HMI Ballast Questions

[Erica Duffy]

Hello!

I'm trying to learn more about HMI ballasts, can anyone tell me what bates are on a ballast and how I can figure out how many amps they are? Thanks so much!

 

[Frank Martin]

Bates or stage pin connectirs are commen terminating plugs for motion picture work
20/60/100Amp versions

 

[Frank Martin]

here is a cable with bates plugs. one male/ one female. pin always goes to power.

 

[Paul Dean]

Hello!

I'm trying to learn more about HMI ballasts, can anyone tell me what bates are on a ballast and how I can figure out how many amps they are? Thanks so much!

These days there is no direct correlation between the size of the Bates plug on the ballast and the amount of current the HMI lamp will draw. To begin with, only ballasts in the 2.5-4kw range will have a 120V Bates plug on it. But, because of constant improvement in HMI ballast technology over the years you will likely come across different types of HMI ballasts in that range and each will draw a different amount of current. You may come across both magnetic and electronic ballasts; and to complicate matters even more, you may come across two types of electronic ballasts: Power Factor Corrected and non-Power Factor Corrected. To complicate the matter even further there are “Universal” HMI Ballasts that will operate any HMI from a 1.2kw to a 4kw. So depending on the type of ballast and the wattage lamp it is powering, an HMI ballast in that power range may draw from 13 – 52 Amps at 120V. To complicate the matter yet further, most rental houses put a 100A Bates plug on a 2.5/4kw electronic ballast, even though it will draw 52 Amps max, simply because 100A Bates has become the standard on most shows (to carry both 60A and 100A Bates extensions doubles the amount of cable the show carries, so they carry only 100A Bates and use it for lights that will draw half that.)

One of the best resources I have seen online that explains the differences in HMI ballasts and even provides a chart of what lamps will draw depending on the type of ballasts powering it, is a white paper titled “Portable Generators in Motion Picture Production.”

Paul Dean