BS EN 60598-1:2000, what constitutes "sheltered location"; or IP44 lights failing !

[SimonH2]

Looking around at various sources, it looks like IPx4 should be suitable for an enclosed garden - it seems most vendors consider a typical garden as being "sheltered" as the walls, trees etc provide protection from the worst of the winds.
Anyway, I've installed some festoon lighting using a festoon harness and LED bulbs from TLC. Both are IP44 rated.

It all looks very nice and SWMBO likes them - especially the fact that they look like "real, old fashioned light bulbs"

But, so far we've had about 8 lamp failures out of 52 installed - there's another short string I've had up for years where I've replaced the old 25W lamps with 2W LED ones.

On investigating, I found that a "failed" lamp I removed actually worked - briefly before the RCD tripped (it was in an earthed metal holder when I tested it). It showed low IR between pins and cap - the reason for which was obvious when I opened it up :

Everything was wet, particularly the disk of insulating sheet which was between the LED module and electronics PCB - plus there was a small amount of water in the bottom of the bulb case. After drying out, works fine.
When the next ones failed, I noticed that it wasn't always a total failure, the red one at the right here is still glowing dimly :

I have raised the issue with TLC. Their first response is that it (the harness) is not suitable for outdoor use like this as it's not sheltered from rain. When I replied that it's more a problem with the LED lamps which are described as "Direct replacement 25W coloured incandescent lamps", they've just offered to take them back and allow me to order 25W incandescents. I've just emailed back to say that I chose LED to avoid having over 1kW or lights going

I'm thinking that I've hit a gap between the IP ratings and practical usage. The lamps may well pass the IPx4 test which only requires splashing for 5 or 10 minutes. But in real use, they will breath due to changes in temperature and environmental pressure - and as there's no seal whatsoever between cap and "bulb", are bound to draw in moisture even if there's no rain. I did note that when I unplugged the bulbs, a tiny amount of water had been drawn up into the space inside the harness socket seal where it seals on the the neck of the bulb casing.

At the moment I'm thinking that I'll have to dry them out and try sealing the bulbs properly. I've had some "old fashioned" 25W incandescent bulbs out in all weathers for years - and having a sealed bulb they've not had this problem. But at 300W for 12 bulbs, or 1.3kW if I'd added the 40 bulb set with them, not something I want on for too long


As an aside, the bulbs are "non dimmable" but actually dim quite nicely on a variac. Come on at around 25V and then vary in brightness with voltage. I've been running the main set outside at 55V - dad made a 110V transformer for running tools from, and made it switchable between 110V and 55V - and they are just about right for our setting on that. Full brightness with 40 lamps is "a bit bright" really, though the neighbours love them.
Internally there's an inductor (I assume, it looks like one and is labelled RX on the board) and a capacitor to drop the voltage, then a bridge rectifier, smoothing cap (it's noticeable that they don't have 100Hz flicker like many LEDs*), and current limiting resistor to the LED strings.
* I've found that many LED bulbs have a very pronounced strobe effect when there's any motion. I assume that they just have a bridge rectifier and current limiting resistor - no smoothing cap.

 

[flameport]

The incandescent bulbs are not likely to suffer from moisture due to the vast amounts of heat created when they are on, any moisture that got in would be boiled away.

If the LED ones are not sealed, it's inevitable that water will get in via capillary action, and the little to no heat generated won't dry them out.

 

[333rocky333]

Yerars ago we used to use Led golfball lamps on pub fascias called "Greenock Turnballs", they were great but have not seen them sold for years.
On my garage i still have 15w filament pygmy lamps they have lasted over 20 years.

 

[SimonH2]

The incandescent bulbs are not likely to suffer from moisture due to the vast amounts of heat created when they are on, any moisture that got in would be boiled away.

Indeed, plus the bulb itself is sealed so any moisture doesn't really have anywhere to go.

If the LED ones are not sealed, it's inevitable that water will get in via capillary action, and the little to no heat generated won't dry them out.

Yes. Not just capillary action, there's the natural "breathing" with changes in temperature and atmospheric pressure. When flying, we were always taught to leave the fuel tanks full as that minimised the air volume and hence amount of moist air that could be drawn in as the temperatures fell, and hence minimise the amount of condensation that could occur.

On my garage i still have 15w filament pygmy lamps they have lasted over 20 years.

Dunno how old my incandescent lights are, but I bought them when I was two jobs ago - so "more than 13 years". I've been slowly getting through them but I still have some still in their boxes.

TLC have generated a returns note for the lamps but that still leaves me with what to replace them with - and will others be the same ? There does seem to be a limited choice of GLS shaped, low power, coloured bulb (as in, they are coloured when off), LED lamps. I am tempted to try and seal these before I send them back. Or perhaps just drill a tiny hole in the bottom

 

[SimonH2]

Interestingly, as I sit writing this, I notice that the end red lamp that was dim is now at normal brightness - but the next red along (5 bulbs to the left) is now dim

 

[ericmark]

I found an old set of outside lights, and when I came to fit LED bulbs I found the shield around the SES holder was too long to allow them to fit, clearly designed so the larger wattage wide bulbs would not fit, designed for 15W bulbs, I had to saw a section off each shield to fit 3W LED candle bulbs. But there has been no problem with them outside left on all the time.

However bulb not in direct contact with elements and that has never been a good idea, rain on hot bulbs can make them crack, so always some cover to stop direct contact with rain water.

If I run for shelter in a rain storm, I am looking for some where that protects me from rain, I may still get driven rain, but not direct from above, so in a car port or a pagoda OK but not in direct rain.

 

[SimonH2]

It doesn't seem to have been a problem for (eg) illuminations that have been going on for years, nor with the 25W incandescent bulbs I've had outside for many years. The only problem I've had was when damp got into one of the lamp holders on my old site lighting - into the back where it's moulded onto the cable, not the socket.
Having replaced the blown bulb and found them all working fine, I was pondering how to find the fault when ... I heard a bit of a fizzing from one lampholder. Luckily it was the last one so I just shortened the string by one bulb.

The problem I have is ...
If I send these back, what do I replace them with ? I can't help thinking that there will be a lot of other LEDs with the same problem - and the same IP44 rating.

 

[ericmark]

Protected against spray up to 60° from vertical. The question is what is spray? and which way should a bulb be placed i.e. what is regarded as top on a bulb? All my outside Christmas lights have a plastic coloured cup around the bulb, so bulb is not exposed to elements.

With the old tungsten bulb if water hit the hot bulb it would often crack the bulb, a fine mist of water OK, but drops of water and they would fail, if rain started light so bulb gradually cooled, then they would survive, but outside when using 55 - 68 volt to earth (110 volt bulb) where the cage around the bulb did not protect from water, we used rough service bulbs, I have just googled and a tungsten rough service bulb 60W costs from Amazon £1.80 each nearly as expensive as LED.

I looked for LED rough service and could only find USA adverts, no adverts with price in pounds said rough service, or 230 volt, all seemed to be 120 volt.

With 40 lights your looking at £100 plus for bulbs unless you use bog standard bulbs, I look at adverts and see this

which seems to show lights like yours, it states low voltage, again like yours, then you realise they don't know what low voltage is, as it states part of their 24V connectable range. I thought 24 volt was extra low voltage? I finally found some "LEDlite Coloured golf ball lamps, with an impact resistant polycarbonate cover, available in a choice of vibrant colours" this advert for a festoon has the bulbs listed below, 1 watt each, they are the only 230 volt bulbs I could find actually to say

Ideal for Festoon lights, Christmas Trees, Interior and Exterior Decorative Lighting
Energy Saving ONLY 1 watt Suitable for internal and External use

it does not give an IP rating.

 

[SimonH2]

Bulb page does give the same IP44 rating, and much the same description as the GLS version I have bought. What is now obvious is that the "photo" on the product page is not a photo, it's a computer render of a model. The actual lamp has a ring of dimples around the cap where it's fixed to the polycarbonate bulb - just punch a small dimple so there's a pip on the inside that holds into a groove in the bulb. You can see these in the photo of the disassembled lamp in my first post.

I'm thinking that a visit to the library when I'm next in town could be in order - and see if they have BS EN 60598 available to read

 

[plugwash]

I thought 24 volt was extra low voltage?

In IEC jargon as adopted by BS7671 yes.

But the IEC and BSI don't get to define regular English much as they may wish they did. Regular english is what it's users make of it and vauge terms like "low" and "high" must be treated as imprecise/unclear unless there is reference to a specific definition.

 

[bernardgreen]

In theory the rubber sleeve of the lamp holder should form a water resistant seal to the glass of the bulb hence the joint between the glass and the cap of the lamp is protected from water.

The village has over a thousand golf ball lights at Christmas

and this year the conversion from incandescant to LED has begun. Time will tell how many of the LED lamps fail due to moisture ingress.

 

[SimonH2]

Yes, the rubber sleeve should keep most of the water out. But when I've removed some of the bulbs ive found water trapped inside. The keynthing is that if the lamp is wet when air is drawn in then water will be drawn up into the seal.
As already mentioned, a 25W bulb will heatvthing up enough to drive out water. That's not going to happen with a 2W LED.
I've had some failed bulbs on a radiator for a few days - the IR between cap and terminals is now OK but I think there's still moisture to be driven out from the "cardboard" insulator.

 

[john4703]

Way back in the 1960s I was shown a lamp that had been removed form the Blackpool Illuminations, it was about half full of water. The questions we had to answer as tech college students was how did the water get in and how did the lamp keep working. The second was easy as the water level was below the filament when the lamp was hanging cap up. It was probably a 60w lamp so loads of heat but not enough to keep it dry.

 

[SimonH2]

I'd be interested in how on earth it kept working without a vacuum. If the water could leak in, the lamp clearly wasn't gas-tight - and my experience says that the filament very quickly turns to a white coating on the inside of the glass envelope when air gets in.

 

[john4703]

I'd be interested in how on earth it kept working without a vacuum. If the water could leak in, the lamp clearly wasn't gas-tight - and my experience says that the filament very quickly turns to a white coating on the inside of the glass envelope when air gets in.

If I could answer that I'd have got top marks in the course work. It does seem impossible but it did work as demonstrated when put into a lamp holder and switched on.