Metal Halide lamp compatibiliy

[rgrgrgr]

I need to replace a Metal Halide lamp in a light fitting. The bulb is marked: SYLVANIA METALARC HSI-TD 150W/NDL UV-STOP. It's about 130mm long.

None of the Internet retailers I already have an account with stock this exact lamp, so I'm trying to figure out what other lamps might be compatible. Does anyone know if one of these would work?

compatible but this lamp specifies a 90V supply - does the light fitting contain a transformer?)

compatible, but claims to be 180mm long - a typo?)

[Adam Aglionby]

crossposted to sci.engr.lighting

Sylvania is mainly U.S. brand of Osram, 90V will be taken care of by the ballast , not a transformer possibly still big lump of iron in fitting.

Looks like a fairly standard 150W single ended tubular lamp, depends if you need a very specific colour.

Adam

[mroberds]

Googling this marking yields

, which says your lamp is

150 W, 95 V, 1.8 A, Rx7s base, 137 mm long x 24 mm diameter, clear glass, 4200 K color temperature, 13,000 lumens.

good newsreader it isn't), but doing a search at Farnell shows that Farnell stock numbers 1528728 (current stock) or 3415880 (limited to stock on hand) will probably replace the lamp you have.

Stock numbers 1528727 (current) or 3415879 (limited) will also work, but the light color will be a little different - these are "warm white" and more yellow than the lamp you have now. The difference is the color temperature - the number that's usually a few thousand degrees Kelvin. The lamp you have now is rated 4200 K and these two are rated 3000 K. As a comparison, a standard incandescent lamp will be something like

2700-2900 K. All of these lamps sell for about £17 at Farnell, which seems a little high.

Yes. There is a ballast that limits the current (and hence voltage) to the lamp.

It's a complete typo; it also claims to be 158 mm diameter, which it clearly isn't. This lamp at £10, or Screwfix 47458 at £20, both would seem to be a good match.

RS stock number 569-644 at £17 also seems to be a good match.

I'm pretty sure I've seen lamps like this on the shelf at general home-improvement retailers like Lowe's and Home Depot (in the US). Homebase is probably the equivalent store in the UK. They don't list such a lamp on their site, but (in the US) these stores only show a fraction of their stock on their Web sites, so they may well have it in the store. Take the old one with you if you're shopping in person.

Matt Roberds

[Andrew Gabriel]

None of the UK sheds will have it. B&Q stock one sodium lamp, and I think that's it for HID lamps. All electrical trade counters will have it in stock, but you probably won't have any choice of colour temperature there. Personally, I prefer warm white for night-time lighting. They usually aren't quite as efficient as the colder/bluer colours though.

[Donwill]

(seems compatible, but claims to be 180mm long - a typo?)

Wilkepedia has some interesting info on Metal Halide Lamps including a large paragraph on Spectral emission (Colour Temperature)

Don