Gallery of Lights
Lamps => Modern => Topic started by: Adderall on May 02, 2011, 06:39:46 AM
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I do not come across the term BF all that often at LG but many mentions of LPF and HPF as a means of categorizing ballasts as if power factor mean something important.
I believe some people erratically apply the term "POWER FACTOR" when they are really talking about BALLAST FACTOR.
Ballast factor is a relative value that is fairly arbitrary and not world wide"
A published spec of "F40T12, nominal 40W, 3300 lumens" in NORTH AMERICA simply mean that it produces 3,300 lumens when operated conditions (temperature, hours of lamp seasoning before taking measurement, etc) as arbitrarily defined in ANSI standards on ANSI "reference ballast". A BF value on a commercially available ballast simply means when that ballast is substituted while everything else remaining equal, the connected lamp will produce lumen output corresponding to catalog value x published BF.
IEC & ANSI as well as other region/country specific testing conditions can overlap, but they're not necessarily the same, so same exact lamp/ballast can have different values just based on the standards used to rate them.
Commercially available ballasts generally range from 0.5 to 1.2. Many lamp manufacturers in the US consider operating at a BF >1.2 as abuse an voids warranty. "full output" T12 ballasts are usually 0.9 to 1.0. Shop lite are usually 0.5 to 0.7. "standard output" electronic T8s are for whatever reason, almost always around 0.88.
Another measure called "ballast efficiency factor" is used in the US and it provides a relative comparison of efficiency of different ballasts operating same type and number of lamps. It is calculated by:
BF x 100/catalog input watt value.
2lamp F32T8 ballast rated at 0.87BF and consumes 55W is therefore, 0.87x100/55 = 1.58
Power Factor:
Power factor simply means the ratio of watts to volt * amp. It measures how effectively wires and power transmission infrastructure is utilized. It is of importance only if the amount of load (i.e. 100 fixtures), they're billed poor power factor penalty and that lighting load lowers the building power factor enough to trigger power factor penalty charge.
Choke ballasts are low power factor, although they can still be "full output" or "BF of near 1.0".
Residential application electronic ballasts are usually low power factor, but are usually "full output" as well.