Using 220-240v Bulbs In 110v Lamp?

[wpcoe]

Thanks for the comments, elkangorito. I had no idea there were electronic transformers.

I just had an architect/interior designer over yesterday to give me an estimate. He was trying to convince me to install a kind of shelf/ledge 30cm from the ceiling with the lights reflecting upward, rather than boxing in an enclosed 30cm x 30cm space with the lights facing downward like I had planned. I wasn't keen on his suggestion, but now that I think about the heat, especially in light of your comments, his plan may be SAFER!

It was interesting talking with him. He's Thai and has done some rather expensive projects, including his pride and joy: a currently under construction development of B20million+ houses in NaJomtien. I had to keep reminding him that he & I were talking about a slightly frumpy 15 year old condo that was in an entirely different league. No need for fancy dimmer switches, carved teak moldings and marble floors. :-)

[chownah]

wpcoe,

What you've describe is called indirect lighting and is very nice. You can do the same thing by putting sconces on the walls and eliminate the expense of building the shelf....or maybe put up tracks for track lighting and do it that way and also have the benefit of being able to change the lighting around if you rearrange your furniture.

Chownah

[Crossy]

Thanks for the comments, elkangorito. I had no idea there were electronic transformers.

When you get your electronic transformers make sure they are marked as 'dimmable' (assuming you'll be wanting to dim the lights) standard units tend to go pop if you try to use a dimmer.

Also consider LED lamps, they plug into the same holders and use the same power supply as the halogens but run almost cold. Unfortunately not quite as bright as halogens and considerably more expensive (have almost infinite life though).

[dhrobertson]

Most serious issue regarding table or floor lights in Thailand is that polarity is not forced at the plug. These sort of lights typically have a single pole switch and it is therefore possible for the switch to be in the neutral as opposed to the phase. This results in a situation where you think the light is switched off but in fact the bulb holder is still live. many people have received severe shocks whilst changing bulbs because of this. Edison screw connections should have phase connected to the centre pin. Here in Thailand you have a 50% chance of phase being connected to the outer screw thread. I recommend marking the plug to ensure correct polarity or if you have three pin sockets use a three pin plug to force correct polarity.

I think it highly unlikely that there will bve an issue with the switch rating on a 110V light used in a 220V environment. The current for a 100W 220V incandescent is only about half an amp.

Most lights will have a maximum power rating, say 60W or 100W. It makes no difference about the voltage, just watch the wattage.

Concerning halogen spots. It is possible to get 220V or 12V versions. There is more variety with the 12V type but both are dimmable. The lamps run very hot and care should be taken to ensure sufficient ventialtion at the rear of the lamp. Heat is not a problem with the transformer assuming you use qualtiy gear. With regard to transformers, both rwgular and electronic transformers can be dimmed. I recommend using standard transformers as they introduce less harmonics into the system. Try to use transformers with a good power factor (0.85 or better).

A key benefit of 12V halogens is that they can be considered SELV (separated extra low voltage). That means they can be used in situations such as bathrooms where 220V lamps would be hazardous.

Once again we get the topic of the neutral line in Thailand. The star point of a 3 phase transformer is connected to neutral and bonded to ground. Single phase transformers have one side of the secondary winding bonded to ground. This neutral (PEN) line is also bonded to ground at intervals before it reaches your installation. In the absence of a fault, neutral is always at close to 0V. I recommend connecting the ground and neutral buses at the origin of the installation. I also recommend adding a supplementary ground electrode connected to the neutral bus with cable not less than 50% of the size of the main feeds.

[dhrobertson]

The use of DC with Halogen lamps will decrease the life of the lamp.

So how do they manage with Halogen lamps in car headlights?

That is definitely DC.

A bloody good come-back Astral but it is easy to answer.

The halogen lights/lamps used in motor vehicles are quite different to those used in the home. The filaments are much thicker (usually a dual layer winding up to 3mm thick) than those found in the "home" version, which is why they are very reliable (& expensive). Also, the quartz envelope is physically bigger than that found in the "home" version, which allows for better heat dissipation. The price of an automotive lamp reflects its reliability.

Generally, using DC to supply ordinary incandescent lamps will lengthen the life of the lamps (marginally) but the light output decreases rather rapidly. There are grounds for believing that DC may assist in the removal of filament material by electro-deposition, as well as evaporation. These actions will ultimately blacken the inside of the glass envelope.

Also attached, Rev 1 of the domestic lighting paper.

Just read your nice piece on domestic Lighting. A couple of areas you might want to consider addressing:

1) Minifluorescents are not quite so environmentally as you think unless you add PF capacitors.

2) Necessity of SELV lighting in bathrooms etc

3) The hazards of extrior landscape lights. Use SELV or ClassII or fit ELCB(RCBO)

[elkangorito]

Just read your nice piece on domestic Lighting. A couple of areas you might want to consider addressing:

1) Minifluorescents are not quite so environmentally as you think unless you add PF capacitors.

2) Necessity of SELV lighting in bathrooms etc

3) The hazards of extrior landscape lights. Use SELV or ClassII or fit ELCB(RCBO)

I get your drift & thanks for your comments.

Re;

1) Not worth mentioning PF unless a large number of these lights are going to be used in any 1 installation, which is not likely to occur in a domestic installation.

2) Good point. I was remiss in mentioning this.

3) Another good point. Perhaps a discussion on ELV devices needs to happen. For me, this falls under the banner of "Hazardous environment/locations".

THanks again.

[wpcoe]

Also consider LED lamps, they plug into the same holders and use the same power supply as the halogens but run almost cold. Unfortunately not quite as bright as halogens and considerably more expensive (have almost infinite life though).

I've never seen LED lamps in Thailand. Where are they sold?

[Crossy]

Also consider LED lamps, they plug into the same holders and use the same power supply as the halogens but run almost cold. Unfortunately not quite as bright as halogens and considerably more expensive (have almost infinite life though).

I've never seen LED lamps in Thailand. Where are they sold?

Good question

I've seen them INSTALLED in Central chit lom.

Not actually looked for them but I'd suggest Homepro as a starting point, they are getting an increasing number of more exotic electrical items. I'll have a butcher's next time I'm in one

[dhrobertson]

Just read your nice piece on domestic Lighting. A couple of areas you might want to consider addressing:

1) Minifluorescents are not quite so environmentally as you think unless you add PF capacitors.

2) Necessity of SELV lighting in bathrooms etc

3) The hazards of extrior landscape lights. Use SELV or ClassII or fit ELCB(RCBO)

I get your drift & thanks for your comments.

Re;

1) Not worth mentioning PF unless a large number of these lights are going to be used in any 1 installation, which is not likely to occur in a domestic installation.

2) Good point. I was remiss in mentioning this.

3) Another good point. Perhaps a discussion on ELV devices needs to happen. For me, this falls under the banner of "Hazardous environment/locations".

THanks again.

Yeah, I fully agree that PF correction is not really worthwhile for small installations. Having said that, many environmentally conscious people are switching from incandescent to compact fluorescents because they consume less power per lumen and put less strain on generating capacity and hence contribute to less pollution. All well and good but of course the marketing people over egg the benefits. I have in front of me right now a 5W compact fluorescent with an E27 base. The box tells me that by using this I save 80% energy. Really? I see on the base that the current drain is 45mA. Now 5W at 220V should be 23mA. This tells me that the power factor is about 0.5. In terms of savings in generating capacity, switching from incandescent to compact fluorescent saves 60% not 80%. The full savings can be achieved by adding a capacitor at very little extra cost. In the UK, part P of the building regs requires 40% of luminaires in new buildings to be compact fluorescent which is sensible. So, yes I fully agree that it's not worth the effort for single lamps. However for people with bars or hotels, it would be worthwhile adding a single capacitor per lighting circuit. I attach a spreadsheet for capacitor selection. You can choose your target PF. The algorithm is mine but anyone can use it. I take no responsibility for errors however.OK I'm blathering on now! Time to shut up and get a beer!

powerfactorcorrectioncapacitorsupdate1.xls

[chownah]

Please don't post in green....I can't read it. Black is best.

Chownah

P.S. I looked at your spreadsheet and I accidentally changed it. I was surprised that when I closed and chose to not save my changes that when I re-opened it, it appears that I infact did change it...so I think I put it back the way it was....maybe you should check it to be sure....also it would probably be best if you locked it....Sorry, Chownah

[h90]

Aside from lamps that contain transformers (like backflip mentioned) it seems to me that most lamps are rated for watts and not volts....if you don't exceed the wattage then I think you'll be ok.

Chownah

If it is a filament (incadescent) light bulb it will use four times the wattage at twice the voltage. So if it is a 100W 110V bulb used with 220V it will use 400Watts. It will be bright and it's life time will be shortened considerably.

would say the lifetime will be shortend to minutes at maximum

There was some rough estimation from arround 2nd worldwar but still valid.

Something like 10 % more voltage: double light half lifetime (I am not sure about it exactly but something like that).

Tywais: 400 Watt is exactly true (just calculated it myself because did not trust you )

[Tywais]

Tywais: 400 Watt is exactly true (just calculated it myself because did not trust you )

Being an electrical engineer myself, I do rely upon cross checks.

[elkangorito]

Aside from lamps that contain transformers (like backflip mentioned) it seems to me that most lamps are rated for watts and not volts....if you don't exceed the wattage then I think you'll be ok.

Chownah

If it is a filament (incadescent) light bulb it will use four times the wattage at twice the voltage. So if it is a 100W 110V bulb used with 220V it will use 400Watts. It will be bright and it's life time will be shortened considerably.

would say the lifetime will be shortend to minutes at maximum

There was some rough estimation from arround 2nd worldwar but still valid.

Something like 10 % more voltage: double light half lifetime (I am not sure about it exactly but something like that).

Tywais: 400 Watt is exactly true (just calculated it myself because did not trust you )

As a general rule, a 4-5% increase in voltage, above its design voltage, will reduce the life of an incandescent lamp by about 50%.

[elkangorito]

My comments in blue.

Yeah, I fully agree that PF correction is not really worthwhile for small installations. Having said that, many environmentally conscious people are switching from incandescent to compact fluorescents because they consume less power per lumen and put less strain on generating capacity and hence contribute to less pollution. All well and good but of course the marketing people over egg the benefits. I have in front of me right now a 5W compact fluorescent with an E27 base. The box tells me that by using this I save 80% energy. Really? I see on the base that the current drain is 45mA. Now 5W at 220V should be 23mA. This tells me that the power factor is about 0.5. In terms of savings in generating capacity, switching from incandescent to compact fluorescent saves 60% not 80%. The full savings can be achieved by adding a capacitor at very little extra cost. In the UK, part P of the building regs requires 40% of luminaires in new buildings to be compact fluorescent which is sensible. So, yes I fully agree that it's not worth the effort for single lamps. However for people with bars or hotels, it would be worthwhile adding a single capacitor per lighting circuit. In the case of large commercial/industrial installations, it is not cost effective to add individual PF correction to each device. Usually, a PF correction unit is installed at the Main Switchboard (incoming supply). I attach a spreadsheet for capacitor selection. You can choose your target PF. The algorithm is mine but anyone can use it. I take no responsibility for errors however. It is not clear to me what information the spreadsheet is supplying. PF correction is selected by correcting from a known "low" PF to a desired "higher" PF. From the spreadsheet & in the example of an 8 Watt load, your spread sheet indicates a capacitance of 0.0198 micro Farads for a PF of 0.9. From what lower PF are you correcting to the value of 0.9 to obtain this capacitance? From my calculations, correcting a PF of 0.5 on a 220 volt 45mA load, to a PF of 0.9 will require a capacitance of about 0.6 micro farads. In other words, the existing power factor must be known & then used in the calculation in order to calculate the required capacitance of the desired PF. Also, over correction (too much capacitance) will have the same detrimental effect as that of an inductive load. Another problem is that when incorrectly sized capacitors are used for starting motors (large & small motors) or for PF correction, resonance can cause high circulating currects (parallel) & dangerously high voltages (series). I therefore think that adding capacitors to loads should not be done unless the sizes have been calculated correctly. OK I'm blathering on now! Time to shut up and get a beer!