY then you will understand why standard SY should never be used, if you see examples in the industry of what appears to be starndard SY used in this nature then I would need to know the manufacturer and the product code to give a suitable response.

 

[LeeH]

Just for your info mate. Eland do SY from 2 to 18 core.
https://www.elandcables.com/media/1677951/veriflex-sy-pvc-yslysy-control-cable.pdf

They do state in the spec:
View attachment 45625

That has a CPC in the 3 cores spoon. You should not sleeve the CPC and use it for a phase obviously.

 

[Spoon]

That has a CPC in the 3 cores spoon. You should not sleeve the CPC and use it for a phase obviously.

Obviously..
I have never done that.

 

[sparksfly]

Funny...I had to dig out/remove SY cables in a garden previously owned by an electrician...it had part turned black over time and braid was rusty ..not fit for the outdoor life.

 

[Deuce]

Funny...I had to dig out/remove SY cables in a garden previously owned by an electrician...it had part turned black over time and braid was rusty ..not fit for the outdoor life.

Maybe he took them from another place where they were not suitable and used them at home as they will do the job, and were free

 

[The_apprentice2.0]

I certainly wouldn't recommend it for external installations as I spent a chunk of last year replacing SY .... where it appeared to be UV damaged and outer sheath very brittle and cracked..... not sure on the brand as we did not complete the initial install

 

[DefyG]

A client has just purchased a portable heater (Ive not seen yet, only a photo) that was supplied with SY cable.
It was bought from a reputable British company so presumably meets BS!
The trouble is the lead is not quite long enough so have bought a marginally longer cable to replace it with.
I don't have a problem in using SY in this instance but am waiting to see how the manufacturers have earthed the braid. (Industrial 3ph [Commando] style plug to appliance).

 

[BruvDunk]

Used it all the time in the food industry a few years ago. Never had any issues.
Only issues was water ingress into the braid if the clear plastic outer got damaged from wear and tear....

Never used it on site apart from the plant room type scenarios..

 

[davesparks]

Never had any issues.
Only issues was water ingress
.

Surely these two statements are mutually exclusive?
How can you say there were never any issues then immediate after that describe an issue?

 

[BruvDunk]

Surely these two statements are mutually exclusive?
How can you say there were never any issues then immediate after that describe an issue?

Most systems will give you issues if damage has occurred!!

 

[davesparks]

Most systems will give you issues if damage has occurred!!

In most cases damage occurs as a result of poor design or inadequate protection. And the what happens after damage has occurred is also important.

 

[BruvDunk]

In most cases damage occurs as a result of poor design or inadequate protection. And the what happens after damage has occurred is also important.

Not really sure where your heading with this, SY has a place along with all other cables, methods etc

You select, design accordingly !

 

[cliffed]

It’s being used everywhere,young lads are using it for temp electrics on site,supplies to caravans.
We would never use it always Swa’s..it’s not a BS & discouraged for use in 18th,use it at your own risk assessment & peril

 

[davesparks]

Not really sure where your heading with this, SY has a place along with all other cables, methods etc

You select, design accordingly !

I'm not heading anywhere, just sharing my views on the subject.
Yes it has a place, and when it is the best cable for a particular job I will use it. However it is very often used when it is not the most suitable cable for the job, or where it is unsuitable fir the job.

 

[cliffed]

Seen so much of it used,it’s easy to install,I personally don’t like it.
It’s something that’s happened over the years,all because of fast fix,cost issues I presume.
In my day it was either Swa,trunking,conduit,flexible conduits,the skill of sparkies slowly being put to the bottom of the ladder.

 

[Chris1234]

Are you saying you have SY in a constant flexing motion on a machine here or am I reading this wrong?
You are also saying you install a pvc outer sheath cable in an environment where it is subject to oil?

The difference I would suggest is a cable flexing 1000 - 10,000 times before breakdown and 10million and also a pvc degrading within 2-5 yrs or lasting 20yrs subject to and nature of the chemical oils.

Are you providing a machine that requires costly services every few yrs after warranty of a machine runs out or one that will last, trust me I know the difference just from a visual inspection.

Yes, to the first part, your right it does get damaged tbefore other cables.
All the machines mentioned have been bought with SY, we haven’t put it in, only replaced like for like.
The rotating part I mentioned was the rotating platform contain the nip rollers way above a fiom extrusion machine. The platform rotates slightly more than 360 degrees, but due to some clever mechanical linkages, the cable only travels 180 degrees. The atmosphere up there is very hot and greasy from the plastic.

 

[Chris1234]

I run it in Unistrut quite a lot. No particular reason!

I think for mechanical strength it can’t be beaten.
The way it attaches to its special glands makes it very strong. I use it for power leads on portable machinery, people tend to try and more machines with unplugging them, which of course would pull cab.emour of a normal gland.

Do you happen to know how much the orange (or is it green?) Rexroth Indramat cable is?