LED tube to replace fluorescent tube in existing batten

[SUNRAY]

It sounds as if I made the mistake of thinking you were referring to the drawing you actually included in post #14

Kind Regards, John

I've just realised a confusing error in that drawingView attachment 278921

referring to and harvested from post #11

 

[JohnW2]

And how useful do you think a sign saying 'Danger - Low Voltage' would be?

That's the problem. I really don't think that the 'correct' terminology for voltage bands does anything to help the public, or their safety - in fact, quite the converse.

As I've said many times, and having canvassed a good few people over the years, I don't think there is any doubt that the great majority of the general public believe that "Low Voltage" refers to something which is very unlikley to do them (or even their children) any harm.

Kind Regards, John

 

[JohnW2]

referring to and harvested from post #11

Maybe you were' referring' to that, but the only diagram I actually paid attention to was what you actually posted in that message

Kind Regards, John

 

[winston1]

And how useful do you think a sign saying 'Danger - Low Voltage' would be?

Perhaps it should say 'Danger - 750volts'.

 

[winston1]

That's the problem. I really don't think that the 'correct' terminology for voltage bands does anything to help the public, or their safety - in fact, quite the converse.

Indeed, the IET or who ever has got the terminology wrong. Low voltage should be 0 to 50v say, and high voltage above 250v. Not sure what to call 50 to 250v though.

 

[JohnW2]

Perhaps it should say 'Danger - 750volts'.

That would be better - but, as I said, what would is most appropriate/meaningful to the general public is "Danger - High Voltage", since they all understand that 'high voltages' are dangerous (and most believe that Low Voltage ones aren't), without necessarily knowing what numerical voltages are 'high' and 'low'.

 

[JohnW2]

Indeed, the IET or who ever has got the terminology wrong. Low voltage should be 0 to 50v say, and high voltage above 250v.

Perhaps, but if we consider (as we do) 50V-250V to be 'dangerous', then maybe 'high voltage' (which is what tyhe public would perceive to be dangerous) should start at 50V?

Not sure what to call 50 to 250v though.

As above, I'd be inclined to also call that HV. If one was forced to have a third band, I suppose that 50-250V would be Medium Voltage, but I think that would confuse/mislead the public even more.

 

[john4703]

Another factor is where they are fitted. I was asked to look at fluorescent fittings in a hall that was used by a number of youth groups. Fluorescent tubes in fittings with no protection could easily be broken by a football or similar weapon.

I looked at the cost of fitting mesh covers and then realised that fitting LED tubes was a lot cheaper and they are made of some sort of plastic that will not shatter if hit by a football.

 

[JohnW2]

I looked at the cost of fitting mesh covers and then realised that fitting LED tubes was a lot cheaper and they are made of some sort of plastic that will not shatter if hit by a football.

I've never seen one hit by a football, but I have seen ('some sort of plastic') LED tubes shattered by impact with something ( don't know what).

I would have thought that any sort of light fitting in an environment in which footballs/whatever might be flying around in their vicinity ought to have some sort of mechanical protection, shouldn't they?

Kind Regards, John

 

[john4703]

I've never seen one hit by a football, but I have seen ('some sort of plastic') LED tubes shattered by impact with something ( don't know what).

I would have thought that any sort of light fitting in an environment in which footballs/whatever might be flying around in their vicinity ought to have some sort of mechanical protection, shouldn't they?

Kind Regards, John

Thanks John, I'll look at them agasin. The ones I fitted were flexible and I could bend them but I'll chack them again

 

[RandomGrinch]

That would be better - but, as I said, what would is most appropriate/meaningful to the general public is "Danger - High Voltage", since they all understand that 'high voltages' are dangerous (and most believe that Low Voltage ones aren't), without necessarily knowing what numerical voltages are 'high' and 'low'.

...and even then, not all high voltages are necessarily 'dangerous'. I've restored a couple of beautiful vintage Whimshurst machines to working order.
It's not exactly pleasant to get in the way of a 5" spark, but to most, it wouldn't be harmful!

We also use 5kV EHT PSU in several student experiments, the output current is limited to 2mA.

 

[winston1]

Another factor is where they are fitted. I was asked to look at fluorescent fittings in a hall that was used by a number of youth groups. Fluorescent tubes in fittings with no protection could easily be broken by a football or similar weapon.

I looked at the cost of fitting mesh covers and then realised that fitting LED tubes was a lot cheaper and they are made of some sort of plastic that will not shatter if hit by a football.

What did you do/did they say about the reduced output?

 

[JohnW2]

...and even then, not all high voltages are necessarily 'dangerous'.

Indeed not - but that is the potentially confusing and potentially dangerous information that the general public could do without

I've restored a couple of beautiful vintage Whimshurst machines to working order. It's not exactly pleasant to get in the way of a 5" spark, but to most, it wouldn't be harmful!

Not harmful to the majority of people. However, there are a good few walking about whose hearts are (often unknown to them) so electrically unstable that they are constantly at risk of spontaneously developing fatal rhythm disturbances - so any electric 'shock' can be 'the last straw'

We also use 5kV EHT PSU in several student experiments, the output current is limited to 2mA.

I'm sure I've reported before that, in my misspent youth, I was often seen to be playing around inside old TVs, and one of those I 'played with' (I'm pretty sure with a Model No of "TV1", I think perhaps Phillips, and in a very nice floor-standing mahogany cabinet!) was potentially quite lethal since, rather than the 'usual' derivation of EHT (~25 kV) for the CRT from the Line Output Transformer (with a very low current-supplying ability), it had a mains-driven ~25 kV PSU (lots of 'voltage multipliers' etc.)!

Kind Regards, John

 

[RandomGrinch]

Not harmful to the majority of people. However, there are a good few walking about whose hearts are (often unknown to them) so electrically unstable that they are constantly at risk of spontaneously developing fatal rhythm disturbances - so any electric 'shock' can be 'the last straw'

Yes, we also have several magnetic experiments that locally generate fields of around 1.2T.
Which means along with our usual RA's and warning signs, we have to consider the risk to those who have medical devices, such as pace makers (rare in students), but more commonly, insulin pumps etc.

 

[JohnW2]

Thanks John, I'll look at them agasin. The ones I fitted were flexible and I could bend them but I'll chack them again

You're welcome. However, I imagine that the materials probably vary, so the ones you have may well be relatively 'shatter-proof'.

Kind Regards, John