In Us Can I Use A 120v Bulb In Tradeshow Display From Thailand?

[t.s]

i have a tradeshow display we want to take to the US, my question is can we use the typical 240v hardware from here in the states and just change to 120v bulbs purchased there?

The bulbs are just typical 60 or 100 watt incandescant.

are the tolerances of the cord and fixture significantly different?

[InterestedObserver]

My initial reaction is to say that nothing built and wired in Thailand to Thai standards will meet the US National Electrical Code (NEC). There are numerous threads posted on ThaiVisa about the lack of proper grounding used in Thai wiring. Any US electrical or fire inspector would collapse in a fit of laughter. If you did manage to get the display approved you could use 120 volt incandescent bulbs in the compatible 240 (220) volt sockets. Pay attention to the wattage ratings so you do not generate too much heat and start a fire!

[elkangorito]

InterestedObserver has said it all & you be crazy not to follow his advice in this matter.

[Tywais]

Pay attention to the wattage ratings so you do not generate too much heat and start a fire!

However in this instance, the wattage rating is not as significant an issue as the current rating of the sockets, switch and lamp wiring. Running the same wattage rated 110V bulb will draw twice the current as a 220V rated lamp of the same power and can exceed the current ratings of the socket or switch or wiring which is also a potential fire hazard due to component overheating.

[IMA_FARANG]

Sorry but there is some misinformation in a few of the posts here.

I've done it and.....

Using a 120 volt bulb in 240 volt system will make the bulb burn much more brightly. It will either burn out like a flashbulb, or just shine very brightly.

Using a 240 volt bulb in a 120 volt system will make it burn less brightly. It won't seem as bright.

For most 120 volt bulbs it will not draw enough current in a 240 volt system to cause a problem with the wiring. If it does the incasdesant filament in the bulb will burn out before the wiring goes. Possibly in an extreme case a breaker would trip...but usually the bulb just burns out.

Assuming the incadesant bulb doesn't burn out immediately....be prepared to change the bulbs more than usual....they burn out quickly.

But all bets are off if you try to use those plug-in flouresent lamps that fit into a regular incadesant lamp socket. Don't try that.

[Tywais]

Sorry but there is some misinformation in a few of the posts here.

I wasn't referring to mixing bulbs with different voltage ratings between two systems (110/220) but that a bulb with a correct voltage rating for the system and has the same power rating will use twice/half the current in that system. I realize I didn't word my previous post well so an example is easier: A 110W 110V bulb will be exactly 1A but a 110W 220V bulb will draw only .5A. In other words, for the same power rating there will be twice the current drawn in the 110V system as the the 220V systems with appropriate matched voltage ratings lamps.

The question by the OP relates to the fixtures/switches/wires of his lighting system and what effect 110V lamps with the same power rating will have on it (at least how I am interpreting it).

[elkangorito]

Original post,

i have a tradeshow display we want to take to the US, my question is can we use the typical 240v hardware from here in the states and just change to 120v bulbs purchased there?

The bulbs are just typical 60 or 100 watt incandescant.

are the tolerances of the cord and fixture significantly different?

It's not only the lamps (bulbs) that need to be considered. Most cable used in Thailand for domestic installations is only rated at 300 volts. This may contravene the requirements of the NEC & therefore present an electrical hazard. If a problem should occur, American insurance may refuse to pay. Also, prosecution may ensue.

Most cables are rated according to the voltage to which they can be exposed. For example, a single phase cable (220v) located amongst some 3 phase cables (380v). In this case, ALL cables must be rated to accommodate 380 volts. In other countries, most cables are rated to 600v minimum...but not in Thailand.

It's all about insulation.

Edited December 4, 2009 by elkangorito

[InterestedObserver]

Pay attention to the wattage ratings so you do not generate too much heat and start a fire!

However in this instance, the wattage rating is not as significant an issue as the current rating of the sockets, switch and lamp wiring. Running the same wattage rated 110V bulb will draw twice the current as a 220V rated lamp of the same power and can exceed the current ratings of the socket or switch or wiring which is also a potential fire hazard due to component overheating.

The electrical and/or fire inspector would not approve the display unless all the fixtures met UL, CSA or IEC standards; the white, black and green wires were all in place and properly connected; and the display met the appropriate articles of the NEC. If any of the above did not meet the requirements for the wattage/voltage bulbs being used, the display would not be approved for use.

[lopburi3]

Use of higher voltage allows the use of smaller wire. As you lower the voltage you require larger wire to carry the same amount of power. So when you drop from 240v to 120v you need much larger wire.

[longball53098]

In my past life I have been to at least 3 or 4 trade shows in the US. I had to support the products we manufactured and were showing. All of the equipment we displayed used power as well as the display booth. In a few cases we had to have specific work done to get plugs where we wanted them and we had to call in the show electricians to run any and all wires cables and power strips. If it was not attached to a manufactured display unit the trade show sparkies had to do it and you paid the bill for what they did.

In all shows I have been to and the ones my colleagues have been to there was never any sort of inspection of the displays or the electrical equipment.

Take you're display and make sure its safe and use it. For all I know there is a provision written in to the NEC that deals with these cases and using foreign equipment.

[InterestedObserver]

In all shows I have been to and the ones my colleagues have been to there was never any sort of inspection of the displays or the electrical equipment.

And you purchased your insurance liability coverage for your foreign equipment (display) where?

[longball53098]

I would bet the folks that sign the contract for the show booth space don't read the fine print about if a electrical fire or some other sort of accident happens who pays. Most likely the renter of that booth is on the hook not the convention center or the sponsor of the event. I can guarantee that the sh*t flows down hill and you are at the bottom if you did not CYA.

Make sure you're stuff is up to the safety regs needed for the place.

[Beardog]

Just switch the bulbs to incandecants using 220. I blew up a 8 watt American bulb(110) in 20 minutes. It was 2 times brighter before it poofed. The 220 version puts out less light but works on 220 volts.