Calculating lamp plus ballast power usage

[tristana]

hi everyone
Please let me know ballast power usage for

150w halide flood lights
250w
400w
and is this usually added to or included in the rating ie 150w plus ballast

im working on spreadsheet for power savings comparing to led versions

thanks alot for your help

 

[Tha fios agaibh]

The info is out there for the taking (internet or light manufacture), but I'll answer part of your question.

The ballast load is not included in the total wattage used in a fixture.
For example; a 400w mh lamp will draw about 1.4 amps at 277 volts mathematically (400/277) but in reality it will draw about 1.8 including ballast and power factor. Older ballasts with a higher power factor will draw even more. (Va X Pf= P)

Basically, a led is about twice the efficiency and three times less maintenance.

The high initial cost makes the return of investment a long way off so it doesn't pay to upgrade if you don't use them much.

Some reading for you:
https://www.myledlightingguide.com/blog-led-vs-metal-halide-lighting