SY Cable

[Steven Haynes]

We have a production facility that is completely wired in SY cable. We have just had it tested and been told that it needs rewiring to be passed off as SY is not to be used to provide power. The reason stated being, it does not have a BS number.

1. If this is true, why is it acceptable to use it from the isolator to the motor?
2. When did this become the case? And must we rewire the entire system?
3. Can this not be noted as a departure?

 

[Spoon]

Have a look at the manufacturer of the SY cable and see what's it's suitable for.
A few years-a-go some manufacturers used to put "not suitable for fixed wiring" in the description of there SY cables.
What exactly has been wired up in SY. Is it in trunking, buried, surface mounted,....

1. It's usually used on motors to reduce interference.
2. Have a look at the manufacturers data sheet and see what it's suitable for. See below as an example from Eland
3. Depends on data sheet.

 

[bglproserve]

The end of 2018 sees the formal transition to the 18th Edition of the Wiring Regulations. A deliberate decision not to fully comply with the requirements of the Wiring Regulations, such as in the use of control cables in fixed installation, must be noted as a departure. Any use of a custom, non-standard, or partially compliant cable must be declared and assessed, and it must be ensured that the degree of safety is not compromised.

Some manufacturers claim that YY, SY and CY cables comply with the general requirements of the BS EN 50525 series, but these designs differ from the requirements of the mentioned standards. For example:

BS EN 50525 Series

BS EN 50525-2-11 is the British Standard for PVC flexible cables, but it has no provision in for any braid, therefore braided cable, such as SY cable, cannot conform to this standard. In 2017, it was reported that the insulation and sheath thicknesses of cables designated YY, SY and CY often have lower insulation and sheath thicknesses in comparison with the BS EN flexible cables. Therefore BS EN 50525-2-11is not an appropriate standard for YY, SY and CY cables.

 

[Andy™]

We have a production facility that is completely wired in SY cable. We have just had it tested and been told that it needs rewiring to be passed off as SY is not to be used to provide power. The reason stated being, it does not have a BS number.

1. If this is true, why is it acceptable to use it from the isolator to the motor?
2. When did this become the case? And must we rewire the entire system?
3. Can this not be noted as a departure?

1 motor control is usually 60204-1, not BS7671
2 its never had a BS number and never has complied, just some people love the stuff (expecially air con 'installers') and sling it in everywhere with no regard to how suitable (or not) it is
3 yes but you'd need to justify it. given the issues it with it, it would be hard to say how it just as good as complying. and chances are none of the ends are terminated correctly into CXT glands...

id be going back to whoever wired it incorrectly in the first place

 

[Sidewinder]

Remember where BS7671 ends.
Outside the scope of BS7671 then SY, CY & YY can be used.
Personally if the SY is good quality and correctly installed and terminated then I don't have a massive issue with it being used for the fixed installation.
I have used it to overcome specific external influences.

 

[James Page]

Standards are not compulsory (see 511.2, and any general inf on standards law)
I would see what evidence of safety your cable manufacurer has

 

[Sidewinder]

Standards are not compulsory (see 511.2, and any general inf on standards law)

That's correct, but legislation often relies on standards to achieve compliance.

 

[unphased]

Remember where BS7671 ends.
Outside the scope of BS7671 then SY, CY & YY can be used.
Personally if the SY is good quality and correctly installed and terminated then I don't have a massive issue with it being used for the fixed installation.
I have used it to overcome specific external influences.

What is more concerning to me is that an electrician is testing installations without enough experience to understand your perfect reasoning. SY is superior in many ways to flex.

 

[Steven Haynes]

Have a look at the manufacturer of the SY cable and see what's it's suitable for.
A few years-a-go some manufacturers used to put "not suitable for fixed wiring" in the description of there SY cables.
What exactly has been wired up in SY. Is it in trunking, buried, surface mounted,....

1. It's usually used on motors to reduce interference.
2. Have a look at the manufacturers data sheet and see what it's suitable for. See below as an example from Eland
3. Depends on data sheet.

View attachment 15272

1 motor control is usually 60204-1, not BS7671
2 its never had a BS number and never has complied, just some people love the stuff (expecially air con 'installers') and sling it in everywhere with no regard to how suitable (or not) it is
3 yes but you'd need to justify it. given the issues it with it, it would be hard to say how it just as good as complying. and chances are none of the ends are terminated correctly into CXT glands...

id be going back to whoever wired it incorrectly in the first place

Have a look at the manufacturer of the SY cable and see what's it's suitable for.
A few years-a-go some manufacturers used to put "not suitable for fixed wiring" in the description of there SY cables.
What exactly has been wired up in SY. Is it in trunking, buried, surface mounted,....

1. It's usually used on motors to reduce interference.
2. Have a look at the manufacturers data sheet and see what it's suitable for. See below as an example from Eland
3. Depends on data sheet.

View attachment 15272

Hi Spoon, thanks for your reply, you went through a lot of effort.
It is used for providing the controlled supply to motors. Sometimes inverter driven and sometimes DOL.

 

[Steven Haynes]

Hi Andy, you've raised a very valid point there and as far as I'm concerned, end the discussion. Why were the electricians even looking at the machine wiring. They should only be concerned with the building fixed wiring, surely. Are they going to start critiquing the control panel next.
Thank you.

 

[Andy™]

Hi Andy, you've raised a very valid point there and as far as I'm concerned, end the discussion. Why were the electricians even looking at the machine wiring. They should only be concerned with the building fixed wiring, surely. Are they going to start critiquing the control panel next.
Thank you.

how are the motors controlled? control panel? this does sound like its 60204-1 and not BS7671, if they are testing the fixed wiring to BS7671 then their responsibility ends at the isolator to the control panel

 

[Sidewinder]

Hi Andy, you've raised a very valid point there and as far as I'm concerned, end the discussion. Why were the electricians even looking at the machine wiring. They should only be concerned with the building fixed wiring, surely. Are they going to start critiquing the control panel next.
Thank you.

Another worrying thing for me is that the sparks doing the I&T didn't know clause 110.2, xi.
Yes, I do know that one from memory; that's how sad I am!
If you remove the SY from the motor feeds, then you might find yourselves in breach of the manufacturer's instructions for the variable speed drives.
You also might find that you get electromagnetic interference on other equipment because you have removed the screened able.
SY, CY, or similar screened cable is "mandated" by some drive OEMs.
Though, some drive & motor OEMs have their own interconnecting cables, which must be used between the drive and motor for functional and warranty.
These are remarkably similar to SY &CY cables.
The Thames barrier people wanted 450/750 V rated cable on the retrofit we did there, they were told that we used our cable, which was not classified the same way as general use wiring.
The datasheets for the drives, motors and cables were sent with the proposal, the job went in as we specified it.

If these cables are fed from the machine control panels, then they are outside the scope of BS 7671, due to clause 110.2, xi, and they fall under the scope of BS EN (IEC) 60204-1.
As a result, they should not be I&T'd under BS 7671, at best, a comment for further checks, NOT an FI on the EICR.
If the electricians are I&Ting this wiring under BS 7671 then they are wrong, their competence in the understanding of BS 7671 needs to be questioned.
Also, if they are doing the motor supplies, because they feel these fall under BS7671, why are they not doing the switch wiring etc?
Why have they not picked up that all the "wrong" colour wires are used? (That is, if, the machine has been built in compliance with BS EN 60204-1?)
There are a LOT more breaches of BS 7671 if the machine has been built in compliance with BS EN 60204-1 that should have been highlighted.
If the machine isn't in compliance with EN 60204-1, then it is likely not to be compliant with the Machinery Directive, therefore, not compliant with Reg 10 of PUWER, which means the employer is in breach of PUWER, as this should have been highlighted by the person that undertook the PYUWER inspection of the machine as required by PUWER, (statute law).

I might have duplicated comments here. If I have sorry. I'm not too well, and I need to do something else for a bit, and if I don't post this now, I don't know when I will!