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In ongoing attempts to reduce power-requirements, energy costs and eye-strain I've decided to replace a fluorescent daylight lamp and instead fix up an old desk lamp with an LED bulb.
So I got an old 1970s lamp from Ebay. It already has a bayonet-fitting LED bulb, assumedly retrofitted by previous owner. On first using the light I noticed after 30 mins (or possibly less) this LED bulb gets quite warm/hot around the white plastic collar. Not so hot as you'd drop it, but hot enough to make me wonder. My knowledge of electrickery is somewhat on par with Catweazel so any advice above that would be gratefully accepted!
Wot it is:
1970s Anglepoise Model 90 desk lamp
Factory label inside shade states '60W max'
Bayonet fitting
Older style UK plug fitted with 3A fuse (inside plug it lists canles as 'black' and 'red', assume this is the 1970s plug.
Blue and brown live and neutral cables currently installed in plug (so light has been recabled in recent years?), cinched up, contacts seem ok on casual inspection. No separate earth cable.
Currently fitted bulb:
7W LED (non dim)
46mA
470lm 3000k
Now, a similar prob exists with the new 9.5w 83mA LED bulb I fitted on the ceiling light a few weeks ago. That too gets really hot around the dense matte white plastic collar (the part with all the details printed on), but (same as the other bulb) not hot on the frosted globe of the bulb itself. Ideally I want to use the same 9.5w bulb in the Anglepoise also, to achieve a uniform 6400k spectrum/temperature to work with, either at desk and/or with the ceiling light.
Am being alarmist? Is it normal for LED bulbs to run this hot under the collar?
You are being alarmist. Put a 60w halogen lamp (not bulb) in it, then feel how hot the surround is then.
The LED is using 7 watts, even if all of that wattage was turned into heat (it isnt), then it would still be less heat than a filament lamp puts out. LEDS are typically 80%+ efficient, filaments sometimes get 30%. The rest is turned into heat. So a 60w filament is putting out 40 watts+ of heat.
There is the slight problem of localised heating from the LED, they should have a decent heatsink on their back, but, even so, they run cooler than filament lamos.
Malvern Rider. You need to put an earth on that.
Old Anglepoise lights are made of metal....bit conductive if there is a fault.
Sticking an LED in can’t cause any issues compared to old style incandescent bulbs, for reasons mentioned above. LED’s can run pretty hot, a high powered flashlight can get pretty warm, even with a 3.7v 18530 cell, but compared to how hot an incandescent bulb can get, even 12v halogen bulbs can get blisteringly hot.
A 1970’s Anglepoise will be fine, it’s an ideal lamp to use with an LED bulb replacement. I’ve got a dinky little Anglepoise copy that I put a warm white LED into and it’s just like an incandescent, but a bit more focused.
You are being alarmist
Music to ears. Thanks! But...
you need to put an earth on that. Old Anglepoise lights are made of metal...
Argh. So, am assuming a complete rewire? Where to earth it? Not even sure I could fit 3-core flex through the (thin) arms of the lamp...
Most consumer items are either Class 1 or 2 electrically, Class 1 has an earth, Class 2 doesnt, as it will have double, or reinforced insulation in the items body. There are many things which are all metal, but are class 2 - no earth.
Older items are not as safe as things nowadays. Adding an earth may not be required if it has the 'square within a square marking' or any other Class 2 markings on the base. If you have RCD protection for the socket you are plugging it into, then I would carry on using it, if it does ever develop a fault, then the RCD will trip pretty quickly (quicker than a fuse, by a long way).
I'm currently using a 40w incandescent bulb fitted to a 1960's Soltan heat lamp like this to heat my desk. It's a great source of radiant heat and keeps my hands warm on days when it's not quite cold enough to put the heating on 🙂
I'd not worry.
alanl - thats useful info
It has this label in the lampshade, but no markings I can see on the base, just green baize. Assuming the label is original then seems like all is well? We have fixed RCD on the circuit which supplies the socket. Irun a four way strip from the socket and the lamp plugs in to this.
wwaswas that's a good idea. I generally use no heating in the workshop other than the odd trump or some hand-sanding.
Most anglepoise lamps aren't earthed, they just use double insulated cables which avoids the need for an earth to the metal body.
that little Square in a Square logo on your label there shows the cables are double insulated.
The other triangle thing with lightning bolts is to warn you that god is angry. Or 'slippery road'. I forget which
that little Square in a Square logo on your label there shows the cables are double insulated
ooh, stuff keeps cropping up, need closure. So as it's a vintage light (circa 1970-1980) and the wiring currently fitted is blue and brown 2-core flex (black, flattish cable) - then how (other than employing a qualified sparky) to know if the cables are now 'double-insulated'?
(Getting a bit tired of God/s being angry, they seem so petty and easily triggered for such megalomaniac setup artistes..so hope it's merely a skid warning!)
So as it’s a vintage light (circa 1970-1980)
Oi. I resent things younger than me being described as 'vintage'. I still have some of my own hair and teeth. Somewhere.
In something like a table lamp double insulation can mean things like... the lamp holder itself being plastic rather than metal and on something that articulates like an angle poise it might be something like little rubber/plastic collets where the cable might rub.
However its achieved if in doubt (ie if theres no marking otherwise) you need to assume its Class 1 (and needing an earth) but if its marked as Class 2 / Double Insulated then it is.
Thats only assurance that its been correctly manufactured though. But theres only two functional elements - the bulb holder and the switch - if they are in good condition and not metal then the only other variable is the cable and the cable is only vulnerable at the places where it moves or goes round tight bends, so if they all look good then its probably good
EDIT - sorry in my previous post I said the symbol meant the cables were double insulated - what I meant was it means the appliance is double insulated.
So as it’s a vintage light (circa 1970-1980) and the wiring currently fitted is blue and brown 2-core flex (black, flattish cable) – then how (other than employing a qualified sparky) to know if the cables are now ‘double-insulated’?
At all points the live cores are covered by two layers: an outer layer of insulation (black) and each core has an inner (blue / brown) .
In a slight thread hijack - is that a regulation definition of double insulated footflaps?
Asking because a friend makes lamps out of copper tube and uses double insulated bulb holders with modern twin core pvc insulated and sheathed cable.
On the original point, it's entirely possible that modern LEDs push all their waste heat through the metal end cap whereas a filament bulb would heat the envelope, resulting in a hotter end cap.
In a slight thread hijack – is that a regulation definition of double insulated footflaps?
You'd have to find the relevant BSI spec. I assume you'd need two layers of insulation / plastic around the bulb mount as well.
A quick google suggests: https://shop.bsigroup.com/ProductDetail/?pid=000000000030208600