Lightging pros , reducing bulb wattages

[ransley]

Can I put a 50w Metal Halide bulb in a fixture sold for a 100 w metal Halide light.

Can I put a smaller watt bulb in a 100 w Mercury vapor lamp , maybe a

50 or 75 watt.

[Don Klipstein]

Sadly, in HID fixtures, one needs to match both wattage and "ballast compatibility code".

Exception for need to match wattage, is allowance of slightly-lower- wattage of high pressure sodium to "retrofit" mercury or metal halide. The need to find compatibility via "ballast compatibility code" still exists. Furthermore, some "retrofit sodium" lamps have additional restrictions to ballast types - please know your fixture and read the lamp (bulb) packaging in all ways!

Bad is same-"general-type" lower-than-prescribed-wattage "lamp" ("bulb") for HID (mercury, MH, sodium), tends to overpower the "lamp"/"bulb".

Furthermore, several MH sodium "bulbs" (lamps) come with different "ballast compatibility code" even whenb wattage matches. You need the "bulb" ("lamp") and the ballast (or the fixture) to have at least one of these in common! Otherwise, your lamp may fail to start, or could overheat, or could fail to warm up past 10-20% of full brightness - even if rated wattage matches! Mismatch of wattage (other than "retrofit sodium" slight mismatch in wattage) makes *bad things* more likely!

Good luck!

[Evan]

No, you can not...

You would have to replace the ballast inside the fixture to work with the new desired lamp...

~~ Evan