Does a 100W HPS need a ballast

[i have no idea]

Hey people im from Australia and have been told that u dont need a ballast for a 70W hps bulb. I have got a 100W Hps bulb that has 100W 240V-250V. When i got it,

it came with a bulb holder and 3 wires coming from the bulb holder (i have got a socket for it).

 

I havent tried anything yet as i dont want to blow the bulb by just plugging it in and turning it on to find that it blows the bulb.

 

As Australia has 240V do i need a ballast for this or not ?

[nouseforaname]

hey,

Im pretty sure even the 100 watt high pressure sodiums need a ballast. Did the light come with the plug or you just have that about. I expect it was cut as it was a one piece ballast and shade combination that was dismantled quickly. Might be wrong thou ..

[boe~pimp]

may i make an inquisition? what does a ballast consist of?

[Tom]

A globe that requires ballast usually has a large size screw in type fitting, the smaller size fittings are the ones that are used for some household lighting. Also the light fitting that the ballasted globe screws into is normally made from ceramic.

 

[Al B. Fuct]

All HPS lighting requires a ballast. If you directly connect an HPS lamp to mains AC, it WILL explode.

 

The techie end of it is that the quartz tube has a negative thermal resistance coefficient; this is to say as it gets hotter, its electrical resistance drops. Without the current limiting function of an inductor in a magnetic ballast (or digital control circuitry in an electronic ballast), the current flow will progressively increase (in a directly-AC mains connected tube) until the fuse on the circuit blows- or the HPS tube explodes.

 

You either need a ballast or a face mask to keep the glass shards out of your eyes.

[Al B. Fuct]

may i make an inquisition? what does a ballast consist of?

 

A typical 'magnetic' ballast for HPS lighting contains an iron cored inductor and an ignitor, which is essentially a snazzy capacitor. The igniter hits the quartz tube with a 1.5-3kV pulse to start the arc, which lowers the resistance of the tube. When the tube reaches a certain current draw, the inductor comes in circuit, in series with the tube, to limit current to the proper level.

 

This site has a pretty good explanation of how inductive ballasts work.