Hi,

2 years ago I moved from Holland to Canada. Last year I started collecting
old fashion light fixtures from Holland. Some were a pain to get shipped.
My latest fixture is a 1977 Philips SGS 201. I bought it from a Dutch guy and it came
with a 400 W HPL bulb. Since Europe is running on 220 Volts, and North America on 120 Volts, I was wondering the following:

The ballast in this fixture is not dual voltage. But what if I buy one of those power converters (from 120 to 220 V) and power up my ballast that way, am I able to light up my 400 watt bulb? Of course would probably need to figure out how much the power converter can handle, but lets say it would handle about 500 watts, will my theory work?

Replies to this post would be greatly appreciated!

- Jeroen -

It is not as simple, as all magnetic ballasts are sensitive to frequency. For 230V/50Hz practically all ballasts are series choke type with a capacitor connected parallel to the mains input for power factor correction. This mean, they will deliver ~20%less of current to the lamp, then rated. To keep it correct, you might compensate it by increasing the supply voltage (changing the frequency would be very difficult task).
As most of mercury lamps are 120..140V, on the choke is about 180V. To have the same current at 60Hz, the voltage across the choke should be 216V. And adding a lamp drop (be careful, due to phase-shift you need to use  Pythagoras...), you get supply voltage about 260V/60Hz. For this, you should replace the compensation capacitor for one designed to at least 280VAC/60Hz and reduce the capacitance by ~40%

Thanks for your info.

I understand the most part of it.

If most mercury lamps are 120v-140 v, would I just be able to hook up a North American 120_140 ballast (replace the European one) and have the bulb work on that?

Also, if I do decide to get a North American bulb (E39 base size) will I be able to use this in a E40 base sized holder, or is this gonna cause problems? I know that a E26 lamp fits a E27 base.

Using 120V/60Hz ballast would be the easiest, but if you find them - sale of new ballasts is forbidden in US, but i don't know about Canada...
What i'm not sure is the lamp lifetime and performance of EU lamp on US ballast - serial reactor ballast (the EU style) has lower current crest factor then typical American CWA, while higher crest factor causes larger stress on electrodes. Running US lamps on CWA is for sure OK, as they are primarily designed for it, but EU lamps are designed for serial reactor. And if you ever noticed in lamp catalogs, lamps for EU market offer higher efficacy then those for US market. The question is, why the difference: Or US lamps are only tuned for longer life and sacrifice the efficacy a bit (in EU the historically higher electricity costs ask for higher efficacies, while shorter distances everywhere allow more frequent relamping, so shorter life), or it is the pay for robustness to higher crest factor, or direct result of the higher crest factor on the same lamp...

And according to my experience US E26 fit into EU E27, as well as E39 lamp into E40 socket, but in reverse i'm not as sure. Better keep EU sockets with you...

Thanks so much again for your explanation.

I looked up the specs for my bulb and takes 140 V input so I could just go and find a
North American ballast for my lamp I guess.

Not sure what you mean by sale of new ballasts is forbidden in the US? As far as I know here in Canada it's not. I bought a MH bulb + new ansi ballast brand new.
I wonder why it is forbidden in the US?

Not exactly sales, but manufacture and/or import of MV ballasts (ANSI Hxx). Stocked units might be still offered, but they are nearly sold off.
Now there is in discussios (and in some states already in force) similar ban for probe-start MH ballasts.
But all this is about US, Canada i don't know...

wow I didn't know that.