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.

Chris Pearson: 
 

Does the code matter? Would anybody seriously want to see it left like that? ?

It might not … BS 7671 might not even apply !

Even more interesting so if its machinery Periodic inspection isn’t a thing and it’s just down to engineering judgment to work out how urgently the repair needs to be carried out. for example critical kit cant always be switched off due to certain operational constraints. 

MrJack96: 
 

Even more interesting so if its machinery Periodic inspection isn’t a thing and it’s just down to engineering judgment to work out how urgently the repair needs to be carried out. for example critical kit cant always be switched off due to certain operational constraints. 

That's only if the maintenance strategy is “to fail” or similar … the maintenance required depends on the safety risk assessment … it may be more stringent than BS 7671 “periodic verification”, but at the bottom line, the driving legislation (apart from the H&S@WetcAct) is:

• PUWER
• Electricity at Work Regulations
• Supply of Machinery (Safety) Regulations
• Other legislation dependent on the process risks involved (e.g. explosive atmospheres, COMAH, etc.)

In that case, the requirement to provide suitable containment (or sheathing) is nonsense in the first place?

Of course it is a necessary requirement  … but why?

It is not always a necessary requirement. Regs may think so, but I beg to differ.  It is perfectly possible to install unsheathed wiring, carrying potentially lethal voltages, in places where they are not going to be touched, or bleached by sunshine  or attacked by squirrels, and it will give many years of perfectly safe service….  in a closed void behind  a downlighter may be a good example. 

Another one is the NE bond one - sometimes perfectly fine and dandy, so long as you have a grip on the currents that will flow in the CPCs but not permitted by UK regs. Just not something to be taken as always OK by the uninformed.

Another would be the requirement to use the same size bonding on all pipes emerging from the ground, when those with an NE bond at next doors TNCS service head are much more likely to carry a large current, than say a short buried pipe to a private oil tank.

1.   If an installation confirms to the regulations it can be regarded as safe.

also sadly not always There may be parts that BS7671 declared out of scope that really do need to be considered in the wider  safety picture in some cases. E.g. those bayonet holders again.

2.   If it does not confirm it might or might not be safe  Only engineering judgement can tell.

But a lot of electricians (perhaps lacking engineering judgement) think that if it does not confirm it is, ipso facto, dangerous

Sadly far too true.

Although this sounds like I am being rather  confrontational, actually I suspect that in practice we would when presented with the same thing in the field agree broadly on what is or is not really dangerous.

And finally, that photo.

Unless it is indoors, it needs fixing smartish,   and even if it is indoors it still needs fixing reasonably smartly !  

If in your organisation the way to ensure that is to declare a C2 then do so, though really it may be the wrong code if it is not be dangerous in the sense of shock or fire, it may be more of a risk in the sense of the kit failing suddenly..

We could argue we do not know if the conductors in the box have been part torn from their terminals when the gland was pulled out, and are about to fail…

Mike.

gkenyon: 
 

AJJewsbury: 
Non-compliance, but not necessarily a C2. Say we had non-sheathed cables on a SELV circuit (e.g. traditional bell wire on a door bell circuit) - is that really even a codable situation?

   - Andy.

But this is LV ?

The point I was attempting to make was that there's nothing in the wording or positioning of 521.10.1 to say it only applies to LV circuits… using exposed non-sheathed cables in other situations would thus still be a non-compliance, but the danger would likely not be significant.

   - Andy.

AJJewsbury: 
 

gkenyon: 
 

AJJewsbury: 
Non-compliance, but not necessarily a C2. Say we had non-sheathed cables on a SELV circuit (e.g. traditional bell wire on a door bell circuit) - is that really even a codable situation?

   - Andy.

But this is LV ?

The point I was attempting to make was that there's nothing in the wording or positioning of 521.10.1 to say it only applies to LV circuits… using exposed non-sheathed cables in other situations would thus still be a non-compliance, but the danger would likely not be significant.

   - Andy.

Does Regulation 414.4.5 not apply in the general case where the voltage is less than 25 V AC or 60 V DC … no basic protection (including insulation) is necessary at all … give or take any additional requirements where a Part 7 applies of course.

Chris Pearson: 
 

Does the code matter? Would anybody seriously want to see it left like that? ?

Agree 100% Mr Pearson. It needs to be addressed, if not purely for safety, then at least for continued service and prevention of downtime.

Does Regulation 414.4.5 not apply in the general case where the voltage is less than 25 V AC or 60 V DC … no basic protection (including insulation) is necessary at all … 

Basic insulation might be omittable for safety reasons (even if it's almost certainly still needed for functional reasons) - but the words of 521.10.1 still seem to require a sheath (or conduit, ducting or trunking) regardless. Even bare conductors would be unsheathed.

   - Andy.

AJJewsbury: 
 

Does Regulation 414.4.5 not apply in the general case where the voltage is less than 25 V AC or 60 V DC … no basic protection (including insulation) is necessary at all … 

Basic insulation might be omittable for safety reasons (even if it's almost certainly still needed for functional reasons) - but the words of 521.10.1 still seem to require a sheath (or conduit, ducting or trunking) regardless. Even bare conductors would be unsheathed.

   - Andy.

 

 

Bare conductors may be installed on insulators … Regulation 521.10.201

I do agree, though … and for fire safety as I've said it may well be necessary even for ELV systems (perhaps more so than LV systems, particularly if the current available is above a few amperes. It's perhaps less likely to be immediately dangerous if ELV …