Energy savings for magnetic vs. electronic fluorescent ballasts

[steve66]

Does anyone know the approx. energy savings for replacing a magnetic ballast with an electronic ballast??

3 lamp T8 fixtures.

Steve

 

[gar]

100813-1513 EST

steve66:

I suggest that you run some experiments.

Comparing two 8' Slimline fixtures, both with magnetic ballasts, I got
134 W 29 FC 0.98 PF
102 W 23 FC 0.93 PF
Both fixtures have the same mfg and part number bulbs from the same box and the bulbs have had about the same on time. The ballasts are different.

The intensity differences about correlate with the power differences.

.

 

[steve66]

100813-1513 EST

steve66:

I suggest that you run some experiments.

Comparing two 8' Slimline fixtures, both with magnetic ballasts, I got
134 W 29 FC 0.98 PF
102 W 23 FC 0.93 PF
Both fixtures have the same mfg and part number bulbs from the same box and the bulbs have had about the same on time. The ballasts are different.

The intensity differences about correlate with the power differences.

.

Yes, it looks like the ballasts have different ballast factors (BF's). You can get ballasts that drive the lamps harder than their rated wattage, or ballasts that drive them less. For a popular T5 fixture, I can select a 0.95, 1.0, or 1.15 BF.

From looking at energy star and some similar websites, it looks like the savings can be in the 10% to 20% range.

Steve

 

[gar]

100813-1901 EST

steve66:

I believe the ballasts in the two fixtures were probably made 30 years apart.

I am quite skeptical of so many claims today is the reason I suggested running your own test for comparison. Also what are the unintended consequences?

I would also do an under-voltage test to see where the hot dropout and cold start voltages fall.

.

 

[wireguru]

100813-1901 EST

Also what are the unintended consequences?

.

'green' electronic ballasts that dont outlast the lamps theyre powering