Ballasts

[kspifldorf]

Can anyone explain to me the difference of a HPS and a MH ballast kit, without getting too involved.

 

[480sparky]

Mostly the output voltage.

To ignite a 70W HPS, the ballast produces about 100-135 volts. MH needs 200-290 volts to strike.

 

[kspifldorf]

Is this the same problem as with say T8 versus T12 bulb/ballast setups?

 

[LarryFine]

Is this the same problem as with say T8 versus T12 bulb/ballast setups?

I'd say it's close enough to consider it the same: they're not interchangeable.

 

[DBack Elec]

Can anyone explain to me the difference of a HPS and a MH ballast kit, without getting too involved.

In the desert we use HPS because MH distorts the night vision for astronomy. There are several major telescopes in the area.

 

[rhogue]

HPS Ballast also have a starter.

 

[iwire]

The main job of a ballast is to limit the current supplied to the lamp.

Metal Halide, Mercury Vapor, or High Pressure sodium lamps of the same wattage all have different current requirements. The voltage supplied to an operating lamp is really a function of the current. If the lamp starts to draw to much current the voltage to the lamp falls.

As 480 sparky pointed out the open circuit voltage of each type ends up being different as well.

Then of course you need different capacitors and some need the external igniter.