Max LED wattage for a fixture

[ericmark]

Parlance correction, Lesson 1

Bulb

Lamp

Luminaire

Aide memoire: Bulbs grow, lamps glow

Histrionically this is incorrect, on the wall or front of car we have a spigot, on to this we fit the lamp, inside the lamp we could has a wick (oil) mantel (gas) or an element (electric) the latter is normally contained within a bulbous envelope of glass, or a bulb for short, there are exceptions, we also had tubes, so whole assembly is called a lamp, if you ask for a headlamp you will get the reflector and glass, but no bulb.

Today it is a bit of a problem, as the renewable item is often not bulbous, a coiled tube for example, and also the renewable item often contains more than the light emitting unit, it is common for ballasts, or drivers to be built inside the renewable unit, however the lighting trade tends to hang onto a name even when the name no longer describes what it is, so when the ballast is replaced with electronic components it is still called an electronic ballast, and a transformer again when replaced with electronic components is called an electronic transformer, and a device used to reduce the voltage for LED lamps is still called a driver even when it controls voltage not current, so in keeping with this trend, we still call the renewable part a bulb, when it replaces the bulbous part of yesteryear.

English is interesting in the way words have changed meanings, in this case the auto electrical trade have called a bulb a bulb all the way through, but the low voltage electrician has for years have spouted on how bulbs come from the garden, however they have failed to find a replacement word, Fitting, Luminaire, and Lamp, all refer to the whole unit.

The question on bulb size is interesting as well, it is all down to heat, so if we look at a gas or oil lamp, if it was to burn the fuel at a rate of 60 Joules per second likely the temperature would be far higher than a tungsten bulb burning the same amount of fuel, as the tungsten bulb emits more light, however if light is absorbed into a surface it is turned into heat, this is why we open and draw curtains over our windows, to stop or allow heat and light to enter or leave the house, so if you could get a 100W LED bulb as long as the light could pass through the shade it would run cooler than a 60W tungsten, so the limit for LED lamps would normally be higher than with a tungsten.

However I have stipulated a shade where the light can pass through it, if the shade defuses the light and does on allow all light to pass through it, then it could heat up the shade more with 60W of LED light than tungsten light as more light is being converted into heat. In real terms you can't get 60W LED bulbs so the problem does not arise.

Oddly I have returned to using a spigot in my mothers house, well modern equivalent to it, I can slide out the chandelier and replace any parts i.e. bulbs, then once all done, slide the hook, chain, and chandelier back in place, not that I do that, it is so I could fit rose to ceiling without needed to hold the weight then I had to support weight for very short time as the whole fitting is slid into place.

On my push bike I still have a spigot on the handle bars and a lamp which I slide into place as and when required. These

are lamps, the bulb if there is one, would fit inside them. In case shown it was a simple flame, no wick, or mantel.

 

[ban-all-sheds]

I visited a Victorian NT property a couple of weeks ago which still has working gas lights.

 

[SUNRAY]

Parlance correction, Lesson 1

Bulb

Lamp

Luminaire

Aide memoire: Bulbs grow, lamps glow

Do you know what?

I knew those b@st@r@s miss sold me, I purchased some bulbs and planted them but the bl@@dy things never did grow

Never worked as fork andles eiver.


Tell me something. Who, and when, decided that bulbs should be called lamps and lamps should be called luminaires?

 

[ban-all-sheds]

Why does it matter?

 

[SUNRAY]

Why does it matter?

Only if there is a dispute. For example: within a contract to supply lamps.

 

[SUNRAY]

And the only dazzling display in the garden these were capable of involved some of that fangled lectrickery stuff.

 

[ban-all-sheds]

Only if there is a dispute. For example: within a contract to supply lamps.

Only idiots would let that become a dispute.

 

[SUNRAY]

Only idiots would let that become a dispute.

I've known far too many similarly minor things develop into big issues.

I once ordered 20 pop shields for tie clip microphones, value maybe a pound each. What turned up was 20 radio mic body packs at around £100 each, they then demanded a 20% restocking fee. That solicitors letter was worth every penny.

 

[FrodoOne]

The issue is that LED lamps are extremely intolerant of the heat that they produce, and higher power ones produce enough heat that getting rid of it can be a problem. A luminaire may well be able to tolerate the heat that a 60W incandescent generates, and therefore have no problems at all with the heat that a 60W LED generates (which would be less), but may be totally unable to keep the LED lamp cool enough.

In relation to this comment, I recommend reading the section "CFLs in Existing Luminaires" about half-way down this document. http://sound.whsites.net/articles/incandescent.htm

While the writer was discussing CFLs, much the same comments apply to LEDs.

 

[stillp]

the bl@@dy things never did grow

I bet those caps didn't fit you either.

 

[ericmark]

In relation to this comment, I recommend reading the section "CFLs in Existing Luminaires" about half-way down this document. http://sound.whsites.net/articles/incandescent.htm

While the writer was discussing CFLs, much the same comments apply to LEDs.

He does make a good point about cooling, we look at GU10 LED lamps with huge cooling fins, clearly the temperature must be much lower for the diode to survive. So may be shades should be marked as suitable for LED lamps? or of course not suitable.

Oddly I have noted one huge advantage with LED, the ceiling above them does not discolour, with the old tungsten they caused a draft, the chimney effect, air circulated both keeping them cool and causing dust laden air to brush past the ceiling so over time above each lamp we got a dark patch, there is not enough draft caused by LED bulbs to cause this, also LED bulbs tend to send no light in the direction of the bulb holder, so pointing up and pointing down can make a huge difference. Pointing up to a white ceiling works well, the light is spread and defused by the ceiling, however if the ceiling is not white then we have a problem.

 

[SUNRAY]

I bet those caps didn't fit you either.

You're right, left a ruddy great mark on my forehead

 

[junebug29]

Ok. Thanks all.

One more question. I remember a few years ago I was told you couldn't put an led dimmable into a normal luminaire. I have kitchen dimmable downlights currently with halogens. Can I put dimmable leds there.

 

[winston1]

Ok. Thanks all.

One more question. I remember a few years ago I was told you couldn't put an led dimmable into a normal luminaire. I have kitchen dimmable downlights currently with halogens. Can I put dimmable leds there.

You can put then in but they probably won't work with the existing dimmer.

Why on earth do you want to dim lights in a kitchen? It is a work room and you need as much light as possible.

 

[junebug29]

This is what I was told a few years ago but then someone told me that modern LEDs will work with old halogen dimmers.

As for dining in the kitchen, it's great for mood lighting. When cooking they are on full blast but when eating we dim them.