Advice about safety please.

[davidatperces]

I am not an electrician but I am after a bit of advice. Would Ibe correct in thinking that a vehicle hook-up lead, used to keep the cooling units running when vans are parked up at its home base, should have the cable clamp on a plug should be on to the outer insulation and not onto the individual wires (earth, neutral and live) I do not think it is but would welcome any feedback and any reference to what regulations the lead/plug clamp might be under.

 

[Avo Mk8]

You are correct that the clamp should be on the insulation.
(and incidentally the 'earth' wire in the plug should be longer than the others, so it's the last to pull out in the event of the clamp failing)

How about BS7671 Chapter 13 "Fundamental Principles". Clause 134.1.4 :"Every electrical joint and connection shall be of proper construction as regards conductance, insulation, mechanical strength and protection."

 

[pc1966]

As above, yes. Clamping on the wires, or indeed if the wires (i.e. "primary insulation") are exposed outside of any equipment or plug, would fail an electrical or PAT inspection.

See also this example in the H&S guidance (page 3 of the PDF document):

https://www.hse.gov.uk/pubns/indg236.pdf

 

[davidatperces]

You are correct that the clamp should be on the insulation.
(and incidentally the 'earth' wire in the plug should be longer than the others, so it's the last to pull out in the event of the clamp failing)

How about BS7671 Chapter 13 "Fundamental Principles". Clause 134.1.4 :"Every electrical joint and connection shall be of proper construction as regards conductance, insulation, mechanical strength and protection."

Thank you Avo Mk8. Let me just state that I am in no way going to do anything with the leads, I am not qualified, but I had reported the lead as not suitable after my daily van check and given it to a manager (it was labeled as not to be used by me), only to find the same lead back on the van two more times, a colleague also checked the lead and could see copper. I have been told that they are ok as a "qualified" member of staff had checked them which of course made me query the so-called qualification and how this person was possibly checking other equipment. As I am not qualified I thought it would be proper to seek advice to give me a bit more confidence to take this further and hopefully stop someone from getting hurt.

 

[davidatperces]

As above, yes. Clamping on the wires, or indeed if the wires (i.e. "primary insulation") are exposed outside of any equipment or plug, would fail an electrical or PAT inspection.

See also this example in the H&S guidance (page 3 of the PDF document):

https://www.hse.gov.uk/pubns/indg236.pdf

Thank you pc1966 for this information. I have replied to an earlier reply with a bit more detail but very much appreciate your input.

 

[pc1966]

Thank you pc1966 for this information. I have replied to an earlier reply with a bit more detail but very much appreciate your input.

You are quite right to be concerned and whoever told you it is OK is clearly not qualified and talking out of the wrong orifice.

That H&S guide clearly shows what is expected of a 13A plug and also covers more about the requirement for periodic inspection and testing of electrical equipment in any commercial or industrial environment.

 

[pc1966]

There is a lot more about testing here:

PAT (Portable appliance testing) - HSE's answers to popular questions

Health and Safety Executive (HSE) answers; frequency of tests, legal requirements, record keeping, new equipment, who can test, hire tools

www.hse.gov.uk

The law in this respect is a bit odd, although such oddness also applies to fixed wiring rules. It does not mandate that you have to inspect and test, however it is a legal requirement to maintain a safe working environment. Realistically the only way to do so and to have evidence to back you up if there ever is a serious incident is to do periodic inspection & testing.

It used to be called PAT from "portable appliance testing" since fixed wiring is covered by the EICR (electrical installation condition report) but that resulted in things like fixed wall-mounted heaters, etc, not being inspected by either regime (not portable, not part of fixed wiring). So that has been replaced by the"In-Service Inspection and Testing of Electrical Equipment" guidance, or ISITEE which is a lot less memorable!

 

[James]

Some pictures would be great, we like pictures.

there may be other reasons why the cable and plug are not acceptable.

one that springs to mind is the temperature rating of the cable as it is below freezing overnight in most of the U.K. at the moment.
unless it is designed for low temperature operation it could be damaged by being flexed at low temperature.

 

[davidatperces]

Some pictures would be great, we like pictures.

there may be other reasons why the cable and plug are not acceptable.

one that springs to mind is the temperature rating of the cable as it is below freezing overnight in most of the U.K. at the moment.
unless it is designed for low temperature operation it could be damaged by being flexed at low temperature.

Just a few photos showing the problem

 

[pc1966]

Just a few photos showing the problem

They are all unsafe and would be failed on any inspection.

• Cable sheath not clamped, so not adequately supported
• Primary insulation outside of the cover/enclosure
• Plug body integrity compromised, potentially leading to contact with live parts

 

[Rockingit]

^^^^ What he said. The sad thing is that it would take minutes to put those 32's back on properly! Also, SY cable (the one with the metalic sheath) isn't suitable for that purpose (even though I see it daily).

 

[pc1966]

^^^^ What he said. The sad thing is that it would take minutes to put those 32's back on properly!

Exactly, not a hard job for anyone electrically competant.

Also, SY cable (the one with the metallic sheath) isn't suitable for that purpose (even though I see it daily).

Its an odd one, yes it looks macho but there are few cases where it actually makes sense. It is not up to the protection of SWA and (most importantly) not UV resistant, but you still need it glanded at one end to earth the metal braid.

The rubber H07RN-F style is a much better choice, tough yet flexible, UV resistant and also fairly resistant to common stuff you find on the floor of workshops, etc. Quite a few places also sell it be the metre so you can buy what you need in the size(s) needed for the job.

Edit: Also good for some cases is the "arctic" cable, flexible down to lowish temperatures and usually in bright colours so easy to spot on poorly lit floors, etc. For example:

BS6004 TABLE 44 ARCTIC GRADE FLEXIBLE CABLES

Arctic Grade Flexible Cable manufactured to BS6004 table 44. Arctic grade cable has plain annealed flexible copper conductors, PVC insulation, low temperature PVC outer sheath and is available in either blue or yellow sheath. Please note: The Superlec Direct team are not qualified as...

www.superlecdirect.com

 

[Rockingit]

Exactly, not a hard job for anyone electrically competant.

Its an odd one, yes it looks macho but there are few cases where it actually makes sense. It is not up to the protection of SWA and (most importantly) not UV resistant, but you still need it glanded at one end to earth the metal braid.

The rubber H07RN-F style is a much better choice, tough yet flexible, UV resistant and also fairly resistant to common stuff you find on the floor of workshops, etc. Quite a few places also sell it be the metre so you can buy what you need in the size(s) needed for the job.

Edit: Also good for some cases is the "arctic" cable, flexible down to lowish temperatures and usually in bright colours so easy to spot on poorly lit floors, etc. For example:

BS6004 TABLE 44 ARCTIC GRADE FLEXIBLE CABLES

Arctic Grade Flexible Cable manufactured to BS6004 table 44. Arctic grade cable has plain annealed flexible copper conductors, PVC insulation, low temperature PVC outer sheath and is available in either blue or yellow sheath. Please note: The Superlec Direct team are not qualified as...

www.superlecdirect.com

BS7909 is based around use of H07 for it's mechanical properties. As essentially a rubber cable it's elastic nature makes it superior for dealing with knocks and abrasions, pulling etc. Arctic cable is frowned upon, not because it's particularly bad but because it's still a PVC cable and easily abraded and cut. SY cable has no advantage whatsoever in this application and can give users a false sense of 'robustness' that simply doesn't exist. The braid is designed for signal shielding, not mechanical strength.

 

[pc1966]

Arctic cable is frowned upon, not because it's particularly bad but because it's still a PVC cable and easily abraded and cut.

That is useful to know. I see it used quite a bit but ceratinly the rubber stuff seems to survive better. Shame the don't make a coloured version!

SY cable has no advantage whatsoever in this application and can give users a false sense of 'robustness' that simply doesn't exist. The braid is designed for signal shielding, not mechanical strength.

We use a def-stan cable with copper braid for the EMC aspect, but that is fixed not flexible use, and not carrying mains power as such (though some of the lines are direct off mains via rectifier / thyristor bridge).

So far not found a genuine use-case for SY!

 

[Rockingit]

Shame the don't make a coloured version!

This has been explored! The black colour is part of it's intrinsic UV protection qualities. I'm also a fan of H07 for industrial installation environments as an alternative to Hi-Tuff or SWA (depending on methods etc, obviously) due to being far easier to work with in limited space, bend radius etc.

The last time I found a legit use for SY was when after having finished a nice neat install on tray, all dressed off, the wet-pants team suddenly realised they'd forgotten about a whole load of ELV sensors and control that needed running around - so had to squeeze some multicore DC stuff onto the same tray as all the 3ph.

 

[pc1966]

This has been explored! The black colour is part of it's intrinsic UV protection qualities.

Ah, I had suspected that.

I'm also a fan of H07 for industrial installation environments as an alternative to Hi-Tuff or SWA (depending on methods etc, obviously) due to being far easier to work with in limited space, bend radius etc.

Good point, we use it for new with our floodlights on temporary fencing, though might get replaced with Flexishiled eventually.

I also try and use tri-rated for internal wiring when possible for similar reasons!