View Full Version : 230-240 volt electronic ballast: info & proper use

01-08-2009, 03:08 PM
I was hoping I can use a german electronic ballast for T5s, because they have models that can power four T5s at a time plus being dimmable, I think it is a wonderful product that is overlooked in the US. I am presuming i would need a transformer to wind it down to 120v. Where do I search for this? Next question would be ,I am wondering I recall transformers at 240 volts were more common in the US market some time ago, wondering if anyone can tell me what and why it is phasing out, besides the fact that you need another component which is the transformer. I would appreciate some tips from the pros out there.


01-08-2009, 05:47 PM
Unless the device is spec'ed at both 50/60Hz, forget it. Using a 50Hz device on 60Hz can create a lot of heat and destroy itself. Then, adding a transformer to get the proper voltage means an additional source of heat and another source of failure - the heat is wasted energy - no transformer is 100% efficient, some much more so than others.

01-09-2009, 12:48 AM
If it is rated for 60Hz, give it 240. Note that switches would have to be properly rated.

01-12-2009, 06:04 PM
If the 230-240v ballast has 50-60 hz, what do you mean, to "give" it 240v, please pardon my ignorance on this subject. So is it possible then for me to use a ballast with 240v if I use a 240v switch and where do I look for this? :confused:

Regarding heat as waste, I agree. In other words a transformer is not recommended. But then, when I see that there are ballast at 240v or 277v in the US, how does one go about that? :confused:

For lack of a better word, i am some artist, and i am building "this form" and i hope to install flourescent lamps in it with a ballast. For now, I have decided to use a Fulham 120v ballast, manufacturer confirmed I can have 4 flourescent lamps for this one ballast. I hope I am keeping it simple, for my lack of electrical knowledge.

But I greatly appreciate the responses of you both. :)

01-12-2009, 08:04 PM
IF the ballast is rated to work at both 50/60 Hz (it would say that), then, you could apply 240vac, 60Hz to it and it would work. Some electronics can handle various frequency inputs, some can't. This would require rewiring the circuit to get 240vac. Might be easy, might be tough.

01-12-2009, 10:25 PM
That is correct. Most US residential circuits are 120 V 60Hz. The service into the main panel is 240 V 60Hz. Some things in the house can require 240V. Things like electric stoves or dryers, well pumps. If you can get a properly installed 240V circuit installed between the main breaker panel (it will need two appropriately rated breakers) and to the light switch and light circuit you could use the light fixture that you have.

This is not something you ought to do yourself with your apparent level of knowledge about this stuff.

If there is no clear way to get at the necessary wires (probably the case) this would be pretty expensive to do. Even getting someone in to change the wires if access is easy may cost more than a new fixture.

So it is doable but probably not practical.

If you did try using a transformer to step up the voltage, you would have to find a place to mount it at the light or somewhere in the wiring between the switch and the light fixture. You can find a transformer online. Sites like Mouser or DigiKey. Or lots of surplus places. You can use an autotransformer rather that a regular step up transformer. One of those would be cheaper and maybe a bit lighter.

IF the unit is indeed marked as working at 60Hz. If that is not the case, none of this is certain to work. It could work, could do nothing or not much, could let the magic smoke out.

01-20-2009, 02:07 PM
I appreciate all the input from the last couple posts.

I tried contacting Digikey on the autotransformer and they couldn't place what I was looking for. Is there another way to call this or a specific part #or model . If I can find this in the market, it might be a cool solution........while crossing my fingers....:)

01-20-2009, 02:40 PM
You have never said if the unit is marked for 50/60 Hz operation. Tell us. Usually for anything with a transformer (ballast coil) if it works at 50 Hz it will at least not burn up at 60Hz. All electronic supplies tend to work at either because they rectify the AC input and use the resulting DC to run themselves; but not necessarily.

You want a 120V to 240V transformer with at least the VA (volt Amp) rating of the total of the lights you are going to put on the circuit. Incorrect but usable assumption is that watts = VA. Add maybe 20% to the watts to get VA.

Any transformer that meets these requirements will work. A regular transformer has two isolated windings; one for each voltage. An autotransformer has a single winding for 240V with a tap at 120V. This makes it cheaper. Either will suffice.

Search for "surplus transformer 120V 240V" and variations. Surplus dealers are a much cheaper source for just about anything. Pay attention to whether the contacts on the transformer are exposed if you are not planning on mounting it in some protected place. Don't screw around with these things unless you are OK with breaking something and smart enough not to kill yourself. Remember the Darwin Awards has openings.

01-21-2009, 04:50 PM
You want a 120V to 240V transformer with at least the VA (volt Amp) rating of the total of the lights you are going to put on the circuit. Incorrect but usable assumption is that watts = VA. Add maybe 20% to the watts to get VA.

AKA a step up transformer. Using that term may help you find one.

For a previous job I had, we used to keep a number of step up transformers around for powering equipment that we were selling overseas. Looks like Radio Shack has one:

01-21-2009, 05:54 PM
IF the system will work at 60Hz, then just wire it up to use 220/240 from your panel. Forget the transformers, which will add cost, heat, and complexity. Depending on the current required, they can be big, too...finding a place to mount it safely and within codes could be a problem. IF they aren't spec'ed for 60Hz, forget about it and don't waste your time.

01-22-2009, 02:07 PM
Yes, but note that getting the 240V from the panel to the lights may be a serious exercise. If an electrician becomes involved for routing a new 240V circuit, the transformer alternative would be paid for some time in the first billable hour.

I just happened to have a Jameco catalog at my TV chair last night. Page 118 of catalog 291 - part # 85016. 300 VA 34.95. An example. Primary and secondary do not matter. Transformers are essentially symmetric devices.

There are lots of places that sell suitable transformers. It is left as an exercise to the purchaser to find them.

01-23-2009, 05:57 AM
410.6 Listing Required.
All luminaires and lampholders shall be listed.

You can't build you own light fixture it must come as a listed assembly

01-23-2009, 09:07 AM
A point the OP made above and I also lost sight of during the discussion - it is an art object of some sort. Safety must apply but I suspect the luminaries and lamp holders part probably won't work out in a custom use.

A bit of further info that may help avoid some frustration. The big white metal pieces that form the top of a fluorescent lamp assembly is not just for reflecting. It also provides a necessary ground plane for the lamps.

01-31-2009, 07:45 PM
If this is a residence, voltages higher then 120 volts are prohibited. See 210.6 (A) 2005 NEC.