Electrical Insulating tape

[ban-all-sheds]

Hmm, I found that BS is actually advocating the use of tape.
While it does not mention using it for insulation, it does say to use it in 514.4.6

But as you say, it's not suggested as an insulator.

 

[ban-all-sheds]

True, but I doubt that they would even consider using 'conductive' tape, even if the joint was going to be enclosed in resin - so I presume they must have some regard for the insulating properties of whatever tape they use.

I'm not claiming that insulating tape has no insulating properties. But so does newspaper.

 

[JohnW2]

It appears that BS EN 60454-2:2007 ("Pressure-sensitive adhesive tapes for electrical purposes") is the relevant Standard, and that many/most of the up-market "insulating tapes" seem to claim conformity with this Standard - suggesting that there are perceived legitimate electrical/'insulating' uses of such tapes. If one had £224 to spend on a copy (or, as stillp would have suggested, was is prepared to make a pilgrimage to an appropriate library), it would be interesting to know what this Standard has to say.

 

[SimonH2]

Given that there are so many requirements for "insulation" in BS 7671, it is incumbent on those who say "insulating tape can be used" to say which insulating role they claim it can play.

I think people have said, where insulation is needed and tape is a practical method of providing it. Over to you, please state where in BS7671 it states that insulation may not be by use of self adhesive tape wrapped around the part in an appropriate manner.

Have you looked in part 2 of BS7671 to see how insulation is defined ? It says "Suitable non-conductive material enclosing, surrounding or supporting a conductor". So if (for example) I have a conductor and wrap it well with adhesive insulating tape - then the insulation is now "enclosing" or "surrounding" the conductive part. The only question then remaining, unless you can cite something specifically prohibiting use of such tape, is the one about "suitable".
So again, over to you - as you are the one claiming that such tape may not be used as insulation, please cite references that actually say so.

I'm not claiming that insulating tape has no insulating properties. But so does newspaper.

And guess what, my mains supply is insulated with paper - OK, not recycled newspaper, but I bet there's naff all practical difference Bear in mind that the primary (and in some cases, ONLY) insulation in the cable is paper, AND it is exposed to anyone in the household.

 

[SUNRAY]

I'm not claiming that insulating tape has no insulating properties. But so does newspaper.

And on more than one occasion I have used newspapers or cardboard as a barrier when working in live enclosures.

Paper was used as the most popular insulator in telephone cables for a long time.

 

[mattylad]

I looked at the previously quoted part of BS7671, specifically 412.2.1.3 and it says nothing about tape, no mention of tape not being able to be used.
Mind you I currently only have access to the Yellow book at work, we wont get the new one until November after an upgrade course - has it changed?

So I too would ask that BAS quotes the entire specific bit of BS that says not to use tape (and ask that the mods allow this as I have a genuine need to know this).
I have shown where it IS specifically reccomended for a use, and I'd like to know where it is specifically not.

Electrical tape (as it is known with many suppliers) is made from PVC, so are a great many rolls of wire used to wire equipment - PVC, because it IS an insulator.
It has a layer of adhesive added to one side. Cheap tape is very thin, not very flexible and has poor adhesive, good quality tape the opposite.
I have wired many control panels etc. using PVC coated wire.

So why would tape be frowned upon being used? Perhaps because of the workmanship of some, not putting enough on or it being too cheap a material that it comes off over time.
That unfortunately can be said about most everything, I can buy double gang socket fronts for £1 that would also likely fail after a short while also I have come across live wires that have voltages upto 415v
regularly that are covered in tape yet still insulated and not presenting any danger to anyone.

On the other hand I have also come across blooming great messy bundles that both look bad and can be dangerous as a live part is not insulated well.
So IMO it's not the actual tape that is the problem, its the application of of it by people that are not very good at it, these are also likely people that also miss the sleeving off earth wires, don't bother with grommets etc.

Other legitimate uses have also been mentioned for it already I'll add some more.

I use it when running sets of wiring in trunking, when you have multiple welding bays to provide a L,N,E for to be able to distinguish which is which at any point in the trunk they have some coloured tape wrapped around them at about every 8 foot or so, different tape per set.

When taking a fitting down, the exposed end of the supply wires are taped to insulate them to prevent a numpty touching them after some other numpty has turned the power on again (I cannot always add a lock nor remove an MCB to prevent this), this has to be done as when changing a fitting I or my master may be called away to a more important issue anytime (such as a punch or press electrically breaking).

The handle on Tig welding equipment has a plastic cover over the on/off button - this is taped over to prevent it coming off or moving through constant use.
The ends of 10mm+ wires that have squash on ring terminals (ok it's actually 10mm copper pipe that's been squashed and drilled through) are likely to last longer if also given copious layers of good tape at the join.
It has multiple uses in welding bays (it must as the welders keep stealing it from the electrical dept )

Woven sleeving (high temperature polyamide I think, expands so you can add more wires through - needs heat sealing at the ends to prevent fraying) - tape can be wrapped around the ends so that it goes through holes in cabinets easier.
The ends of wire singles can be taped together so that they all go the same direction at the same time when passing them through cabinet holes etc.

This tape is general purpose and has multiple uses.

 

[mattylad]

But as you say, it's not suggested as an insulator.

It is also not suggesting it as "not an insulator".

 

[ban-all-sheds]

I think people have said, where insulation is needed and tape is a practical method of providing it. Over to you, please state where in BS7671 it states that insulation may not be by use of self adhesive tape wrapped around the part in an appropriate manner.

I already have, and JohnW2 dismissed it as [PARAPHRASING]Not the scenario we're discussing[/PARAPHRASING].

Which is why I started asking for those saying it may be used to say what they would use it on and why.

 

[ban-all-sheds]

It is also not suggesting it as "not an insulator".

Indeed it's not.

Care to make any other fatuous observations, e.g. "It is also not suggesting it as 'not a nutritious snack'"?

 

[ban-all-sheds]

I looked at the previously quoted part of BS7671, specifically 412.2.1.3 and it says nothing about tape, no mention of tape not being able to be used.

The problem is not that is says "tape may not be used", it's that tape does not have the properties necessarily required.

I use it when running sets of wiring in trunking, when you have multiple welding bays to provide a L,N,E for to be able to distinguish which is which at any point in the trunk they have some coloured tape wrapped around them at about every 8 foot or so, different tape per set.

That's not using it as an insulator.

When taking a fitting down, the exposed end of the supply wires are taped to insulate them to prevent a numpty touching them after some other numpty has turned the power on again (I cannot always add a lock nor remove an MCB to prevent this), this has to be done as when changing a fitting I or my master may be called away to a more important issue anytime (such as a punch or press electrically breaking).

That sounds like Basic Insulation to me - do you agree?

What does 416.1 say about that?

The handle on Tig welding equipment has a plastic cover over the on/off button - this is taped over to prevent it coming off or moving through constant use.
The ends of 10mm+ wires that have squash on ring terminals (ok it's actually 10mm copper pipe that's been squashed and drilled through) are likely to last longer if also given copious layers of good tape at the join.
It has multiple uses in welding bays (it must as the welders keep stealing it from the electrical dept )

Woven sleeving (high temperature polyamide I think, expands so you can add more wires through - needs heat sealing at the ends to prevent fraying) - tape can be wrapped around the ends so that it goes through holes in cabinets easier.
The ends of wire singles can be taped together so that they all go the same direction at the same time when passing them through cabinet holes etc.

This tape is general purpose and has multiple uses.

All of those other examples are not using it as an insulator.

 

[JohnW2]

I'm not sure where the assertion that "that tape does not have the properties necessarily required" comes from (or what is the supporting 'evidence and proof' for it), but if it is actually true, then it begs the question as to why the Standard I recently mentioned even exists - BS EN 60454-2:2007 ("Pressure-sensitive adhesive tapes for electrical purposes"). What 'electrical purposes' could be within its scope if no 'insulating tapes' have "the properties necessarily required" - keeping the wrapping on electricians' sandwiches, perhaps?

 

[SimonH2]

The problem is not that is says "tape may not be used", it's that tape does not have the properties necessarily required.

For one VERY SMALL subset of potential applications - it is a very very long way from saying that insulating tape cannot be used as insulation in the general case where it would be appropriate. I would suggest that very few of us have ever relied on 412.2.1.3 (as referred to by 412.2.1(iii) - in fact I doubt that many of us have ever relied on 412 at all.
It's as relevant to arguing that insulating tape cannot be used as insulation as quoting 417.3.1 in isolation and arguing that separate items of equipment cannot be within arms length of each other

 

[mattylad]

The problem is not that is says "tape may not be used", it's that tape does not have the properties necessarily required.

I too would like to know where and how you ascertain that it does not have the properties required to insulate? Especially when it is made of an insulating material.
412.2.1.3 says nothing that would lead me to think that correctly applied insulating tape would not have the required properties to insulate something.

It seems that your making claims that you cannot backup.

Stop quoting numbers and explain in words - why can it not insulate?
come on, give us some facts.

 

[mattylad]

Indeed it's not.

Care to make any other fatuous observations, e.g. "It is also not suggesting it as 'not a nutritious snack'"?

As for this! your being silly now.

 

[ban-all-sheds]

I'm not sure where the assertion that "that tape does not have the properties necessarily required" comes from (or what is the supporting 'evidence and proof' for it), but if it is actually true, then it begs the question as to why the Standard I recently mentioned even exists - BS EN 60454-2:2007 ("Pressure-sensitive adhesive tapes for electrical purposes"). What 'electrical purposes' could be within its scope if no 'insulating tapes' have "the properties necessarily required" - keeping the wrapping on electricians' sandwiches, perhaps?

Purposes outwith the scope of BS 7671?