Single cores outside enclosure

MrJack96: 
 

I believe it’s a control cable operating solenoids. Interesting discussion alot of factors to consider. I doubt there would be a presence of salty water and being industrial mostly operational staff on sites so from what you’re saying a C2 would be relevant. However if full of rain water would this then become a C1? 

That's interesting … and makes the decision even more tricky.

We really can't advise on this Forum further, because we don't know what the control cables are actually controlling.

Usually, control cables are run PELV … and if metal containment such as SWA, conduit or trunking are used, they will be earthed … so that a faulty cable shows up by operating a protective device. Controls are normally arranged to “fail safe” - but is there a fault condition here that could cause a safety issue that we can't see?

Also, if the control cables are part of “machinery" (or a wider related process) as defined in the Supply of Machinery (Safety) Regulations, then BS 7671 doesn't apply here and BS EN 60204-1 applies. Earthing and bonding requirements are typically more stringent, and I'd expect the armour of the cable to be earthed properly for a controls installation to BS EN 60204-1.

MrJack96: 
 

I believe it’s a control cable operating solenoids. Interesting discussion alot of factors to consider. I doubt there would be a presence of salty water and being industrial mostly operational staff on sites so from what you’re saying a C2 would be relevant. However if full of rain water would this then become a C1? 

That's interesting … and makes the decision even more tricky.

We really can't advise on this Forum further, because we don't know what the control cables are actually controlling.

Usually, control cables are run PELV … and if metal containment such as SWA, conduit or trunking are used, they will be earthed … so that a faulty cable shows up by operating a protective device. Controls are normally arranged to “fail safe” - but is there a fault condition here that could cause a safety issue that we can't see?

Also, if the control cables are part of “machinery" (or a wider related process) as defined in the Supply of Machinery (Safety) Regulations, then BS 7671 doesn't apply here and BS EN 60204-1 applies. Earthing and bonding requirements are typically more stringent, and I'd expect the armour of the cable to be earthed properly for a controls installation to BS EN 60204-1.